Podcast
Questions and Answers
Which method uses a biomarker to predict the risk of preterm labour?
Which method uses a biomarker to predict the risk of preterm labour?
What is the significance of a cervical length of less than 25 mm before 24 weeks of gestation?
What is the significance of a cervical length of less than 25 mm before 24 weeks of gestation?
What is the purpose of administering corticosteroids like betamethasone in cases of preterm labour?
What is the purpose of administering corticosteroids like betamethasone in cases of preterm labour?
Which characteristic of preterm labour is not used in the digital cervical examination?
Which characteristic of preterm labour is not used in the digital cervical examination?
Signup and view all the answers
Which screening test is typically not performed during antenatal visits to monitor for pre-eclampsia?
Which screening test is typically not performed during antenatal visits to monitor for pre-eclampsia?
Signup and view all the answers
What is the primary consequence of fetal hyperglycaemia due to excess maternal glucose?
What is the primary consequence of fetal hyperglycaemia due to excess maternal glucose?
Signup and view all the answers
Which effect does high levels of insulin in a newborn primarily lead to after delivery?
Which effect does high levels of insulin in a newborn primarily lead to after delivery?
Signup and view all the answers
Which hormone is specifically associated with increased risks of Down syndrome when elevated levels are found in the triple test?
Which hormone is specifically associated with increased risks of Down syndrome when elevated levels are found in the triple test?
Signup and view all the answers
What role does Human Chorionic Gonadotropin (hCG) play during early pregnancy?
What role does Human Chorionic Gonadotropin (hCG) play during early pregnancy?
Signup and view all the answers
What condition is NOT caused by high levels of insulin in the fetus?
What condition is NOT caused by high levels of insulin in the fetus?
Signup and view all the answers
What is the role of Human Placental Lactogen (hPL) during pregnancy?
What is the role of Human Placental Lactogen (hPL) during pregnancy?
Signup and view all the answers
Which structure allows blood to bypass the fetal lungs?
Which structure allows blood to bypass the fetal lungs?
Signup and view all the answers
What is the primary purpose of the nuchal translucency scan performed during the first trimester?
What is the primary purpose of the nuchal translucency scan performed during the first trimester?
Signup and view all the answers
What does the baseline variability in a cardiotocogram indicate?
What does the baseline variability in a cardiotocogram indicate?
Signup and view all the answers
Which invasive prenatal diagnostic method can be performed from 10 weeks’ gestation?
Which invasive prenatal diagnostic method can be performed from 10 weeks’ gestation?
Signup and view all the answers
Which condition is indicated by the presence of the lemon and banana signs on ultrasound?
Which condition is indicated by the presence of the lemon and banana signs on ultrasound?
Signup and view all the answers
Which test is used to screen for pre-eclampsia during prenatal care?
Which test is used to screen for pre-eclampsia during prenatal care?
Signup and view all the answers
What maternal condition is most commonly associated with increased risk of polyhydramnios?
What maternal condition is most commonly associated with increased risk of polyhydramnios?
Signup and view all the answers
During which trimester is the anomaly scan, involving a detailed structural survey of the fetus, typically performed?
During which trimester is the anomaly scan, involving a detailed structural survey of the fetus, typically performed?
Signup and view all the answers
Which of the following is a potential disadvantage of chorionic villus sampling (CVS)?
Which of the following is a potential disadvantage of chorionic villus sampling (CVS)?
Signup and view all the answers
What is the main contributing factor to the high perinatal mortality rate in twin pregnancies?
What is the main contributing factor to the high perinatal mortality rate in twin pregnancies?
Signup and view all the answers
Which condition is specifically associated with monochorionic twins due to shared placental circulation?
Which condition is specifically associated with monochorionic twins due to shared placental circulation?
Signup and view all the answers
In a dichorionic twin pregnancy, what is the risk percentage for at least one twin suffering from poor growth?
In a dichorionic twin pregnancy, what is the risk percentage for at least one twin suffering from poor growth?
Signup and view all the answers
What is the key feature in the differential diagnosis of preterm labor versus preterm rupture of membranes?
What is the key feature in the differential diagnosis of preterm labor versus preterm rupture of membranes?
Signup and view all the answers
What is the priority in managing a 24-year-old woman diagnosed with pre-eclampsia?
What is the priority in managing a 24-year-old woman diagnosed with pre-eclampsia?
Signup and view all the answers
What is the primary definition of dysfunctional labour as identified?
What is the primary definition of dysfunctional labour as identified?
Signup and view all the answers
Cephalopelvic disproportion (CPD) can be suspected under certain conditions. Which condition specifically indicates its potential presence?
Cephalopelvic disproportion (CPD) can be suspected under certain conditions. Which condition specifically indicates its potential presence?
Signup and view all the answers
What is the most common maternal complication associated with the use of ventouse during delivery?
What is the most common maternal complication associated with the use of ventouse during delivery?
Signup and view all the answers
Which of the following is NOT a prerequisite for the safe use of ventouse during delivery?
Which of the following is NOT a prerequisite for the safe use of ventouse during delivery?
Signup and view all the answers
Which of the following conditions would primarily contraindicate the use of forceps during delivery?
Which of the following conditions would primarily contraindicate the use of forceps during delivery?
Signup and view all the answers
What is the most critical initial response to manage shoulder dystocia during delivery?
What is the most critical initial response to manage shoulder dystocia during delivery?
Signup and view all the answers
Which of the following is associated with primary postpartum hemorrhage?
Which of the following is associated with primary postpartum hemorrhage?
Signup and view all the answers
What is the significance of a positive fibronectin test in the context of maternal assessment?
What is the significance of a positive fibronectin test in the context of maternal assessment?
Signup and view all the answers
What should be administered if preterm premature rupture of membranes (PROM) is confirmed?
What should be administered if preterm premature rupture of membranes (PROM) is confirmed?
Signup and view all the answers
Which statement regarding pregnant women with insulin-dependent diabetes is accurate?
Which statement regarding pregnant women with insulin-dependent diabetes is accurate?
Signup and view all the answers
How does parvovirus B19 affect pregnancy outcomes?
How does parvovirus B19 affect pregnancy outcomes?
Signup and view all the answers
What is the purpose of continuous fetal monitoring during labor for a diabetic patient?
What is the purpose of continuous fetal monitoring during labor for a diabetic patient?
Signup and view all the answers
What is the recommended management of maternal steroids in the case of preterm labor?
What is the recommended management of maternal steroids in the case of preterm labor?
Signup and view all the answers
What is true about beta-haemolytic streptococcus screening during pregnancy?
What is true about beta-haemolytic streptococcus screening during pregnancy?
Signup and view all the answers
Which finding would warrant an ultrasound scan around 20 weeks of gestation for a diabetic patient?
Which finding would warrant an ultrasound scan around 20 weeks of gestation for a diabetic patient?
Signup and view all the answers
What complication can result from neonatal hyperinsulinaemia after delivery?
What complication can result from neonatal hyperinsulinaemia after delivery?
Signup and view all the answers
Which consequence is most likely due to fetal macrosomia related to maternal hyperglycaemia?
Which consequence is most likely due to fetal macrosomia related to maternal hyperglycaemia?
Signup and view all the answers
Which hormone is primarily responsible for maintaining the corpus luteum during the early stages of pregnancy?
Which hormone is primarily responsible for maintaining the corpus luteum during the early stages of pregnancy?
Signup and view all the answers
Hyperglycaemia in a fetus leads to which physiological response?
Hyperglycaemia in a fetus leads to which physiological response?
Signup and view all the answers
What is a likely short-term effect on a newborn due to elevated insulin levels at birth?
What is a likely short-term effect on a newborn due to elevated insulin levels at birth?
Signup and view all the answers
What is the primary advantage of chorionic villus sampling (CVS) compared to amniocentesis?
What is the primary advantage of chorionic villus sampling (CVS) compared to amniocentesis?
Signup and view all the answers
What is a common factor leading to second trimester miscarriage specifically associated with cervical anatomy?
What is a common factor leading to second trimester miscarriage specifically associated with cervical anatomy?
Signup and view all the answers
During the third trimester, which ultrasound measurement is crucial for evaluating fetal well-being?
During the third trimester, which ultrasound measurement is crucial for evaluating fetal well-being?
Signup and view all the answers
Which condition associated with polyhydramnios can lead to complications for monochorionic twins?
Which condition associated with polyhydramnios can lead to complications for monochorionic twins?
Signup and view all the answers
What is the risk percentage of miscarriage associated with mid-trimester amniocentesis?
What is the risk percentage of miscarriage associated with mid-trimester amniocentesis?
Signup and view all the answers
Which structure is responsible for shunting oxygenated blood from the placenta to the fetus?
Which structure is responsible for shunting oxygenated blood from the placenta to the fetus?
Signup and view all the answers
What is the expected outcome when the foramen ovale closes after birth?
What is the expected outcome when the foramen ovale closes after birth?
Signup and view all the answers
Which prenatal screen assesses maternal serum levels for multiple conditions, including Down syndrome?
Which prenatal screen assesses maternal serum levels for multiple conditions, including Down syndrome?
Signup and view all the answers
Which feature on an ultrasound may indicate spina bifida?
Which feature on an ultrasound may indicate spina bifida?
Signup and view all the answers
What screening method is typically used in antenatal care to assess for kidney involvement in pre-eclampsia?
What screening method is typically used in antenatal care to assess for kidney involvement in pre-eclampsia?
Signup and view all the answers
Which of the following classifications of preterm labour occurs between 28 and 34 weeks of gestation?
Which of the following classifications of preterm labour occurs between 28 and 34 weeks of gestation?
Signup and view all the answers
Which method relies on the measurement of cervical length to predict preterm labour?
Which method relies on the measurement of cervical length to predict preterm labour?
Signup and view all the answers
What is the significance of the presence of fetal fibronectin in vaginal secretions?
What is the significance of the presence of fetal fibronectin in vaginal secretions?
Signup and view all the answers
In the context of diagnosing preterm labour, which condition is indicated by regular uterine contractions occurring at least every 10 minutes for one hour?
In the context of diagnosing preterm labour, which condition is indicated by regular uterine contractions occurring at least every 10 minutes for one hour?
Signup and view all the answers
What is the approximate risk percentage of late miscarriage in a dichorionic twin pregnancy?
What is the approximate risk percentage of late miscarriage in a dichorionic twin pregnancy?
Signup and view all the answers
Which complication is most notably associated with very preterm infants that can be mitigated through the use of magnesium sulfate?
Which complication is most notably associated with very preterm infants that can be mitigated through the use of magnesium sulfate?
Signup and view all the answers
What specific complication results from the vascular anastomoses shared by monochorionic twins?
What specific complication results from the vascular anastomoses shared by monochorionic twins?
Signup and view all the answers
Which of these factors notably increases the risk of birth defects in twin pregnancies?
Which of these factors notably increases the risk of birth defects in twin pregnancies?
Signup and view all the answers
During the management of a woman with suspected pre-eclampsia, which assessment is NOT typically performed?
During the management of a woman with suspected pre-eclampsia, which assessment is NOT typically performed?
Signup and view all the answers
What is the primary reason for the increased perinatal mortality rate in twin pregnancies?
What is the primary reason for the increased perinatal mortality rate in twin pregnancies?
Signup and view all the answers
What is indicated by a positive fibronectin test during maternal assessment?
What is indicated by a positive fibronectin test during maternal assessment?
Signup and view all the answers
What should be the primary focus of care for a woman with poorly controlled insulin-dependent diabetes during pregnancy?
What should be the primary focus of care for a woman with poorly controlled insulin-dependent diabetes during pregnancy?
Signup and view all the answers
What complication can arise from a primary parvovirus infection during pregnancy?
What complication can arise from a primary parvovirus infection during pregnancy?
Signup and view all the answers
What is the main reason for administering erythromycin if PROM has been confirmed?
What is the main reason for administering erythromycin if PROM has been confirmed?
Signup and view all the answers
How should insulin therapy be managed during labor for a diabetic patient?
How should insulin therapy be managed during labor for a diabetic patient?
Signup and view all the answers
What diagnostic confirmation is needed for parvovirus primary infection in a pregnant woman?
What diagnostic confirmation is needed for parvovirus primary infection in a pregnant woman?
Signup and view all the answers
What is the recommended approach for monitoring a pregnant woman with a positive HVS for beta-haemolytic streptococcus?
What is the recommended approach for monitoring a pregnant woman with a positive HVS for beta-haemolytic streptococcus?
Signup and view all the answers
In terms of vertical transmission of HIV, what intervention has been shown to reduce the transmission rate during pregnancy?
In terms of vertical transmission of HIV, what intervention has been shown to reduce the transmission rate during pregnancy?
Signup and view all the answers
What best defines primary dysfunctional labour?
What best defines primary dysfunctional labour?
Signup and view all the answers
Which complication is most commonly associated with the use of ventouse during delivery?
Which complication is most commonly associated with the use of ventouse during delivery?
Signup and view all the answers
Which condition is least likely to be treated with oxytocin when suspected?
Which condition is least likely to be treated with oxytocin when suspected?
Signup and view all the answers
What is a significant risk factor for shoulder dystocia during delivery?
What is a significant risk factor for shoulder dystocia during delivery?
Signup and view all the answers
What defines cephalopelvic disproportion (CPD)?
What defines cephalopelvic disproportion (CPD)?
Signup and view all the answers
What is the primary maternal indication for using forceps during delivery?
What is the primary maternal indication for using forceps during delivery?
Signup and view all the answers
Which situation requires urgent Caesarean section due to cord prolapse?
Which situation requires urgent Caesarean section due to cord prolapse?
Signup and view all the answers
What complication can result from fetal hyperinsulinaemia after delivery?
What complication can result from fetal hyperinsulinaemia after delivery?
Signup and view all the answers
During pregnancy, which of the following is NOT a consequence of maternal hyperglycaemia leading to fetal hyperinsulinaemia?
During pregnancy, which of the following is NOT a consequence of maternal hyperglycaemia leading to fetal hyperinsulinaemia?
Signup and view all the answers
Which hormone is associated with increased risks of chromosomal conditions when elevated in the triple test?
Which hormone is associated with increased risks of chromosomal conditions when elevated in the triple test?
Signup and view all the answers
What condition is most directly linked to the presence of increased insulin levels in a fetus?
What condition is most directly linked to the presence of increased insulin levels in a fetus?
Signup and view all the answers
Which of the following physiological changes is NOT directly caused by elevated insulin levels in the fetus?
Which of the following physiological changes is NOT directly caused by elevated insulin levels in the fetus?
Signup and view all the answers
What characterizes early preterm labour in terms of gestational age?
What characterizes early preterm labour in terms of gestational age?
Signup and view all the answers
Which of the following biochemical markers indicates an increased risk of preterm birth when found in vaginal secretions?
Which of the following biochemical markers indicates an increased risk of preterm birth when found in vaginal secretions?
Signup and view all the answers
What is the significance of the cervical funnel shape observed during transvaginal ultrasonography?
What is the significance of the cervical funnel shape observed during transvaginal ultrasonography?
Signup and view all the answers
Which treatment is typically administered to enhance fetal lung maturity in cases of preterm labour?
Which treatment is typically administered to enhance fetal lung maturity in cases of preterm labour?
Signup and view all the answers
During the clinical evaluation for preterm labour, what is a common limitation of the digital cervical examination?
During the clinical evaluation for preterm labour, what is a common limitation of the digital cervical examination?
Signup and view all the answers
What is the primary reason for performing a detailed anomaly scan during the second trimester?
What is the primary reason for performing a detailed anomaly scan during the second trimester?
Signup and view all the answers
Which invasive prenatal diagnostic method is performed at or after 20 weeks of gestation?
Which invasive prenatal diagnostic method is performed at or after 20 weeks of gestation?
Signup and view all the answers
Among the following conditions, which is least likely to be a cause of polyhydramnios?
Among the following conditions, which is least likely to be a cause of polyhydramnios?
Signup and view all the answers
What potential complication can arise from chorionic villus sampling (CVS)?
What potential complication can arise from chorionic villus sampling (CVS)?
Signup and view all the answers
What is a common maternal disease associated with polyhydramnios that necessitates glucose testing?
What is a common maternal disease associated with polyhydramnios that necessitates glucose testing?
Signup and view all the answers
What is the risk of poor fetal growth in monochorionic twins compared to dichorionic twins?
What is the risk of poor fetal growth in monochorionic twins compared to dichorionic twins?
Signup and view all the answers
In a twin pregnancy, which factor contributes predominantly to the increased perinatal mortality rate?
In a twin pregnancy, which factor contributes predominantly to the increased perinatal mortality rate?
Signup and view all the answers
Which of the following statements is true regarding the risk of chromosomal abnormalities in dizygotic twins?
Which of the following statements is true regarding the risk of chromosomal abnormalities in dizygotic twins?
Signup and view all the answers
What is the primary examination conducted to assess maternal and fetal well-being in a case of suspected pre-eclampsia?
What is the primary examination conducted to assess maternal and fetal well-being in a case of suspected pre-eclampsia?
Signup and view all the answers
What key factor should be assessed in history taking for a woman with painful contractions at 30 weeks' gestation?
What key factor should be assessed in history taking for a woman with painful contractions at 30 weeks' gestation?
Signup and view all the answers
What is the primary role of Human Placental Lactogen (hPL) during pregnancy?
What is the primary role of Human Placental Lactogen (hPL) during pregnancy?
Signup and view all the answers
Where is the patent foramen ovale located in the fetal heart?
Where is the patent foramen ovale located in the fetal heart?
Signup and view all the answers
Which of the following describes variable decelerations in fetal heart monitoring?
Which of the following describes variable decelerations in fetal heart monitoring?
Signup and view all the answers
What is indicated by the presence of lemon and banana signs on ultrasound?
What is indicated by the presence of lemon and banana signs on ultrasound?
Signup and view all the answers
What is the function of the ductus venosus in fetal circulation?
What is the function of the ductus venosus in fetal circulation?
Signup and view all the answers
What intervention has been shown to effectively reduce the vertical transmission rate of HIV during pregnancy?
What intervention has been shown to effectively reduce the vertical transmission rate of HIV during pregnancy?
Signup and view all the answers
In the context of a diabetic patient during pregnancy, what is the primary reason for maintaining normoglycaemia during labor?
In the context of a diabetic patient during pregnancy, what is the primary reason for maintaining normoglycaemia during labor?
Signup and view all the answers
Which outcome is associated with a positive HVS for beta-haemolytic streptococcus in a pregnant patient?
Which outcome is associated with a positive HVS for beta-haemolytic streptococcus in a pregnant patient?
Signup and view all the answers
What does a positive nitrazine test indicate in the context of maternal evaluation?
What does a positive nitrazine test indicate in the context of maternal evaluation?
Signup and view all the answers
What is a potential complication for a fetus whose mother is infected with parvovirus B19 during pregnancy?
What is a potential complication for a fetus whose mother is infected with parvovirus B19 during pregnancy?
Signup and view all the answers
What is the primary definition of primary dysfunctional labour?
What is the primary definition of primary dysfunctional labour?
Signup and view all the answers
Which of the following is a common cause of primary dysfunctional labour?
Which of the following is a common cause of primary dysfunctional labour?
Signup and view all the answers
What does Cephalopelvic Disproportion (CPD) imply?
What does Cephalopelvic Disproportion (CPD) imply?
Signup and view all the answers
Which of the following is a prerequisite for using a ventouse during delivery?
Which of the following is a prerequisite for using a ventouse during delivery?
Signup and view all the answers
Which condition is NOT a contraindication for ventouse use?
Which condition is NOT a contraindication for ventouse use?
Signup and view all the answers
What is a common maternal complication associated with the use of forceps?
What is a common maternal complication associated with the use of forceps?
Signup and view all the answers
Which of the following conditions is primarily indicated by shoulder dystocia?
Which of the following conditions is primarily indicated by shoulder dystocia?
Signup and view all the answers
What is the typical incidence of shoulder dystocia during deliveries?
What is the typical incidence of shoulder dystocia during deliveries?
Signup and view all the answers
Which factor primarily contributes to cord prolapse?
Which factor primarily contributes to cord prolapse?
Signup and view all the answers
What step is vital while arranging for a Caesarean section due to cord prolapse?
What step is vital while arranging for a Caesarean section due to cord prolapse?
Signup and view all the answers
What is the main purpose of chorionic villus sampling (CVS)?
What is the main purpose of chorionic villus sampling (CVS)?
Signup and view all the answers
Which factor is NOT a typical indication for recommending CVS?
Which factor is NOT a typical indication for recommending CVS?
Signup and view all the answers
During which weeks of gestation is chorionic villus sampling usually performed?
During which weeks of gestation is chorionic villus sampling usually performed?
Signup and view all the answers
Which technique involves using a thin catheter inserted through the cervix?
Which technique involves using a thin catheter inserted through the cervix?
Signup and view all the answers
What genetic analysis is primarily performed on the chorionic villi obtained during CVS?
What genetic analysis is primarily performed on the chorionic villi obtained during CVS?
Signup and view all the answers
Which of the following conditions can be detected through DNA analysis during CVS?
Which of the following conditions can be detected through DNA analysis during CVS?
Signup and view all the answers
Which term describes the sample taken during a CVS procedure?
Which term describes the sample taken during a CVS procedure?
Signup and view all the answers
What is a common risk associated with chorionic villus sampling?
What is a common risk associated with chorionic villus sampling?
Signup and view all the answers
In which scenario is CVS most likely to be recommended?
In which scenario is CVS most likely to be recommended?
Signup and view all the answers
Which statement accurately describes the transabdominal approach in CVS?
Which statement accurately describes the transabdominal approach in CVS?
Signup and view all the answers
What is the estimated risk of miscarriage following chorionic villus sampling (CVS)?
What is the estimated risk of miscarriage following chorionic villus sampling (CVS)?
Signup and view all the answers
Why is maternal serum alpha-fetoprotein (AFP) testing recommended after CVS?
Why is maternal serum alpha-fetoprotein (AFP) testing recommended after CVS?
Signup and view all the answers
Which of the following statements about the limitations of CVS is true?
Which of the following statements about the limitations of CVS is true?
Signup and view all the answers
What is one of the advantages of chorionic villus sampling (CVS) compared to amniocentesis?
What is one of the advantages of chorionic villus sampling (CVS) compared to amniocentesis?
Signup and view all the answers
Which complication is associated with the transcervical approach to CVS?
Which complication is associated with the transcervical approach to CVS?
Signup and view all the answers
In which scenario would amniocentesis or non-invasive prenatal testing (NIPT) be considered as alternatives to CVS?
In which scenario would amniocentesis or non-invasive prenatal testing (NIPT) be considered as alternatives to CVS?
Signup and view all the answers
What is a potential risk of conducting CVS before 10 weeks of gestation?
What is a potential risk of conducting CVS before 10 weeks of gestation?
Signup and view all the answers
What condition might cause ambiguity in results obtained from CVS?
What condition might cause ambiguity in results obtained from CVS?
Signup and view all the answers
What is a major reason for conducting thorough patient counseling before CVS?
What is a major reason for conducting thorough patient counseling before CVS?
Signup and view all the answers
Which of the following is a disadvantage of chorionic villus sampling compared to amniocentesis?
Which of the following is a disadvantage of chorionic villus sampling compared to amniocentesis?
Signup and view all the answers
Study Notes
Glucose and Insulin in Pregnancy
- Glucose crosses the placenta, while insulin does not.
- Maternal hyperglycemia leads to fetal hyperglycemia.
- Fetal hyperinsulinemia occurs to compensate for hyperglycemia.
- High fetal insulin has growth-promoting effects.
- These effects can cause macrosomia, organomegaly, polycythemia, polyhydramnios, and preterm delivery.
- After delivery, high fetal insulin can lead to hypoglycemia and reduced surfactant production.
- Reduced surfactant production increases the risk of transient tachypnea of the newborn.
Fetal Heart Development
- The foramen ovale is a temporary opening in the intra-atrial septum that allows blood to bypass the lungs.
- The umbilical vein carries oxygenated blood from the placenta and becomes the ligamentum teres after birth.
- The ductus venosus shunts blood away from the liver to the inferior vena cava.
- The foramen ovale directs blood from the superior and inferior vena cava to the left atrium.
Antenatal Care
- The triple test (or quadruple test) is a second-trimester screener for Down syndrome.
- The dating scan is performed between 8-14 weeks to determine gestational age and confirm viability.
- Protein dipstick testing is used to screen for pre-eclampsia by detecting protein in the urine.
Antenatal Imaging and Fetal Assessment
- Baseline variability on a cardiotocogram (CTG) reflects the interplay between the fetal sympathetic and parasympathetic nervous systems, indicating fetal well-being.
- The biophysical profile (BPP) combines ultrasound and CTG to assess fetal well-being by examining fetal breathing, movements, tone, heart rate, and amniotic fluid.
- Variable decelerations are transient decreases in fetal heart rate usually caused by umbilical cord compression.
- Fetal heart rate accelerations are transient increases in fetal heart rate, often occurring in response to fetal movements.
Prenatal Diagnosis
- The lemon and banana signs on ultrasound can be indicative of spina bifida.
- The triple or quadruple test is used to screen for Down syndrome.
- Fragile X syndrome is diagnosed by detecting expanded CGG repeats on the FMR1 gene.
- Klinefelter’s syndrome affects males and is characterized by infertility, testicular dysgenesis, and tall stature.
Preterm Labour
- Preterm labour is the onset of regular uterine contractions resulting in cervical changes before 37 weeks of gestation.
- Early preterm labour occurs before 28 weeks.
- Moderate to late preterm labour occurs between 28 and 34 weeks.
- Late preterm labour occurs between 34 and 36 weeks and 6 days.
Diagnosing Preterm Labour
- Clinical evaluation includes assessing symptoms and signs like contractions, pelvic pressure, vaginal discharge, and cervical change.
- Biochemical markers include fetal fibronectin (fFN), cervicovaginal proinflammatory cytokines, and serum biomarkers.
- Transvaginal ultrasonography is used to measure cervical length and detect funneling.
- Amniocentesis is used to assess fetal lung maturity and rule out infection.
- Non-Stress Test (NST) and Cardiotocography (CTG) are used to monitor fetal well-being and uterine activity.
Antenatal Blood Tests
- A full blood count is used to screen for anemia and thrombocytopenia.
- Blood group and red-cell antibody testing is performed to determine Rh status.
- Maternal blood is screened for hepatitis B, HIV, and syphilis.
- Pregnant women receive prophylactic anti-D if they are Rh-negative.
Antenatal Visit Examination
- Blood pressure is checked to screen for pre-eclampsia.
- The maternal abdomen is palpated to confirm fetal presentation.
- Symphysis-fundal height is measured to screen fetal growth.
Customized Antenatal Care
- Women with conditions like diabetes receive specialized care in dedicated clinics.
Ultrasound in Obstetrics
- Ultrasound is commonly used in all trimesters to assess the fetus and surrounding structures.
- The first trimester scan is used to confirm viability, date the pregnancy, diagnose twin pregnancies, and screen for nuchal translucency.
- The second-trimester anomaly scan is performed at approximately 20 weeks to detect any abnormalities and monitor monochorionic twins.
- The third-trimester scan is used to determine the placental site and assess fetal well-being.
Invasive Prenatal Diagnosis
- Amniocentesis is performed from 15 weeks to term and carries a fetal loss rate of 0.5-1.5%.
- Chorionic villus sampling (CVS) can be performed transabdominally or transvaginally from 10 weeks to term and has a similar fetal loss rate as amniocentesis.
- Cordocentesis involves direct sampling of fetal blood and is usually performed after 20 weeks' gestation.
Second Trimester Miscarriage
- Second-trimester miscarriage is defined as pregnancy loss between 12 and 24 weeks.
- The cause of miscarriage varies depending on the gestational age.
- Chromosomal and structural anomalies are the predominant causes in early second trimester miscarriage.
- Premature labor, uterine overdistension, intrauterine bleeding, ascending infection, and cervical weakness contribute to late second trimester miscarriage.
Polyhydramnios
- Polyhydramnios can have maternal, fetal, and placental causes.
- Maternal causes include poorly controlled diabetes mellitus and maternal red cell antibodies.
- Fetal causes include neuromuscular conditions, gastrointestinal abnormalities, and fetal hydrops.
- Placental causes include twin-to-twin transfusion syndrome.
Twin Pregnancy Complications
- Overall perinatal mortality rate for twins is six times higher than singletons.
- Preterm delivery is the main contributing factor to this high rate.
- Spontaneous preterm delivery is a risk in all twin pregnancies.
- Approximately half of all twin pregnancies deliver prematurely.
- Dichorionic pregnancy has a late miscarriage risk of around 2%.
- Monochorionic twin pregnancy has a late miscarriage risk of 12%.
- Increased risk of poor growth for each twin compared to singleton pregnancies.
- Dichorionic twins have a doubled risk of low birth weight.
- 20% chance of at least one twin suffering poor growth in dichorionic twin pregnancies.
- Monochorionic twins have a doubled risk of poor fetal growth compared to dichorionic twins.
- Twins have at least twice the risk of a birth defect compared to singletons.
- Dichorionic twins have a doubled risk of a structural anomaly.
- Monochorionic twins have four times the risk of a structural anomaly.
- Chromosomal abnormality risk increases with maternal age, regardless of number of fetuses.
- Monozygotic twins have the same risk due to originating from the same egg.
- Dizygotic twins have a doubled risk due to originating from two different eggs.
- Monochorionic twins share vascular anastomoses.
- Imbalance in blood flow through these anastomoses leads to twin-twin transfusion syndrome.
Pre-Eclampsia Management
- Likely diagnosis is pre-eclampsia with possible risk factors.
- Risk factors include family history of pre-eclampsia and multiple pregnancy.
- Requires both maternal and fetal assessment.
- Maternal assessment includes:
- Full blood count to determine platelet count
- Urea and electrolytes to assess renal function
- Liver function tests
- 24-hour urine collection to confirm proteinuria greater than 0.3 g/save
- Urgent mid-stream urine and microscopy to exclude urinary tract infection
- Full medical examination including:
- Neurological examination to check reflexes (brisk in pre-eclampsia)
- Abdominal palpation to assess fetal size
- Cardiotocography (CTG) to assess immediate fetal well-being.
- Delivery should be considered if abnormalities are noted on CTG.
- Ultrasound scan to determine fetal well-being and presentation.
- Pre-eclampsia warrants delivery.
- Vaginal examination to assess cervical favorability for induction.
- If cervix is unfavorable, induce with prostaglandin pessaries.
- If possible, perform an artificial rupture of the membranes.
- Continuous fetal monitoring throughout labor.
- Close observation of maternal blood pressure and urine output with one-to-one midwifery care.
Preterm Labour Management
- Likely diagnoses: preterm labour with or without membrane rupture.
- Take a detailed history to identify risk factors:
- Twin pregnancy
- Uterine abnormalities
- Cervical damage
- Recurrent antepartum haemorrhage
- Sepsis
- Smoking
- Drug use
- Social class
- Diagnosis of preterm labor can be challenging due to vague symptoms.
- Bleeding should be taken seriously.
- Increased need for analgesia might suggest preterm labor.
- Sudden rush of fluid per vaginum is the most reliable sign of PROM (premature rupture of membranes).
- Full physical examination including:
- Abdominal palpation to check for tenderness (suggestive of abruption or chorioamnionitis).
- Speculum examination to assess for pooling of liquor and cervical dilation.
- Assess maternal well-being:
- Blood pressure, pulse and temperature measurements
- Full blood count to check for increased white cell count (indicating infection).
- Perform tests during speculum examination:
- High Vaginal Swab (HVS)
- Fibronectin test (positive increases probability of preterm delivery)
- Nitrazine test (positive indicates PROM)
- Fetal assessment:
- CTG to check for fetal tachycardia (suggestive of infection).
- Ultrasound to assess liquor volume and cervical length (if PROM has been ruled out).
- Give maternal steroids to induce fetal lung maturity.
- Consider tocolysis to allow administration of steroids.
- If PROM confirmed, administer a 10-day course of erythromycin.
- If HVS positive for beta-haemolytic streptococcus, administer intravenous antibiotics during labor.
- If labor continues, initiate continuous fetal monitoring.
Insulin-Dependent Diabetes and Pregnancy
- Poor glucose control increases risk of congenital anomalies and miscarriage during pregnancy.
- Good control substantially reduces these risks.
- Requires hospital care in a joint clinic with obstetrician, diabetic physician, nurses, and dieticians.
- Aim of treatment is to maintain blood glucose levels as close to normal as possible.
- Insulin requirements increase during pregnancy and require careful monitoring.
- Monitor blood glucose levels and haemoglobin A1c for long-term control.
- Increased risk of diabetic ketoacidosis and hypoglycaemia, educate on signs and symptoms.
- Ultrasound scan at 20 weeks to examine for structural anomalies.
- Increased risk that diabetic nephropathy and retinopathy will worsen during pregnancy.
- Complications usually improve post-delivery.
- Increased risk of pre-eclampsia, requiring regular blood pressure and urine monitoring.
- Increased risk of polyhydramnios, associated with increased risk of premature delivery.
- Poor control associated with macrosomia and increased risk of shoulder dystocia.
- Increased unexplained stillbirth rate after 36 weeks requiring careful fetal monitoring.
- During labor, maintain normoglycaemia using a sliding scale of insulin and hourly blood glucose monitoring.
- Continuous fetal monitoring throughout labor due to increased risk.
HIV, Parvovirus, and Beta-Haemolytic Streptococcus
HIV
- Caused by a RNA retrovirus.
- No indication that pregnancy causes disease progression in the mother.
- No evidence that pregnancy increases the risk of progression from HIV to AIDS.
- Increased risk of miscarriage, preterm delivery, and intrauterine growth restriction during pregnancy.
- Vertical transmission occurs in 25-40% of pregnancies without intervention.
- Majority of transmission occurs around the time of delivery and breastfeeding.
- Interventions to reduce vertical transmission:
- Avoid breastfeeding
- Elective Cesarean section
- Antiviral medication late in pregnancy and during the neonatal period.
Parvovirus
- Parvovirus B19 causes slap cheek syndrome in children.
- Infection is asymptomatic in 50% of children and 25% of adults.
- Approximately 15% of infections during pregnancy lead to chronic fetal infection.
- This causes persistent anemia in utero, which may develop into non-immune hydrops.
- Hydrops may resolve spontaneously or require a blood transfusion.
- Primary parvovirus is diagnosed by maternal serum virus-specific IgM.
- If detected, the fetus requires close monitoring for signs of hydrops.
- Parvovirus is not a teratogenic virus.
Beta-Haemolytic Streptococcus
- Asymptomatic bacterial commensal of the gut and genital tract.
- Found asymptomatically in 20-40% of women.
- Can cause severe neonatal infection and death.
- Screening and routine treatment not beneficial due to frequent recolonization.
- Culture in complicated pregnancies or previous preterm delivery is recommended.
- If present (current or previous pregnancy), administer intravenous antibiotics during labor.
- Premature infants, those with prolonged ruptured membranes and growth-restricted fetuses are at higher risk.
Primary Dysfunctional Labour
- Defined as poor progress (less than 1 cm per hour) in the active phase of labor.
- Labour progress depends on three interconnected variables: powers, passages, and passenger.
- Ineffective uterine action is the most common cause, especially in primiparous women.
- Treatment options: rehydration, artificial rupture of membranes, intravenous oxytocin.
- Tight application of the presenting part to the cervix is vital for adequate progress.
- Malpresentations (e.g., brow or breech) may cause slow progress.
- Cephalopelvic disproportion (CPD) is another cause, implying anatomical mismatch.
- CPD can be due to a large head, small pelvis, or combination of both.
- Suspect CPD if labour progresses slowly despite oxytocin, fetal head fails to engage, or shows severe molding and caput.
- Oxytocin may overcome relative CPD of an abnormal presentation, but Cesarean section may be necessary.
- Uterine and cervical abnormalities can also cause delay:
- Unsuspected lower uterine fibroid can prevent fetal head descent.
- Cervical dystocia (due to a non-compliant, scarred cervix) can cause similar issues.
- All situations may necessitate Cesarean section.
Ventouse and Forceps
Ventouse
- Instrument using suction to aid fetal delivery.
- Used for both maternal and fetal indications.
- Maternal indications:
- Exhaustion after prolonged pushing.
- Shortening the second stage (e.g., maternal cardiac disease).
- Fetal indication: suspected fetal compromise in the second stage.
- Contraindications: face presentation, gestation less than 34 weeks, marked bleeding from fetal blood sample site.
- Prerequisites: fully dilated cervix, station below ischial spines, known position, good contractions, empty bladder, adequate analgesia, and maternal cooperation.
- Commonest maternal complication: genital tract trauma.
- Main fetal complications: cephalhaematoma, rarely serious intracranial injuries.
Forceps
- Divided into two groups: non-rotational and rotational forceps.
- Non-rotational forceps:
- Similar maternal and fetal indications to ventouse.
- Have both cephalic and pelvic curve.
- Specific indications: face presentation, bleeding from a fetal blood sample, aftercoming head of a breech presentation, delivery before 34 weeks.
- Can be used to aid fetal head delivery during Cesarean section.
- Kjelland's (rotational) forceps:
- Lack pelvic curve, allowing rotation within the pelvis.
- Additional indications: malpresentations (occipital posterior position, deep transverse arrest).
- Commonest maternal complication: maternal trauma.
- Fetal complications: less likely to cause cephalhaematoma, but may cause rare serious intracranial injuries.
Cord Prolapse, Shoulder Dystocia, and Postpartum Haemorrhage
Cord Prolapse
- Defined as a loop or loops of umbilical cord falling through the cervix in front of the presenting part.
- Associated with prematurity and malpresentations.
- Occurs in approximately 1 in 500 deliveries.
- Diagnosis usually made on vaginal examination due to abnormal CTG.
- If cord is through the vulva, replace and keep warm.
- Urgent Cesarean section required unless cervix is fully dilated and assisted delivery is safe.
- While arranging Cesarean section, place mother in 'head down' position to relieve pressure on umbilical vein.
- Outcome depends on gestational age and other pregnancy complications.
Shoulder Dystocia
- Defined as difficulty delivering the fetal shoulder.
- Incidence between 0.2 and 1.2% of deliveries.
- Risk factors: large fetus, small mother, maternal obesity, diabetes, prolonged first and second stages of labor, assisted vaginal delivery.
- Manage with a sequence of maneuvers to facilitate delivery without fetal damage.
- Call for senior help immediately.
- Avoid excessive traction.
- Hyperflex and abduct legs at the hips.
- Apply suprapubic pressure to adduct fetal shoulders.
- If these fail, more complex maneuvers are required: rotating fetal shoulders and delivering posterior arm.
- Debrief mother and partner following delivery about the events.
Postpartum Haemorrhage
- Defined as excess blood loss (over 500 mL) after delivery.
- Classified as primary (within 24 hours) and secondary (up to 6 weeks).
- Most common cause: uterine atony (90% of cases).
- Initial management:
- Stop bleeding with uterine massage or bimanual compression.
- Maintain uterine contraction with:
- Ergometrine
- High-dose Syntocinon
- Empty the bladder to aid contraction.
- If uterine contraction fails, administer prostaglandin F2-alpha systemically or directly into the myometrium.
- If bleeding persists despite adequate uterine contraction, the next most common cause is genital tract trauma.
- Examination under anesthesia is required to repair damage.
- If bleeding persists, check clotting urgently as disseminated vascular coagulation may be present and needs to be corrected.
Postpartum Pyrexia
- Most common cause of postpartum pyrexia is Urinary Tract Infection (UTI)
- Symptoms of UTI include dysuria, urinary frequency and lower abdominal pain, potentially radiating to the loins.
- Investigate UTI with clean catch urine dipstick analysis for protein and nitrates, microscopy and culture.
- General investigation with Full Blood Count, Urea and Electrolytes for all febrile postpartum women.
- Initiate antibiotic therapy, adjust depending on urine culture results.
Other Postpartum Infections
- Endometritis often presents with fever, rigors and offensive vaginal discharge.
- Investigate endometritis with vaginal swab and commence antibiotics.
- Breast engorgement & infective mastalgia present with breast pain and erythema.
- Manage breast engorgement and infective mastalgia with anti-inflammatories and antibiotics if infection is suspected.
- If breast abscess present, incision and drainage required.
Other Causes of Postpartum Pyrexia
- Chest infections should be excluded, especially in patients with underlying respiratory conditions (like asthma).
- Chest infection symptoms include productive cough and evidence of lung consolidation.
- Investigate with sputum culture and manage with antibiotics, oxygen therapy, and physiotherapy.
- Deep Vein Thrombosis (DVT) can present with postpartum pyrexia, leg pain, swelling, and calf tenderness.
- DVT diagnosis confirmed by Duplex Doppler Ultrasound and treated with anticoagulants.
- Pulmonary embolism can also present with pyrexia.
- Investigate for pulmonary embolism using ventilation/perfusion (V/Q) scan and treat with anticoagulants.
Psychiatric Sequelae of Pregnancy
- Disturbances in emotional state are common in the postnatal period.
- Up to 80% of women experience some emotional alteration.
- Most common between days 3-10 postpartum.
- Mild postnatal depression affects 7% of women primarily between days 3 and 10 postpartum, linked to social adversity, single status, and poor support.
- Symptoms of mild postnatal depression include insidious onset insomnia and difficulty coping.
- Counseling is an effective treatment for mild postnatal depression, as effective as antidepressant therapy.
- Severe postnatal depression occurs in 3-5% of women and may be detected at the 6-week postnatal check using the Edinburgh postnatal score.
- Symptoms of severe postnatal depression include early morning awakening, altered appetite, and anhedonia (loss of pleasure).
- Management of severe postnatal depression includes explanation, reassurance, and tricyclic antidepressant therapy (results observed within 2 weeks).
- Continue tricyclic antidepressant therapy for 6 months.
- Postpartum psychosis affects 2 in 1000 women, presenting with acute mania or depression.
- Manage postpartum psychosis with sedation using neuroleptic drugs.
- Psychiatric assessment by a specialist recommended with admission to a mother and baby unit.
- Oral neuroleptic agents like haloperidol are commonly used with procyclidine for extrapyramidal side effects.
- Lithium carbonate can be used for women presenting with manic pathology.
- First line treatment for severe depression is electroconvulsive therapy (ECT).
- Continue treatment for at least 6 months with a 50% recurrence rate.
Hypertension in Pregnancy
- Hypertension during pregnancy can lead to serious maternal and fetal complications such as eclampsia, placental abruption, and fetal growth restriction.
- Pre-eclampsia characterized by vasospasm and endothelial dysfunction, leading to increased vascular resistance, reduced organ perfusion, and potentially systemic complications (e.g., HELLP syndrome—hemolysis, elevated liver enzymes, low platelets).
Symphysis-Fundal Height (SFH) Measurement
- From top of uterus (fundus) to the symphysis pubis.
- Purpose: Estimate gestational age, screen for conditions like IUGR (Intrauterine Growth Restriction) or polyhydramnios.
- Fundal height larger than expected: Suspect polyhydramnios, multiple gestations, or macrosomia.
- Fundal height smaller than expected: Suggests IUGR or oligohydramnios, prompting further investigation such as Doppler ultrasound for placental insufficiency.
- Palpation of maternal abdomen assesses fetal presentation (cephalic, breech, transverse), lie, and position.
- Importance: Determines engagement of the fetal head in the pelvic inlet, which is crucial for labor management.
Customized Antenatal Care
- Tailored care protocols for specific risk factors or medical conditions complicating pregnancy.
- High-risk conditions like gestational diabetes mellitus (GDM), hypertensive disorders, or autoimmune diseases require specialized management and multidisciplinary team involvement.
- Diabetes-specific care requires strict glycemic control to prevent fetal complications (e.g., macrosomia, congenital anomalies, neonatal hypoglycemia).
- Monitor with frequent glucose testing, adjustments in insulin therapy, HbA1c levels for long-term glycemic control, and serial growth scans for macrosomia.
- Women with pre-existing or pregnancy-induced hypertension require frequent blood pressure monitoring and assessment for pre-eclampsia related complications (e.g., proteinuria).
- Customized care ensures close monitoring of high-risk pregnancies, enabling early intervention, and minimizing adverse outcomes.
Use of Ultrasound In Obstetrics
-
First Trimester:
- Purpose: Establish pregnancy viability, determine gestational age, and detect multiple pregnancies.
- Early screening for anomalies with nuchal translucency measurement and maternal serum markers for chromosomal anomalies like Down syndrome.
- Detecting chorionicity in twins is crucial for anticipating complications such as twin-twin transfusion syndrome (TTTS).
-
Second Trimester:
- Anomaly scan for detecting structural anomalies
- Uterine artery Doppler for increased risk of pre-eclampsia by assessing resistance in the uterine arteries.
- Cervical length assessment for predicting preterm labor, particularly in women with a history of cervical incompetence or prior preterm deliveries.
-
Third Trimester:
- Growth scans and Doppler studies for fetal growth, placental function, and amniotic fluid volume.
- Biophysical profile and umbilical artery Doppler assess fetal well-being and can predict fetal hypoxia or acidosis.
Techniques for Invasive Prenatal Diagnosis
-
Amniocentesis:
- Performed after 15 weeks for genetic testing, assessing for neural tube defects, and evaluating fetal lung maturity in cases of preterm labor risk.
- Complications: Risk of miscarriage (0.5-1.5%), infection, or preterm labor.
- Diagnostic Yield: Provides karyotyping and biochemical testing (Trisomy 21) or alpha-fetoprotein (AFP) levels for neural tube defects.
-
Chorionic Villus Sampling (CVS):
- Performed between 10-12 weeks gestation.
- Advantage: Earlier diagnosis compared to amniocentesis.
- Risks: Higher rate of fetal loss compared to amniocentesis due to contamination by maternal cells or placental mosaicism.
-
Cordocentesis:
- Sampling of fetal blood from the umbilical vein.
- Used for diagnosing fetal infections, hemoglobinopathies, or severe anemia.
- Complications: Higher risk procedure, typically reserved for cases where amniocentesis or CVS is not diagnostic.
Second Trimester Miscarriage
- Loss occurring between 12 and 24 weeks gestation.
- Commonly caused by chromosomal abnormalities (early second trimester), uterine anomalies, cervical incompetence, or intrauterine infections.
- Cervical incompetence leads to painless cervical dilatation, premature rupture of membranes, and subsequent miscarriage.
- Management includes cerclage for cervical incompetence, antibiotic treatment, and monitoring for signs of chorioamnionitis (infection of the membranes surrounding the fetus).
Cerclage
- Definition: A surgical procedure to place a suture around the cervix to prevent or treat cervical incompetence or insufficiency.
- Reinforces the cervix to prolong pregnancy and is typically performed during the second trimester.
- Indications for Cerclage:
- Prophylactic: History of two or more consecutive second-trimester miscarriages due to painless cervical dilatation or prior preterm birth (before 34 weeks) due to painless cervical dilatation or cervical insufficiency.
- Therapeutic: Shortened cervical length (1–2 cm) in the second trimester, often accompanied by bulging amniotic membranes.
Grades of Cervical Cerclage:
-
McDonald Cerclage:
- Most commonly performed.
- Purse-string suture placed around the cervix at the cervicovaginal junction.
- Less invasive and easily removed at 36–37 weeks gestation or at onset of labor.
-
Shirodkar Cerclage:
- Deeper suture placement.
- Requires dissection of the vaginal mucosa and specialized techniques to remove at term.
- Provides stronger support for the cervix but more technically challenging.
-
Transabdominal Cerclage:
- Used when a transvaginal cerclage is not feasible (anatomical constraints or prior failed cerclage).
- Performed laparoscopically or via laparotomy at the level of the internal os.
- Requires Cesarean Delivery for subsequent births as the cerclage is left in place.
Cerclage Procedure Steps:
-
Anesthesia:
- Typically performed under regional (spinal or epidural) anesthesia.
- General anesthesia if needed.
-
Positioning:
- Lithotomy position, cervix is visualized using a Sims or Cusco’s speculum.
-
Cervical Preparation:
- Cervix is grasped with atraumatic forceps (e.g., Allis forceps) for gentle traction and exposure.
- Vaginal mucosa cleansed with an antiseptic solution.
-
Suture Placement:
-
McDonald Cerclage:
- Non-absorbable suture (e.g., Mersilene or Prolene) in a purse-string manner circumferentially around the cervix at the cervicovaginal junction.
- Suture tied anteriorly, knot must not obstruct the cervical canal.
-
Shirodkar Cerclage:
- Transverse incision made in the anterior vaginal mucosa to access the cervix.
- Suture placed at the level of the internal os, beneath the mucosa tied anteriorly or posteriorly.
-
Transabdominal Cerclage:
- Performed laparoscopically or via laparotomy.
- Suture placed at the level of the internal cervical os, using either a band or a non-absorbable material.
- The suture is tied anteriorly or posteriorly.
-
McDonald Cerclage:
-
Closure and Confirmation:
- Mucosal incision closed with absorbable sutures for Shirodkar cerclage.
- Cerclage is confirmed for secure placement and non-obstruction of the cervical canal.
-
Postoperative Care:
- Monitor for infection, contractions, or premature rupture of membranes.
- Bed rest may be advised for 24–48 hours, avoid strenuous activities.
- Serial ultrasounds recommended to monitor cervical length and suture integrity.
Cerclage Removal:
- For McDonald and Shirodkar cerclages, typically removed at 36–37 weeks or earlier if labor ensues.
- Transabdominal cerclage may remain in place for subsequent pregnancies.
Complications of Cervical Cerclage:
-
Immediate:
- Premature rupture of membranes.
- Infection (chorioamnionitis).
- Cervical laceration during suture placement.
-
Late:
- Uterine contractions leading to preterm labor.
- Cervical dystocia or stenosis.
Postoperative Complications:
- Preterm premature rupture of membranes (PPROM).
- Bleeding.
- Fetal loss or preterm delivery.
Perinatal Mortality Rate
- The number of stillbirths and early neonatal deaths per 1000 live births and stillbirths.
Causes of Perinatal Mortality:
- Congenital anomaly
- Severe immaturity
- Infection
- Intracranial haemorrhage
- Isoimmunization
- Unknown
Management of Preterm Labor
- Maternal steroids and surfactant.
Classification of Perinatal Mortality
- Extended Wriggleworth
- Obstetric (Aberdeen) classification
- Fetal and neonatal factor classification
Conception, Implantation and Embryology
- Oocyte: The female reproductive cell.
- Zona pellucida: A glycoprotein layer surrounding the oocyte.
- Granulosa cells: Cells surrounding the oocyte.
- Follicular fluid: Fluid within the follicle that surrounds the oocyte.
Meiosis
- Meiosis begins with diploid cells.
- Initial cell division leads to two haploid daughter cells.
- During the second division, no DNA replication occurs.
- 23 double-stranded chromosomes separate into single-stranded chromosomes to form the nucleus of each daughter cell.
First Signs of Pregnancy
- Missed period.
- Pregnancy test measures the hormone human chorionic gonadotrophin (hCG).
- Commercial available kits are sensitive to 25 IU/L in urine.
- Quantitative serum hCG assay levels greater than 15 IU /L will usually denote a pregnancy.
- Ultrasound:
- Transvaginal ultrasound demonstrates a gestation sac 4–5 weeks after the last menstrual period, fetal heart between 5 and 6 weeks.
- Abdominal ultrasound demonstrates a gestation sac 5-6 weeks after the last menstrual period, fetal heart a week later.
Physiological Changes in Pregnancy
- Cardiovascular changes occur early in gestation.
- 10–20 per cent increase in maternal heart rate.
- 10 per cent increase in stroke volume.
- Increases cardiac output by 30–50 per cent.
- Decreases maternal mean arterial pressure and peripheral vascular resistance.
Human Chorionic Gonadotrophin (hCG)
- Composed of α and β subunits.
- hCG levels increase dramatically in the first 10 weeks.
- Decreases in concentration after 10 weeks, plateaus at 12 weeks for the remainder of pregnancy.
- Maintains the function of the corpus luteum and production of progesterone in early pregnancy.
Prolactin
- Increases throughout pregnancy.
- Does not promote lactation during pregnancy, as its function is antagonized by estrogen.
- Rapid fall in estrogen within the first 48 hours after birth enables lactation.
- Early sucking promotes prolactin release.
- Oxytocin causes contraction of myoepithelial cells and milk expression.
- Prolactin increases milk synthesis.
Normal Fetal Development
-
Cardiovascular System:
- Extensive remodelling at birth under the changed haemodynamics of the activated pulmonary system.
- Cessation of umbilical blood flow in the ductus venosus causes a fall in the right atrial pressure and closure of the foramen ovale.
- Ventilation of the lungs opens the pulmonary circulation, with a rapid fall in pulmonary vasculature resistance.
- Ductus arteriosus closes functionally within a few days of birth.
-
Lungs:
- Fluid within the lungs is reabsorbed.
- Chest compression at delivery forces out approximately one-third of the fluid, release of adrenalin promotes reabsorption of the rest.
- Surfactant is released, triggered by adrenalin and steroids.
- Fall in capillary pressure of the lungs occurs with the expansion of the alveoli and the vasodilatory effect of oxygen.
- Respiratory movements of the chest commence.
Respiratory Distress Syndrome (RDS)
- May lead to hypoxia.
- Antenatal steroids administered to the mother reduces the risk and severity of RDS.
- Severity of RDS can be reduced by the administration of surfactant.
Preterm Infant Complications
-
Hypothermia:
- Common due to the large surface area, lack of subcutaneous fat, and keratinized skin.
- Management: Nursing the infant in an incubator.
-
Dehydration:
- Due to large surface area.
- Management: Nursing the infant in an incubator.
-
Jaundice:
- Secondary to liver immaturity.
- Management: Phototherapy.
Periventricular Haemorrhage and Intraventricular Haemorrhage
- Commonly lead to cerebral palsy.
Routine Prenatal Screening
- Full blood count: Screens for anaemia and thrombocytopenia.
- Maternal blood group: Determines blood group for cross-matching later.
- Rhesus status: Determines rhesus status, prophylaxis offered if rhesus negative at 28 and 34 weeks gestation.
- Rubella status: Determines rubella status, maternal rubella infection can have serious consequences for the baby.
Antenatal Care
- Women who are not immune to hepatitis B should avoid contact with infected individuals.
- All pregnant women should be offered HIV testing.
- Antiretroviral agents, elective Caesarean section, and avoidance of breastfeeding can reduce vertical HIV transmission to less than 5%.
Second Trimester Screening
- At around 15 weeks, all pregnant women should be offered the triple test to assess the risk of Down's Syndrome.
Third Trimester Monitoring
- Blood pressure should be monitored at all antenatal visits, especially during the late second and early third trimester to screen for pre-eclampsia.
- Urine should be analyzed for protein, blood, and glucose at all antenatal appointments to detect infection, pre-eclampsia, and gestational diabetes.
Elective Cesarean Section
- A surgical procedure to deliver a baby through an incision in the abdomen and uterus.
- Often recommended for breech presentations with associated risk factors.
- Indicated for previous uterine surgery, placental complications, or large fetal size.
- The Term Breech Trial indicated that Caesarean section reduces perinatal mortality and morbidity compared to vaginal delivery for breech births.
External Cephalic Version (ECV)
- Procedure to manually turn a breech baby into a cephalic position through the maternal abdomen.
- Performed between 36-37 weeks of gestation.
- Contraindicated in placenta previa, oligohydramnios, multiple pregnancies, prior Caesarean section, and pre-eclampsia.
- Risks include placental abruption, cord prolapse, transplacental hemorrhage, or fetal bradycardia.
Vaginal Breech Delivery
- Suitable for normal-sized fetuses with a flexed head in multiparous women with no contraindications.
- The fetal presentation should be deeply engaged.
- Increased risk of birth asphyxia, fetal injury, and higher perinatal morbidity and mortality compared to elective Caesarean sections.
Monozygotic Twins
- Arise from a single fertilized ovum that splits in two.
- The timing of the split determines chorionicity and amnionicity.
- Chorionicity is best determined at the end of the first trimester.
- Dichorionic twins show a 'lambda' sign, indicating placental tissue extension into the intertwin membrane base.
- Monochorionic twins lack this sign, and the membrane joins the uterine wall in a 'T' shape.
Risks and Complications of Twin Pregnancies
- Increased risk of intrauterine growth restriction (IUGR), especially in monochorionic twins.
- Higher risk of preterm labor, leading to increased perinatal morbidity and mortality.
- Twin-to-Twin Transfusion Syndrome (TTTS) is a serious complication in monochorionic twins due to vascular anastomoses, resulting in volume imbalance and growth discrepancies.
Management of Twin Pregnancies
- Close monitoring with regular ultrasound assessments for growth, fluid volume, and Doppler studies.
- Timely intervention when complications arise.
Pre-eclampsia
- Defined by new-onset hypertension (BP ≥140/90 mmHg) and proteinuria (≥0.3g/24h) after 20 weeks of gestation.
- Clinical features include headache, visual disturbances, hypereflexia, clonus, papilledema, and small for gestational age fetus.
- Complications can include eclampsia, renal failure, cerebrovascular accidents, and adult respiratory distress syndrome.
Management of Pre-eclampsia
- Maternal assessment and blood pressure control with antihypertensive agents like labetalol.
- Close monitoring for disease progression.
- Fetal assessment through regular ultrasound and Doppler scans for fetal wellbeing.
- Delivery recommended when maternal or fetal condition worsens, typically after 34 weeks gestation.
Preterm Labor
- Defined as the onset of labor before 37 completed weeks of gestation.
Diagnostic Evaluation of Preterm Labor
- Clinical history and physical exam to identify risk factors like multiple gestations, uterine anomalies, or history of preterm delivery.
- Investigations include fetal fibronectin test, transvaginal ultrasound to measure cervical length, and speculum examination for pooling of amniotic fluid to diagnose preterm rupture of membranes (PROM).
Management of Preterm Labor
- Tocolysis with medications like nifedipine or atosiban to delay labor and allow for steroid administration for fetal lung maturation.
- Administer corticosteroids (e.g., betamethasone) to promote fetal lung maturity.
- Antibiotics are indicated for women with PPROM to reduce the risk of intra-amniotic infection and neonatal sepsis.
Prognosis of Preterm Labor
- The risk of neonatal complications increases with decreasing gestational age.
- Outcomes are generally poor below 24 weeks but improve significantly after 28 weeks.
Medical Diseases in Pregnancy: Cardiac Disease
- Complicates approximately 1% of pregnancies.
- Can lead to significant maternal and fetal morbidity and mortality.
- Common conditions include mitral stenosis, aortic stenosis, cardiomyopathy, and congenital heart disease.
Management of Cardiac Disease in Pregnancy
- Involves a multidisciplinary team including cardiology, obstetrics, and anesthesiology.
- Vaginal delivery is preferred unless contraindicated.
- The second stage of labor should be shortened to reduce maternal cardiac strain.
- Beta-blockers, like labetalol, can be used, but drugs such as ACE inhibitors are contraindicated due to fetal risks.
HIV in Pregnancy
- HIV is a single-stranded retrovirus that binds to CD4 receptors.
- T-helper lymphocytes, macrophages, dendritic cells, and microglia cells present CD4 receptors.
- Two main treatment strategies:
- Antiretroviral therapy (Highly Active Antiretroviral Therapy - HAART) is commenced if there is no evidence of immunodeficiency. HAART combines several drugs, including nucleoside reverse transcriptase inhibitors, a non-nucleoside reverse transcriptase inhibitor, and a protease inhibitor.
- If immunodeficiency is present, treatment focuses on preventing opportunistic infections.
- Vertical transmission occurs in 25-40% of pregnancies without interventions.
- Three interventions to reduce vertical HIV transmission: avoidance of breastfeeding, elective Caesarean section, and the use of antiviral drugs in the later half of pregnancy and the neonatal period.
Glucose and Insulin in Pregnancy
- During pregnancy, maternal glucose is transported across the placenta, but insulin is not.
- High maternal glucose levels can lead to fetal hyperglycemia.
- To compensate, the fetus increases its own insulin levels, causing hyperinsulinemia.
- Hyperinsulinemia can lead to several complications:
- Macrosomia (increased fetal size)
- Organomegaly (enlarged organs, particularly the heart)
- Erythropoiesis (increased red blood cell production, leading to polycythemia)
- Polyhydramnios (excess amniotic fluid)
- Increased risk of preterm delivery
- After delivery, the fetus still has high insulin levels but no longer receives glucose from the mother, increasing the risk of hypoglycemia.
- Regular feeding is important after birth to prevent hypoglycemia.
- High insulin can also reduce pulmonary phospholipids, which decrease fetal surfactant production.
- Surfactant is essential for reducing surface tension in the alveoli, aiding gas exchange.
- Infants with reduced surfactant production are at risk of transient tachypnea of the newborn.
Triple Test
- The triple test is a prenatal screening test performed during the second trimester (15-20 weeks) to assess the risk of Down syndrome, Edwards syndrome, and neural tube defects.
- It measures levels of Alpha-Fetoprotein (AFP), Human Chorionic Gonadotropin (hCG), and Inhibin-A.
- Inhibin-A is a hormone produced by the placenta and ovaries. Elevated levels may indicate an increased risk of Down syndrome.
Human Chorionic Gonadotropin (hCG)
- hCG is produced by the trophoblast cells of the placenta and continues to be secreted throughout pregnancy.
- Levels peak around 10-12 weeks of gestation, then decrease and stabilize by mid-pregnancy.
- hCG directly supports the corpus luteum during early pregnancy, stimulating progesterone production, essential for maintaining the endometrium.
Human Placental Lactogen (hPL)
- hPL is a pregnancy-specific hormone with weak thyrotrophic activity.
- It's secreted by the syncytiotrophoblast cells of the placenta.
- It promotes maternal lipolysis and protein synthesis, providing glucose and amino acids for the fetus.
Fetal Heart Development
- The patent foramen ovale, a crucial opening in the intra-atrial septum during fetal life, allows blood to pass from the right atrium to the left atrium, bypassing the lungs.
- The foramen ovale typically closes after birth when the baby takes its first breaths and the pressure in the left atrium rises above the right atrium.
- The umbilical vein carries oxygenated blood from the placenta to the fetus. After birth, it closes and becomes the ligamentum teres (round ligament of the liver), part of the falciform ligament.
- Blood flow from the inferior and superior vena cava is directed through the foramen ovale in neonatal life, bypassing the non-functioning fetal lungs.
- The ductus venosus is a fetal vessel that shunts a portion of the umbilical vein blood flow directly to the inferior vena cava, bypassing the liver. This helps deliver oxygen-rich blood to the heart and brain quickly.
Antenatal Care
- The triple test (or quadruple test if Inhibin-A is included) is a second trimester screening test for Down syndrome and neural tube defects.
- A dating scan, performed between 8-14 weeks of gestation, confirms fetal viability and determines gestational age.
- Protein dipstick testing is a method for screening pre-eclampsia by detecting protein in the urine, a sign of kidney involvement.
Fetal Assessment
- Baseline variability on a cardiotocogram (CTG) reflects the interplay between the fetal sympathetic and parasympathetic nervous systems, indicating fetal well-being.
- The biophysical profile (BPP) combines ultrasound and CTG to assess fetal well-being, evaluating fetal breathing, movements, tone, heart rate, and amniotic fluid volume.
- Variable decelerations are abrupt decreases in fetal heart rate lasting at least 15 seconds, often caused by umbilical cord compression.
- Fetal heart rate accelerations are transient increases in fetal heart rate, often occurring in response to fetal movements or contractions, indicating fetal well-being.
Prenatal Diagnosis
- The lemon and banana signs are ultrasonographic markers for spina bifida, indicating a lemon-shaped fetal skull and a banana-shaped cerebellum.
- The triple or quadruple test measures maternal serum hormones to screen for Down syndrome.
- Fragile X syndrome is diagnosed by detecting an expanded number of CGG repeats (>200) on the FMR1 gene, usually through amniocentesis or chorionic villus sampling (CVS).
- Klinefelter's syndrome (47,XXY) presents in males with tall stature, testicular dysgenesis, infertility, and slightly reduced intelligence.
Preterm Labour
- Preterm labour is defined as the onset of regular uterine contractions leading to progressive cervical changes before 37 completed weeks of gestation.
- Preterm labour results in preterm birth, a significant cause of neonatal morbidity and mortality.
- Preterm labour is classified based on gestational age:
- Early Preterm Labour: Occurs before 28 weeks of gestation
- Moderate to Late Preterm Labour: Occurs between 28 and 34 weeks
- Late Preterm Labour: Occurs between 34 and 36 weeks and 6 days
Diagnosing Preterm Labour
- Diagnosing preterm labour involves clinical assessment, biochemical markers, and imaging techniques:
-
Clinical Evaluation:
-
Symptoms and Signs:
- Regular contractions occurring at least every 10 minutes for one hour
- Pelvic pressure or lower abdominal pain
- Vaginal discharge or bleeding
-
Digital Cervical Examination:
- Assessing cervical dilatation (≥ 2 cm) and/or effacement (≥ 80%).
-
Symptoms and Signs:
-
Biochemical Markers:
-
Fetal Fibronectin (fFN):
- Present in vaginal secretions between 22 and 34 weeks, it indicates an increased risk of preterm birth.
-
Cervicovaginal Proinflammatory Cytokines (e.g., IL-6, IL-8):
- Elevated levels suggest inflammation or infection, a trigger for preterm labour.
-
Serum Biomarkers:
- Serum markers like placental alpha microglobulin-1 (PAMG-1) or insulin-like growth factor-binding protein-1 (IGFBP-1) predict preterm labour.
-
Fetal Fibronectin (fFN):
-
Transvaginal Ultrasonography (TVS):
-
Cervical Length Measurement:
- A cervical length of less than 25 mm before 24 weeks predicts preterm labour.
-
Cervical Funnel Shape:
- The presence of funneling indicates cervical incompetence and increased risk of preterm birth.
-
Cervical Length Measurement:
-
Amniocentesis:
- Performed to rule out intra-amniotic infection or assess fetal lung maturity.
- Elevated white blood cell count or positive bacterial cultures indicate chorioamnionitis, triggering preterm labour.
-
Non-Stress Test (NST) and Cardiotocography (CTG):
- Used to monitor fetal well-being and uterine activity.
- Regular uterine contractions detected on CTG alongside cervical changes confirm preterm labour.
-
Clinical Evaluation:
Early Diagnosis of Preterm Labour
- Early diagnosis of preterm labor allows timely interventions:
- Tocolytics (e.g., nifedipine, atosiban) to suppress uterine contractions and delay delivery.
- Corticosteroids (e.g., betamethasone) to accelerate fetal lung maturity and reduce neonatal complications.
- Magnesium sulfate for fetal neuroprotection, reducing the risk of cerebral palsy in very preterm infants.
Antenatal Blood Tests
- During antenatal care, several blood tests are routinely performed:
- Full blood count: Screens for anemia and thrombocytopenia
- Blood group and red-cell antibodies: Determines Rh status and identifies potential complications during pregnancy.
- Prophylactic anti-D administration: Offered to Rh-negative mothers at 28 and 32 weeks of gestation to prevent sensitization.
- Hepatitis B, HIV, and syphilis screening: Initiates appropriate treatment if positive.
- Antiviral drugs and Cesarean section: Offered to HIV-positive mothers during pregnancy.
- Active and passive immunization: Fetus is actively and passively immunized at birth if the mother is a carrier or has a recent infection.
- Antibiotics: Syphilis is treated with high-dose maternal antibiotics.
Antenatal Visit Examination
- Each antenatal visit includes:
- Blood pressure testing: Screens for pre-eclampsia
- Maternal abdomen palpation: Confirms fetal presentation.
- Symphysis-fundal height measurement: Screens for fetal growth.
Customized Antenatal Care
- Women with risk factors not addressed by standard care should be referred for customized antenatal care.
- For example, women with diabetes receive specialized care within a dedicated clinic.
Ultrasound in Obstetrics
- Ultrasound plays a crucial role throughout all gestations, assessing the fetus and surrounding structures.
-
First Trimester:
- Confirms fetal viability, accurate dating, and diagnoses twin pregnancies.
- Determines chorionicity in twin pregnancies.
- Detects uterine abnormalities and ovarian cysts.
- Allows for nuchal translucency screening.
-
Second Trimester:
- Anomaly scan, conducted at approximately 20 weeks, provides a detailed structural survey of the fetus to identify any abnormalities.
- Uterine artery Doppler scans assess the risk of pre-eclampsia.
- Cervical length assessment determines the risk of preterm labour.
- Monochorionic twins are assessed for signs of twin-to-twin transfusion.
-
Third Trimester:
- Determines the placental site.
- Assesses fetal well-being using fetal growth parameters, liquor volume, and umbilical artery Doppler measurements.
Invasive Prenatal Diagnosis
-
Amniocentesis:
- Most common diagnostic test, performed from 15 weeks to term.
- Used for high-risk pregnancies identified by previous screening or history.
- Performed transabdominally with a needle.
- Fetal loss rate of 0.5–1.5%.
-
Chorionic Villus Sampling (CVS):
- Alternative to amniocentesis.
- Performed transabdominally or transvaginally from 10 weeks to term.
- Similar fetal loss rate to amniocentesis.
- Potential disadvantages include contamination by maternal cells or placental mosaicism, leading to false-negative results or interpretation difficulties.
-
Cordocentesis:
- Direct sampling of fetal blood from the umbilical vein.
- Performed at or after 20 weeks of gestation.
Second Trimester Miscarriage
- Second trimester miscarriage occurs between 12 and 24 weeks of gestation.
-
Possible Aetiologies:
- 12-15 weeks: Predominantly due to fetal chromosomal and structural anomalies, similar to first trimester losses.
- Mid-trimester Amniocentesis: A specific iatrogenic risk factor, performed between 16 and 18 weeks, with a 1 in 200 miscarriage risk.
-
19-23 weeks: Commonest causes are linked to premature labor.
- Uterine Overdistension: This from multiple pregnancy or polyhydramnios increases myometrial contractions, premature cervical shortening, and opening.
- Intrauterine Bleeding: Irritates the uterus, leading to contractions, membrane damage, and early rupture.
- Ascending Infection: May pass through the cervix, reaching the fetal membranes, stimulating prostaglandin release and uterine contractions.
- Cervical Weakness: Caused by previous surgical injury or congenital defects, leads to premature cervical shortening and opening, resulting in membrane prolapse and potential damage.
Polyhydramnios
- Polyhydramnios is an excess of amniotic fluid.
-
Possible Causes:
-
Maternal:
- Poorly controlled diabetes mellitus.
- Isoimmunization due to maternal red cell antibodies.
-
Fetal:
- Neuromuscular conditions that interfere with fetal swallowing, leading to fluid accumulation.
- Fetal gastrointestinal abnormalities, including esophageal and duodenal atresia, blocking amniotic fluid ingestion.
- Fetal hydrops, associated with cardiac failure or anemia.
-
Placental:
- Twin-to-twin transfusion, a rare cause of acute polyhydramnios, can occur in monochorionic twins. It is associated with oligohydramnios in the other sac and requires urgent treatment.
-
Maternal:
Twin Pregnancy Complications
- Overall perinatal mortality rate for twins is six times higher than for singletons
- Preterm delivery is the main contributing factor to the higher mortality rate
- Approximately half of all twin pregnancies deliver prematurely
- Dichorionic twin pregnancies have a 2% chance of late miscarriage
- Monochorionic twins have a 12% chance of late miscarriage
- Poor fetal growth is more common in twins
- Dichorionic twins have twice the risk of low birthweight
- 20% chance of at least one dichorionic twin suffering poor growth
- Monochorionic twins have almost double the risk of poor fetal growth compared to dichorionic twins
- Twins carry at least twice the risk of a baby with a birth defect
- Dichorionic twins have twice the risk of a structural anomaly
- Monochorionic twins have a four times higher risk of a structural anomaly
- Chromosomal abnormality risk increases with maternal age and is the same for both fetuses in monozygotic twins
- Dizygotic twins have twice the risk of chromosomal abnormality
- Monochorionic twins share vascular anastomoses, which can lead to twin-twin transfusion syndrome
Pre-Eclampsia Management
- Pre-eclampsia is the most likely diagnosis in a 24-year-old woman presenting at 36 weeks with a blood pressure of 140/100 mmHg and 3+ proteinuria
- Key risk factors for pre-eclampsia include family history of pre-eclampsia and multiple pregnancy
- Maternal assessment should include full blood count, urea and electrolytes, liver function tests, and 24-hour urine collection
- A full medical examination should be performed, including a neurological examination and abdominal palpation
- Cardiotocography (CTG) and ultrasound scan are used to assess fetal well-being
- Delivery is the treatment for pre-eclampsia
- Cervix should be assessed for favourability for induction of labour
- If the cervix is unfavourable, prostaglandin pessaries should be used for induction
- Continuous fetal monitoring is required throughout labour
- Close observation of blood pressure and urine output are necessary
- One-to-one midwifery care is required
Preterm Labour Management
- Preterm labour is defined as painful contractions occurring before 37 weeks' gestation
- Risk factors for preterm labour include twin pregnancy, uterine abnormalities, cervical damage, recurrent antepartum hemorrhage, sepsis, smoking, drug use, and lower socioeconomic class
- Diagnosis of preterm labour can be difficult due to vague symptoms
- Bleeding should always be taken seriously
- Increased analgesia requirement can be an indicator of preterm labour
- PROM (preterm rupture of membranes) is diagnosed by a sudden rush of fluid per vaginum
- Abdominal palpation may reveal uterine tenderness indicating abruption or chorioamnionitis
- Increased pulse and temperature may suggest infection
- Speculum examination assesses pooling of liquor and cervical dilation
- Maternal well-being is assessed by blood pressure, pulse, temperature, and full blood count
- High vaginal swab (HVS), fibronectin test, and nitrazine test can be performed to confirm PROM or preterm labour
- Fetal assessment includes CTG and ultrasound scan to determine liquor volume and cervical length
- Maternal steroids should be given to induce fetal lung maturity
- Tocolysis can be considered to allow time for steroid administration
- If PROM is confirmed, a 10-day course of erythromycin is started
- Intravenous antibiotics are administered during labour if HVS is positive for beta-haemolytic streptococcus
- Continuous fetal monitoring is initiated if labour continues
Diabetes in Pregnancy
- Poor glucose control in pregnancy increases the risk of congenital anomalies and miscarriage
- Good glucose control reduces these risks
- Hospital care is required in the form of a joint clinic with obstetrician, diabetic physician, nurse, and dietician
- Blood glucose levels should be monitored closely with regular blood tests and self-monitoring
- Insulin requirements increase during pregnancy
- Increased risk of diabetic ketoacidosis and hypoglycemia
- Ultrasound scan at 20 weeks' gestation is performed to check for structural anomalies
- Diabetic nephropathy and retinopathy may worsen during pregnancy but usually improve post-delivery
- Increased risk of pre-eclampsia, polyhydramnios, macrosomia, and shoulder dystocia
- Normoglycaemia is maintained during labour with a sliding scale of insulin
- Continuous fetal monitoring is required during labour
Perinatal Infections
HIV
- Caused by a RNA retrovirus
- Pregnancy does not accelerate the progression of the disease in the mother
- Pregnancy does not increase the risk of HIV progression to AIDS
- Increased risk of miscarriage, preterm delivery, and intrauterine growth restriction
- Vertical transmission occurs in 25-40% of pregnancies without intervention
- Transmission occurs around the time of delivery and during breastfeeding
- Interventions to reduce transmission include avoidance of breastfeeding, elective Caesarean section, and antiviral medication during pregnancy and in the neonatal period
Parvovirus
- Parvovirus B19 causes slap cheek syndrome in children
- Infection can be asymptomatic in 50% of children and 25% of adults
- 15% develop chronic fetal infection with persistent anemia
- Chronic fetal infection can result in non-immune hydrops
- Diagnosis is confirmed by maternal serum IgM antibodies
- Close fetal monitoring is necessary if maternal serum IgM antibodies are detected
- Parvovirus is not a teratogenic virus
Beta-Haemolytic Streptococcus
- This is an asymptomatic bacterial commensal of the gut and genital tract
- Carrier rate is approximately 20-40%
- Can cause severe neonatal infection and death
- Screening and treatment are not beneficial due to frequent recolonization
- Culture during complicated pregnancies or after previous preterm deliveries is recommended
- Intravenous antibiotics are administered during labour if the organism is present
- Premature infants, those with prolonged ruptured membranes, and growth-restricted fetuses are at higher risk
Primary Dysfunctional Labour
- Defined as slow progress in the active phase of labour, less than 1 cm per hour
- Powers, passages, and passenger are interconnected factors affecting labour progress
- Ineffective uterine action is the most common cause
- Treatments include rehydration, artificial rupture of membranes, and intravenous oxytocin
- Malpresentations can cause poor progress
- Cephalopelvic disproportion (CPD) can also cause dysfunctional labour
- Lower uterine fibroids and cervical dystocia can also lead to delayed labour
Ventouse Delivery
- Uses suction to aid delivery of the fetus
- Indications include maternal exhaustion and suspected fetal compromise in the second stage of labour
- Contraindications include face presentation, gestation less than 34 weeks, and marked bleeding from a fetal blood sample site
- Prerequisites for ventouse delivery include full dilation, station below the ischial spines, known position, good contractions, empty maternal bladder, adequate analgesia, and maternal cooperation
- Maternal complications include genital tract trauma
- Fetal complications include cephalhaematoma and rare intracranial injuries
Forceps Delivery
- Divided into non-rotational and rotational forceps
- Non-rotational forceps have similar indications as ventouse
- Indications for non-rotational forceps include face presentation, bleeding from a fetal blood sample, aftercoming head of a breech presentation, and delivery prior to 34 weeks
- Rotational forceps are used for malpresentations like occipital posterior position and deep transverse arrest
- Maternal complications include maternal trauma
- Fetal complications include rare intracranial injuries
Cord Prolapse
- Looping of umbilical cord through the cervix in front of the presenting part
- Occurs in approximately 1 in 500 deliveries
- Associated with prematurity and malpresentations
- Diagnosis is made on vaginal examination and abnormal CTG
- If the cord is through the vulva, it should be replaced and kept warm
- Urgent Caesarean section is required unless the cervix is fully dilated
- Positioning the mother on all fours with a hand pushing the presenting part upward helps to reduce cord compression
- Outcome depends on factors like gestation and other complications
Shoulder Dystocia
- Difficulty in delivering the fetal shoulder
- Incidence is 0.2 to 1.2 per cent of deliveries
- Risk factors include large fetus, small mother, maternal obesity, diabetes mellitus, prolonged first and second stages of labour, and assisted vaginal delivery
- Managed by a sequence of manoeuvres
- Initial response should be calling for senior help
- Excess traction should be avoided
- Hyperflexion and abduction of fetal legs is helpful
- Suprapubic pressure is applied to adduct fetal shoulders
- Internal rotation of fetal shoulders and delivery of the posterior arm can be required
- Debriefing is essential for the mother and partner
Postpartum Haemorrhage
- Excessive blood loss (over 500 mL) after delivery
- Primary (within 24 hours) and secondary (up to 6 weeks) haemorrhage
- Uterine atony is the most common cause
- Management includes uterine massage, bimanual compression, pharmacological agents like ergometrine and Syntocinon, and emptying the bladder
- If uterine atony persists, prostaglandin F2-alpha can be administered
- Genital tract trauma is the second most common cause
- Examination under anaesthesia is required to repair damage
- Disseminated vascular coagulation should be considered and corrected with blood products
Postpartum Pyrexia
-
Common occurrence with an incidence of approximately 5%
-
Potential causes include endometritis, wound infection, urinary tract infection, mastitis, and deep vein thrombosis
-
Investigations include blood cultures, urinalysis, cervical swabs, and imaging studies
-
Treatment depends on the underlying cause
-
Antibiotics are commonly used for infectious causes
-
Other medications may be required based on the specific diagnosis### Postnatal Pyrexia
-
Postnatal pyrexia (fever) has several common causes: urinary tract infections (UTIs), endometritis, breast engorgement/infective mastalgia, chest infections, deep vein thrombosis, and pulmonary embolism.
-
UTIs are the most common cause, presenting with dysuria, urinary frequency, and lower abdominal pain radiating to the loins.
-
UTIs are diagnosed with a clean-catch urine specimen, dipstick analysis, microscopy, and culture. A full blood count and urea/electrolytes are also recommended.
-
Endometritis presents with fever, chills, and an offensive vaginal discharge. A vaginal swab is taken, and antibiotics are administered.
-
Breast engorgement/infective mastalgia presents with breast pain, an enlarged erythematous breast, and can be treated with anti-inflammatory drugs and antibiotics. Breast abscess requires incision and drainage.
-
Chest infections, particularly in patients with underlying chest problems, present with productive cough, lung consolidation, and are treated with antibiotics, oxygen, and physiotherapy.
-
Deep vein thrombosis presents with a painful, swollen leg and calf tenderness. Examination reveals an enlarged, red, swollen, and hot calf. Doppler ultrasound confirms the diagnosis, and anticoagulants are administered.
-
Pulmonary embolism can also present with pyrexia, and a ventilation/perfusion (V/Q) scan may be necessary. Anticoagulant therapy is required.
Psychiatric Sequelae of Pregnancy
- Emotional changes are common postpartum, affecting up to 80% of women.
- Mild postnatal depression affects 7% of women, typically presenting with insomnia and difficulty coping. Counseling is considered as effective as antidepressant therapy.
- Severe postnatal depression, affecting 3-5% of women, presents with early morning wakening, altered appetite, and anhedonia. This is often diagnosed at the 6-week postnatal check using the Edinburgh Postnatal Depression Scale. Management includes reassurance, and tricyclic antidepressants are effective, showing results within 2 weeks. Treatment should continue for 6 months.
- Postpartum psychosis, occurring in 2 in 1000 women, presents as acute mania in a third of cases and depression in the remaining two-thirds. Management focuses on sedation with neuroleptic drugs, followed by assessment and admission to a mother and baby unit.
- Postpartum psychosis requires ongoing treatment with oral neuroleptic agents like haloperidol, alongside addressing extrapyramidal side effects with procyclidine. Lithium carbonate is used for manic symptoms, and electroconvulsive therapy is the first-line treatment for severe depression.
Symphysis-Fundal Height (SFH) Measurement
- SFH is measured from the top of the uterus (fundus) to the symphysis pubis to estimate gestational age and screen for complications.
- A fundal height larger than expected may indicate polyhydramnios, multiple gestations, or macrosomia.
- A fundal height smaller than expected could suggest IUGR or oligohydramnios, requiring further investigations like Doppler ultrasound.
Customized Antenatal Care
- Personalized care adapts to specific risk factors or medical conditions during pregnancy.
- Gestational diabetes mellitus (GDM) requires strict glycemic control with frequent glucose testing, insulin adjustments, HbA1c monitoring, and serial growth scans.
- Hypertensive disorders necessitate frequent blood pressure monitoring and assessment for pre-eclampsia-related complications.
Ultrasound in Obstetrics
- First trimester: Used to establish pregnancy viability, determine gestational age, detect multiple pregnancies, and screen for early anomalies like Down syndrome.
- Second trimester: Anomaly scan to detect structural anomalies, uterine artery Doppler to screen for pre-eclampsia, and cervical length assessment to predict preterm labor risk.
- Third trimester: Growth scans and Doppler studies to evaluate fetal growth, placental function, and amniotic fluid volume.
Invasive Prenatal Diagnosis
- Amniocentesis: Performed after 15 weeks for genetic testing, neural tube defect assessment, and fetal lung maturity evaluation. Risks include miscarriage, infection, and preterm labor.
- Chorionic villus sampling (CVS): Performed between 10-12 weeks gestation for earlier diagnosis compared to amniocentesis. However, it carries a higher risk of fetal loss.
- Cordocentesis: Sampling fetal blood from the umbilical vein for diagnosing infections, hemoglobinopathies, or severe anemia. It is a higher risk procedure.
Second Trimester Miscarriage
- Occurs between 12-24 weeks gestation, often due to chromosomal abnormalities, uterine anomalies, cervical incompetence, or intrauterine infections.
- Cervical incompetence leads to painless cervical dilatation and can result in premature rupture of membranes.
- Management involves cerclage for cervical incompetence, antibiotic treatment for infections, and monitoring for chorioamnionitis.
Pregnancy and Delivery
- Non-immune women should avoid contact with infectious individuals.
- All pregnant women should have Hepatitis B status determined to allow for post-delivery immunization of the baby.
- HIV testing should be offered to all pregnant women as antiretroviral drugs, elective Cesarean section, and avoidance of breastfeeding reduce vertical transmission to less than 5%.
- Dating ultrasounds should be offered to all pregnant women for accurate gestational age determination.
Second Trimester
- Triple test should be offered to all pregnant women around 15 weeks to assess Down’s syndrome risk.
Third Trimester
- Blood pressure should be monitored at all antenatal visits, particularly in the late second and early third trimester for pre-eclampsia screening.
- Urine should be analyzed at all antenatal visits for protein, blood, and glucose to detect infection, pre-eclampsia, and gestational diabetes.
Elective Cesarean Section
- Surgical procedure to deliver the baby through an incision in the abdomen and uterus.
- Indicated for breech presentations with risk factors, previous uterine surgery, placental complications, or large fetal size.
- Cesarean section reduces perinatal mortality and morbidity in breech deliveries compared to vaginal deliveries.
External Cephalic Version (ECV)
- Procedure to manually turn a breech baby into a cephalic position.
- Performed between 36-37 weeks of gestation.
- Contraindicated in cases of placenta previa, oligohydramnios, multiple pregnancies, previous Cesarean section, and pre-eclampsia.
- Risks include placental abruption, cord prolapse, transplacental hemorrhage, or fetal bradycardia.
Vaginal Breech Delivery
- Suitable for normal sized fetuses with flexed heads, multiparous women with no contraindications, and deeply engaged fetal presentation.
- Increased risk of fetal complications including birth asphyxia, injuries, and higher perinatal morbidity and mortality compared to Cesarean sections.
- Elective Cesarean section is generally recommended over vaginal breech delivery due to evidence from the Term Breech Trial unless specific criteria for vaginal delivery are met.
Twins and Higher-Order Multiple Gestations
- Monozygotic twins arise from a single fertilized ovum that splits into two.
- Chorionicity determined at the end of the first trimester.
- Dichorionic twins display a ‘lambda’ sign indicating placental tissue extension into the intertwin membrane base.
- Monochorionic twins lack the ‘lambda’ sign, and the membrane joins the uterine wall in a ‘T’ shape.
- Increased risks of intrauterine growth restriction (IUGR) in twin pregnancies, particularly in monochorionic twins.
- Twin pregnancies have a higher risk of preterm labor.
- Twin-to-Twin Transfusion Syndrome (TTTS) is a serious complication in monochorionic twins due to vascular anastomoses between the fetoplacental circulations leading to unequal growth.
- Management involves close monitoring with regular ultrasounds and Doppler studies, along with timely intervention for complications.
Disorders of Placentation: Pre-eclampsia
- Diagnosis: New-onset hypertension (BP ≥140/90 mmHg) and proteinuria (≥0.3g/24h) after 20 weeks of gestation.
- Clinical features: Headache, visual disturbances, hypereflexia, clonus, papilledema, and small for gestational age fetus.
- Complications: Eclampsia, renal failure, cerebrovascular accidents, and adult respiratory distress syndrome.
- Management: Maternal blood pressure control with antihypertensive agents; close monitoring for disease progression; fetal assessment via ultrasound and Doppler scans; delivery typically recommended after 34 weeks when maternal or fetal condition worsens.
Preterm Labor
- Defined as the onset of labor before 37 completed weeks of gestation.
- Diagnostic evaluation: clinical history; physical exam; investigations including fetal fibronectin test, transvaginal ultrasound to measure cervical length, and speculum examination for pooling of amniotic fluid.
- Management: Tocolysis with medications like nifedipine or atosiban to delay labor and allow for steroid administration for fetal lung maturation; corticosteroids (e.g., betamethasone) to promote fetal lung maturity; antibiotics for women with preterm premature rupture of membranes (PPROM) to reduce the risk of infection.
- Prognosis: The risk of neonatal complications increases with decreasing gestational age; outcomes are generally poor below 24 weeks of gestation but improve significantly after 28 weeks.
Medical Diseases in Pregnancy: Cardiac Disease
- Complicates approximately 1% of pregnancies but can lead to significant maternal and fetal morbidity and mortality.
- Common conditions: Mitral stenosis, aortic stenosis, cardiomyopathy, and congenital heart disease.
- Management: Multidisciplinary team management including cardiology, obstetrics, and anesthesiology; vaginal delivery is preferred unless contraindicated; second stage of labor should be shortened to reduce maternal cardiac strain.
HIV
- HIV is an single-stranded retrovirus that binds to CD4 receptors.
- T-helper lymphocytes, macrophages, dendritic cells and microglia cells present CD4 receptors.
- Antiretroviral drug therapy commences as highly active antiretroviral therapy if there is no evidence of immunodeficiency, this includes a combination of nucleoside reverse transcriptase inhibitors, a non-nucleoside reverse transcriptase inhibitor and a protease inhibitor.
- Treatment for immunodeficiency focuses on preventing opportunistic infection.
- Vertical transmission occurs in 25-40% of pregnancies without interventions to reduce risk.
- Interventions to reduce vertical transmission include: avoiding breastfeeding, elective Caesarean section, and the use of antiviral drugs in the later part of pregnancy and the neonatal period.
Pregnancy and Insulin
- During pregnancy, glucose crosses the placenta, but insulin does not.
- High maternal glucose levels can lead to fetal hyperglycemia.
- The fetus compensates by increasing insulin production (hyperinsulinemia).
- Insulin has growth-promoting effects, leading to potential complications:
- Macrosomia (large baby)
- Increased risk of complications during labor, such as shoulder dystocia, obstructed labor, and instrumental delivery.
- Organomegaly (enlarged organs), particularly involving the heart
- Erythropoiesis (increased red blood cell production), causing polycythemia (high red blood cell count)
- Polyhydramnios (excess amniotic fluid)
- Increased risk of preterm delivery
- Macrosomia (large baby)
- After birth, the fetus continues to have high insulin levels despite no glucose from the mother, leading to an increased risk of hypoglycemia.
- Regular feeding is vital after delivery to prevent hypoglycemia.
- Elevated insulin can hinder pulmonary phospholipid production, decreasing fetal surfactant levels.
- Surfactant is essential for reducing surface tension in alveoli and facilitating gas exchange, making newborns susceptible to transient tachypnea of the newborn.
Triple Test
- A prenatal screening test performed during the second trimester (15-20 weeks)
- Assesses risk for chromosomal conditions, such as Down syndrome, Edwards syndrome, and neural tube defects.
- Measures levels of:
- Alpha-Fetoprotein (AFP)
- Human Chorionic Gonadotropin (hCG)
- Inhibin-A
Human Chorionic Gonadotropin (hCG)
- Produced by the trophoblast, the outer layer of the developing embryo, starting from implantation.
- Levels peak around 10-12 weeks of gestation.
- Maintains the corpus luteum during early pregnancy to support progesterone production, crucial for maintaining the endometrium.
Human Placental Lactogen (hPL)
- A pregnancy-specific hormone with thyrotrophic activity.
- Secreted by the syncytiotrophoblast cells of the placenta.
- Modulates maternal and fetal metabolism.
Fetal Heart Development
-
Patent Foramen Ovale
- Opening in the intra-atrial septum that allows blood to bypass the fetal lungs.
- Usually closes shortly after birth when the baby breathes.
-
Umbilical Vein
- Carries oxygenated blood from the placenta to the fetus.
- After birth, it becomes the ligamentum teres (round ligament of the liver), part of the falciform ligament.
-
Ductus Venosus
- Shunts blood away from the liver, allowing oxygen-rich blood to reach the heart and brain more quickly.
Antenatal Care
- Full blood count to screen for anemia and thrombocytopenia.
- Blood group and red blood cell antibodies.
- Rhesus-negative women receive prophylactic anti-D at 28 and 32 weeks of gestation.
- Maternal blood screening for hepatitis B, HIV, and syphilis.
- Treatment is initiated for positive results.
- HIV: Antiviral drugs and Caesarean section.
- Syphilis: High-dose maternal antibiotics.
- Fetus is actively and passively immunized at birth for recent or carrier infections.
Antenatal Visit Examinations
- Blood pressure checks for pre-eclampsia.
- Abdominal palpation to confirm fetal presentation.
- Symphysis-fundal height measurement for fetal growth assessment.
Customized Antenatal Care
- Women with risk factors exceeding standard services receive customized care.
- Dedicated clinics for conditions like diabetes ensure specialized management.
Ultrasound in Obstetrics
-
First Trimester
- Confirms viability, accurate dating, diagnosis of twin pregnancies.
- Determines chorionicity in twins, uterine abnormalities, and ovarian cysts.
- Nuchal translucency screening.
-
Second Trimester
- Anomaly scan at approximately 20 weeks for detailed fetal structure assessment.
- Uterine artery Doppler scans for pre-eclampsia risk evaluation.
- Cervical length assessment for preterm labor risk.
- Monochorionic twins assessment for twin-twin transfusion syndrome.
-
Third Trimester
- Accurate placental site determination.
- Fetal well-being assessment by measuring fetal growth parameters, amniotic fluid volume, and umbilical artery Doppler measurements.
Invasive Prenatal Diagnosis
-
Amniocentesis
- Most common diagnostic test, performed from 15 weeks to term.
- Indicated for pregnancies with increased risk due to prior screening or history.
- Performed transabdominally with a needle.
- Fetal loss rate: 0.5-1.5%.
-
Chorionic Villus Sampling (CVS)
- Alternative to amniocentesis.
- Performed transabdominally or transvaginally from 10 weeks to term.
- Similar fetal loss rate to amniocentesis.
- Disadvantage: Potential contamination of the sample by maternal cells or placental mosaicism, leading to false-negative results or interpretation difficulties.
-
Cordocentesis
- Direct fetal blood sampling from the umbilical vein.
- Typically performed at or after 20 weeks' gestation.
Second Trimester Miscarriage
-
Pregnancy loss between 12 and 24 weeks.
-
Causes:
- 12-15 weeks: Predominantly same causes as first-trimester loss: fetal chromosomal and structural anomalies.
- Iatrogenic: Mid-trimester amniocentesis (risk of miscarriage: 1 in 200).
-
19-23 weeks: Primarily linked to preterm labor.
- Uterine overdistension (multiple pregnancy or polyhydramnios) increases myometrial contractility and cervical shortening.
- Intrauterine bleeding stimulates contractions, membrane damage, and early rupture.
- Ascending vaginal infection can trigger prostaglandin release and uterine contractions.
- Cervical weakness, due to previous surgery or congenital defects, can lead to premature cervical shortening and opening, membrane prolapse, and damage.
Polyhydramnios
-
Excess amniotic fluid.
-
Causes:
-
Maternal:
- Poorly controlled diabetes mellitus.
- Maternal red cell antibodies, suggesting isoimmunization.
-
Fetal:
- Neuromuscular conditions that impede fetal swallowing of amniotic fluid.
- Fetal gastrointestinal abnormalities (e.g., esophageal or duodenal atresia).
- Fetal hydrops, indicating cardiac failure or anemia.
- Twin-Twin Transfusion Syndrome: Rare cause in monochorionic twins, leading to urgent amniodrainage.
-
Maternal:
Biophysical Profile
- A combination of ultrasound and cardiotocography (CTG) to assess fetal well-being.
- Includes:
- Fetal breathing
- Gross body movements
- Fetal tone
- Reactive fetal heart rate
- Amniotic fluid volume
Fetal Heart Rate Patterns
-
Baseline Variability
- Reflection of the interplay between the fetal sympathetic and parasympathetic nervous systems on a CTG.
- Adequate variability indicates a well-oxygenated and neurologically intact fetus.
-
Variable Decelerations
- Abrupt decreases in fetal heart rate (at least 15 beats per minute) lasting at least 15 seconds.
- Usually caused by umbilical cord compression.
-
Fetal Heart Rate Accelerations
- Transient increases in fetal heart rate (at least 15 beats per minute) lasting at least 15 seconds.
- Often occur in response to fetal movements or contractions.
- Indicate fetal well-being.
Prenatal Diagnosis
-
Spina Bifida
- May be suspected on ultrasound by the "lemon" and "banana" signs.
- "Lemon" sign: Characteristic fetal skull shape.
- "Banana" sign: Cerebellum shape due to neural tube defects.
-
Down Syndrome
- Maternal serum hormone measurement during the second trimester (triple or quadruple test).
-
Fragile X Syndrome
- Diagnosis involves demonstrating multiple repeats (>200) on the FMR1 gene in a male fetus.
- Amniocentesis or chorionic villus sampling (CVS).
-
Klinefelter's Syndrome (47,XXY)
- Affected individuals are infertile males with:
- Slightly reduced intelligence.
- Testicular dysgenesis.
- Tall stature.
- Affected individuals are infertile males with:
Twins and Higher Order Multiple Gestations
- The overall perinatal mortality rate for twins is six times higher than for singletons.
- Preterm delivery is the main contributing factor to this higher perinatal mortality rate.
- Approximately half of all twin pregnancies deliver prematurely.
- The chance of late miscarriage is higher in monochorionic twins (12%) compared to dichorionic twins (2%).
- In dichorionic twins, each fetus has twice the risk of a low birth weight, and there is a 20% chance of at least one twin experiencing poor growth.
- Monochorionic twins have almost double the risk of poor fetal growth compared to dichorionic twins.
- Twins have at least twice the risk of a birth defect compared to singleton pregnancies.
- Dichorionic twins have at least twice the risk of a structural anomaly.
- Monochorionic twins have four times higher risk of a structural anomaly compared to dichorionic twins.
- Chromosomal abnormality risk increases with maternal age, independent of the number of fetuses.
- The risk is the same for monozygotic twins as both fetuses arise from the same egg.
- Dizygotic twins have twice the risk as the fetuses come from two different eggs.
- All monochorionic twins share vascular anastomoses, and an imbalance in blood flow across these anastomoses can cause twin-twin transfusion syndrome.
Disorders of Placentation
- A detailed examination of the placenta may reveal a chorioangioma.
Preterm Labour
- The likely differential diagnosis for a 27-year-old woman, 30 weeks gestation, presenting with painful contractions is preterm labor, with or without membrane rupture.
- Common risk factors for both preterm labor and preterm rupture of membranes (PROM) include twin pregnancy, uterine abnormalities, cervical damage, recurrent antepartum hemorrhage, and sepsis.
- Smoking, drug use, and lower socioeconomic status are social risk factors associated with increased risk of preterm labor.
- Increased analgesia requirement can help refine the diagnosis of preterm labor.
- A sudden rush of fluid per vaginum is a reliable diagnostic feature of PROM.
- Abdominal palpation may reveal uterine tenderness, suggesting abruption or chorioamnionitis.
- Infection can lead to an increased pulse and temperature.
- A positive fibronectin test increases the probability of preterm delivery.
- A positive nitrazine test increases the probability of PROM.
- Fetal tachycardia, indicative of infection, can be identified by cardiotocography (CTG).
- Ultrasound can determine liquor volume and cervical length.
- Maternal steroids should be given to induce fetal lung maturity.
- Tocolysis may be considered to allow the administration of maternal steroids.
- A 10-day course of erythromycin should be commenced if PROM is confirmed.
- Intravenous antibiotics should be administered during labor if the high vaginal swab (HVS) is positive for beta-hemolytic streptococcus.
- Continuous fetal monitoring should be initiated if labor continues.
Medical Diseases of Pregnancy
- Poor glucose control in pregnancy increases the risk of congenital anomalies and miscarriage.
- With good control, these risks are substantially reduced.
- Insulin-dependent diabetic women planning a family will require hospital care in a joint clinic with an obstetrician, diabetic physician, diabetic nurses, and dieticians.
- The aim of treatment is to maintain blood glucose levels as near normal as possible.
- Insulin requirements increase during pregnancy and need careful monitoring.
- Diabetics should monitor their own blood glucose levels and have blood taken for hemoglobin A1c to monitor long-term control.
- They are at an increased risk of both diabetic ketoacidosis and hypoglycemia and should be educated about the signs and symptoms of both.
- An ultrasound scan at approximately 20 weeks' gestation should be performed to examine for structural anomalies, particularly cardiac and neural tube defects.
- Diabetic nephropathy and retinopathy may worsen with pregnancy but usually improve post-delivery.
- There is an increased risk of pre-eclampsia, which will require regular monitoring of blood pressure and urine.
- There is an increased risk of polyhydramnios, which is associated with an increase in premature delivery.
- Poor control is associated with macrosomia and an increased rate of shoulder dystocia.
- The unexplained stillbirth rate is increased after 36 weeks, requiring careful fetal monitoring.
- During labor, normoglycaemia should be maintained using a sliding scale of insulin, and blood glucose should be tested hourly.
- Continuous fetal monitoring is required during labor due to the increased risk of the pregnancy.
Perinatal Infections
- HIV is caused by a RNA retrovirus.
- There is no evidence that pregnancy causes progression of the disease in the mother.
- There is no evidence that pregnancy increases the risk of progression from HIV to AIDS.
- HIV increases the risk of miscarriage, preterm delivery, and intrauterine growth restriction.
- Vertical transmission occurs in 25–40% of pregnancies without intervention.
- The majority of transmission occurs around the time of delivery and subsequent breastfeeding.
- Three interventions have been shown to reduce vertical transmission rates: avoiding breastfeeding, elective Cesarean section, and antiviral medication during the later half of pregnancy and into the neonatal period.
- Parvovirus B19 is the cause of slap cheek syndrome in children.
- The infection is asymptomatic in 50% of children and 25% of adults.
- Approximately 15% of infections occurring during pregnancy lead to chronic fetal infection.
- Chronic fetal infection can cause persistent anemia in utero, potentially developing into non-immune hydrops.
- Non-immune hydrops may resolve spontaneously or require blood transfusion.
- Diagnosis of primary parvovirus is confirmed by demonstrating virus-specific IgM in maternal serum.
- If IgM is detected in the maternal serum, the fetus needs close monitoring for signs of hydrops.
- Parvovirus is not a teratogenic virus.
- Beta-hemolytic streptococcus is an asymptomatic bacterial commensal of the gut and genital tract.
- It is carried asymptomatically in approximately 20–40% of women.
- It can cause severe neonatal infection and death.
- Screening and treatment are not beneficial for beta-hemolytic streptococcus due to frequent recolonization post-treatment.
- The organism should be sought by culture in complicated pregnancies or where there has been a previous preterm delivery.
- Intravenous antibiotics should be administered during labor if the organism is present or was present in a previous pregnancy.
- Premature infants, those with prolonged rupture of membranes, and growth-restricted fetuses are at the highest risk of beta-hemolytic streptococcus infection.
Labour
- Primary dysfunctional labour is defined as poor progress, less than 1 cm per hour, in the active phase of labour.
- The progress of labour depends on three interconnected variables: the powers, the passages, and the passenger.
- Ineffective uterine action, more common in primiparous women, is the most common cause of poor progress.
- Treatment modalities for ineffective uterine action include rehydration, artificial rupture of fetal membranes, and intravenous oxytocin.
- Malpresentations of the passenger, such as a brow or breech presentation, can result in slow progress.
- Cephalopelvic disproportion (CPD) is another cause of primary dysfunctional labour, implying anatomical disproportion between the fetal head and the pelvis.
- CPD can be due to a large head, a small pelvis, or a combination of both.
- CPD should be suspected if labor progresses slowly despite oxytocin, the fetal head fails to engage, vaginal examination shows severe moulding and caput, and the head is poorly applied to the cervix.
- Oxytocin may overcome the relative CPD of an abnormal presentation, such as brow, but Caesarean section may be the only recourse if the fetus is in a favorable position.
- Abnormalities of the uterus and cervix, such as an unsuspected lower uterine fibroid or cervical dystocia, can also result in delayed labor.
Operative Interventions in Obstetrics
- Ventouse is an instrument that utilizes suction to aid the delivery of the fetus.
- It can be used for both maternal and fetal indications.
- The main maternal indication is exhaustion after prolonged pushing in the second stage.
- Ventouse may be used when shortening of the second stage is an advantage, such with maternal cardiac disease.
- The main fetal indication is suspected fetal compromise in the second stage.
- Contraindications to ventouse use include face presentation, gestation less than 34 weeks, and marked bleeding from a fetal blood sample site.
- Prerequisites for delivery with the ventouse include fully dilated cervix, station below the ischial spines, known position, good contractions, empty maternal bladder, adequate analgesia, and maternal cooperation.
- The commonest maternal complication is genital tract trauma.
- The main fetal complications are cephalhematoma and, rarely, serious intracranial injuries.
- Obstetric forceps can be divided into two distinct groups: non-rotational or rotational forceps.
- Non-rotational forceps have similar maternal and fetal indications to the ventouse.
- Non-rotational forceps have both a cephalic and a pelvic curve.
- Specific indications for forceps include face presentation, bleeding from a fetal blood sample, the aftercoming head of a breech presentation, and delivery prior to 34 completed weeks.
- Obstetric forceps can also be utilized to aid delivery of the fetal head at Cesarean section.
- Kjelland's (rotational) forceps lack the pelvic curve, allowing their rotation within the pelvis.
- Rotational forceps have additional indications for malpresentations, such as an occipital posterior position or deep transverse arrest.
- The commonest maternal complication is maternal trauma.
- Forceps are less likely to cause cephalhematoma but may cause rare, serious intracranial injuries.
Obstetric Emergencies
- Cord prolapse is defined as a loop or loops of umbilical cord that fall through the cervix in front of the presenting part.
- Cord prolapse is associated with prematurity and malpresentations.
- The diagnosis is usually made on vaginal examination due to an abnormal CTG.
- Urgent Cesarean section is required unless the cervix is fully dilated, and assisted delivery can be performed safely.
- The umbilical vein should be reduced to allow oxygen to pass to the fetus by placing the mother on all fours in a 'head down' position and pushing the presenting part up with a hand in the vagina.
- Outcome depends on many factors including gestation and other pregnancy complications.
- Shoulder dystocia is defined as difficulty in delivery of the fetal shoulder.
- Risk factors for shoulder dystocia include large fetus, small mother, maternal obesity, diabetes mellitus, prolonged first stage of labor, prolonged second stage of labor, and assisted vaginal delivery.
- Shoulder dystocia is managed by a sequence of maneuvers designed to facilitate delivery without fetal damage.
- The initial response to shoulder dystocia should be a call for senior help.
- Excess traction should be avoided at all times.
- Legs should be hyperflexed and abducted at the hips.
- Suprapubic pressure should be applied to adduct the fetal shoulders.
- More complex maneuvers, involving internal rotation of the fetal shoulders and delivery of the posterior arm, are required if suprapubic pressure fails.
- Following delivery, the mother and her partner need to be debriefed regarding the events surrounding the delivery.
- Postpartum hemorrhage (PPH) is defined as excess blood loss ( > 500 mL) after delivery.
- PPH can be further subdivided into primary (within the first 24 hours) and secondary (up to 6 weeks) PPH.
- Uterine atony is the most common cause of massive blood loss.
- The first step to stop bleeding is uterine massage or bimanual compression.
- Uterine contraction can then be maintained pharmacologically using ergometrine and high-dose Syntocinon.
- The bladder should be emptied to aid contraction.
- If the uterus still fails to respond, prostaglandin F2-alpha can be administered systemically or directly into the myometrium.
- Genital tract trauma is the next most common cause of PPH if bleeding persists despite adequate uterine contraction.
- The patient will require an examination under anesthesia to explore the genital tract and repair the damage sustained.
- If bleeding persists, clotting should be checked urgently as disseminated vascular coagulation may be present and needs to be corrected with blood products.
The Puerperium
- Postpartum pyrexia is a common occurrence, with an incidence of approximately 5%.
Postnatal Pyrexia
- Most common cause: Urinary tract infection
- UTI Symptoms: Dysuria, frequency, lower abdominal pain (localized over bladder, may radiate to the loins)
- UTI Investigations: Clean-catch urine specimen (dipstix analysis for protein and nitrates), microscopy and culture, full blood count, urea and electrolytes
- UTI Treatment: Antibiotic therapy, adjust based on urine culture results
Other Common Infections
- Endometritis: Fever, rigors, offensive vaginal discharge, treat with a vaginal swab and antibiotics
- Breast Engorgement/Infective Mastalgia: Breast pain, enlarged erythematous breast, treat with anti-inflammatory drugs and antibiotics
- If breast abscess is present, requires incision and drainage
Other Causes of Postnatal Pyrexia
- Chest infection: Productive cough, consolidation at lung bases, treat with antibiotics, oxygen therapy, and physiotherapy
- Deep Vein Thrombosis: Painful swollen leg, calf tenderness, treat with anticoagulants
- Pulmonary Embolism: Pyrexia, investigate with ventilation/perfusion (V/Q) scan, treat with anticoagulants
Psychiatric Sequelae of Pregnancy
- 80% of women experience some form of emotional alteration in the postnatal period, commonly between days 3 and 10
- Mild Postnatal Depression: Affects 7% of women, gradual onset of insomnia, difficulty coping, effectively treated with counselling (as effective as antidepressant therapy)
- Severe Postnatal Depression: Affects 3-5% of women, detected at 6-week check with the Edinburgh Postnatal Score, 30% present within the first 3 months after delivery, symptoms include early morning wakening, appetite changes, ahedonia, treat with explanation, reassurance, tricyclic antidepressants (results within 2 weeks, maintain for 6 months)
- Postpartum Psychosis: Affects 2 in 1000 women, 1/3 present with acute mania, 2/3 with depression, treat with sedation (neuropleptic drugs), assessment, and admission to a mother and baby unit, long-term management by a psychiatrist, oral neuroleptic agents, procyclidine for extrapyramidal side effects, lithium carbonate for mania, electroconvulsive therapy (ECT) for severe depression, continue treatment for at least 6 months (50% recurrence rate)
Symphysis-Fundal Height (SFH) Measurement
- Definition: Distance from the top of the uterus (fundus) to the symphysis pubis
- Purpose: Estimates gestational age, screens for IUGR (intrauterine growth restriction) and polyhydramnios
- Interpretation:
- Fundal height larger than expected: Suggests polyhydramnios, multiple gestations, or macrosomia
- Fundal height smaller than expected: Suggests IUGR or oligohydramnios, requires further investigation (Doppler ultrasound for placental insufficiency)
Customized Antenatal Care
- Definition: Tailored antenatal care for specific risk factors/conditions that complicate pregnancy
- Clinical Application: Required for high-risk conditions like gestational diabetes mellitus (GDM), hypertensive disorders, or autoimmune diseases
- Diabetes-Specific Care:
- Strict glycemic control to prevent fetal complications (macrosomia, congenital anomalies, neonatal hypoglycemia)
- Frequent glucose testing, insulin therapy adjustments, HbA1c monitoring, serial growth scans
- Hypertensive Disorders:
- Frequent blood pressure monitoring, assessment for pre-eclampsia complications (proteinuria)
- Customized care ensures close monitoring, reducing adverse outcomes and allowing for early intervention
Ultrasound in Obstetrics
- First Trimester:
- Establish pregnancy viability, determine gestational age, detect multiple pregnancies
- Early screening for anomalies: Nuchal translucency measurement + maternal serum markers for chromosomal anomalies (Down syndrome)
- Detecting chorionicity in twins: Important for anticipating complications (twin-twin transfusion syndrome)
- Second Trimester:
- Anomaly Scan: Detailed ultrasound for structural anomalies
- Uterine artery Doppler: Screens for increased risk of pre-eclampsia by assessing uterine artery resistance
- Cervical length assessment: Predicts risk of preterm labor, especially in women with a history of cervical incompetence or prior preterm deliveries
- Third Trimester:
- Growth scans and Doppler studies: Evaluate fetal growth, placental function, and amniotic fluid volume
- Biophysical profile and umbilical artery Doppler: Assess fetal well-being, predict fetal hypoxia or acidosis
Techniques for Invasive Prenatal Diagnosis
- Amniocentesis: Performed after 15 weeks for genetic testing, neural tube defects, fetal lung maturity in cases of preterm labor
- Complications: Miscarriage (0.5-1.5%), infection, preterm labor
- Diagnostic Yield: Karyotyping, biochemical testing (trisomy 21), alpha-fetoprotein (AFP) levels for neural tube defects
- Chorionic Villus Sampling (CVS): Performed between 10-12 weeks
- Advantage: Earlier diagnosis than amniocentesis
- Risks: Higher rate of fetal loss, contamination by maternal cells or placental mosaicism
- Cordocentesis: Sampling fetal blood from umbilical vein, used for diagnosing fetal infections, hemoglobinopathies, or severe anemia
- Complications: Higher risk procedure, reserved for situations where other techniques are not diagnostic
Second Trimester Miscarriage
- Definition: Loss of pregnancy between 12 and 24 weeks gestation
- Pathophysiology:
- Chromosomal abnormalities (common), uterine anomalies, cervical incompetence, intrauterine infections
- Cervical incompetence leads to painless cervical dilatation, premature rupture of membranes
- Management:
- Cerclage: Used for cervical incompetence
- Infection Management: Antibiotics and monitoring for signs of chorioamnionitis
Cervical Cerclage
- Definition: Surgical procedure used to place a suture around the cervix to prevent/treat cervical incompetence (prevents premature opening of the cervix causing miscarriage or preterm labor)
- Indications: History-Indicated
- Two or more consecutive second-trimester miscarriages due to painless cervical dilatation
- Preterm birth (before 34 weeks) due to painless cervical dilatation or cervical insufficiency
- Indications: Ultrasound-Indicated
- Shortened cervical length (1–2 cm) in the second trimester, often accompanied by bulging amniotic membranes
- Grades:
- McDonald Cerclage: Most common, purse-string suture around cervix at the cervicovaginal junction, less invasive, easily removed at 36-37 weeks or at labor onset
- Shirodkar Cerclage: Deeper placement of the suture, requires dissection of vaginal mucosa, more robust support for the cervix but technically more challenging
- Transabdominal Cerclage: Performed when transvaginal is not feasible, placed laparoscopically or via laparotomy, requires Cesarean delivery for subsequent births
- Procedure Steps:
- Anesthesia: Regional (spinal/epidural), general if needed
- Positioning: Lithotomy position, cervix visualized with speculum
- Cervical Preparation: Cervix grasped with forceps, vaginal mucosa cleansed
- Suture Placement:
- McDonald: Purse-string suture placed circumferentially around cervix at the cervicovaginal junction, tied anteriorly
- Shirodkar: Transverse incision in anterior vaginal mucosa, suture placed at internal os, tied anteriorly or posteriorly
- Transabdominal: Laparoscopically or via laparotomy, suture placed at internal cervical os
- Closure and Confirmation: Mucosal incision closed for Shirodkar, cerclage confirmed to be secure
- Postoperative Care: Monitor for infection, contractions, premature rupture of membranes (PROM), bed rest may be advised, serial ultrasounds to monitor length and suture integrity
- Removal: McDonald and Shirodkar removed at 36-37 weeks or earlier if labor starts, Transabdominal may remain in place
Perinatal Mortality Rate
- Definition: Number of stillbirths and early neonatal deaths per 1000 live births and stillbirths
Fetal and Neonatal Deaths
- Causes: Any three of the following:
- Congenital Anomaly
- Severe Immaturity
- Infection
- Intracranial Haemorrhage
- Isoimmunization
- Unknown
Preterm Infant Management
- Antenatal Steroids: Reduce the risk and severity of respiratory distress syndrome
- Surfactant: Administered if antenatal steroids were not given, to reduce the severity of respiratory distress syndrome
- Hypothermia: Large surface area, lack of subcutaneous fat, and keratinized skin predispose to hypothermia and dehydration, treated with an incubator
- Jaundice: Common due to liver immaturity, treated with phototherapy
- Periventricular Haemorrhage and Intraventricular Haemorrhage: Can lead to cerebral palsy
Routine Antenatal Screening Tests
- Full Blood Count: Screen for anaemia and thrombocytopenia
- Maternal Blood Group: Determines blood group for cross-matching later
- Rhesus Status: Determines rhesus status, prophylaxis offered at 28 and 34 weeks if mother is rhesus negative
- Rubella Status: Determines rubella status, vertical transmission carries risk of congenital abnormalities, especially in the first trimester
Conception, Implantation, and Embryology
- Oocyte structure: Consists of an oocyte, zona pellucida, granulosa cells, and follicular fluid
- Meiosis: Begins with diploid cells, two divisions result in haploid daughter cells (no DNA replication in the second division)
- Confirmation of pregnancy: Missed period, pregnancy tests (detect human chorionic gonadotrophin), transvaginal ultrasound
Physiological Changes in Pregnancy
- Cardiovascular Changes: 10-20% increase in heart rate, 10% increase in stroke volume, 30-50% increase in cardiac output, decrease in maternal mean arterial pressure and peripheral vascular resistance
- hCG: Hormone levels rise dramatically in the first 10 weeks, plateau after 12 weeks, maintains corpus luteum function and progesterone production
- Prolactin: Concentrations increase throughout pregnancy, oestrogen antagonizes its lactation promoting effects, rapid fall in oestrogen after birth allows lactation to occur, sucking promotes lactation by increasing oxytocin and prolactin release
Fetal Development
- Cardiovascular System at Birth: Extensive remodelling due to changed haemodynamics of the activated pulmonary system, closure of ductus venosus, foramen ovale, and ductus arteriosus
- Lung Fluid Reabsorption: Compression at delivery removes 1/3 of the fluid, adrenalin promotes reabsorption, surfactant release triggered by adrenalin and steroids, fall in capillary pressure with alveoli expansion, respiratory movements begin
- Preterm Infant Complications: Respiratory distress syndrome (treated with antenatal steroids), hypothermia (treated with an incubator), jaundice (treated with phototherapy), periventricular/intraventricular haemorrhage (can lead to cerebral palsy)
Hepatitis B in Pregnancy
- Women who are not immune should avoid infectious contacts
- Offer Hepatitis B status determination and immunization for the baby after birth
HIV in Pregnancy
- All women should be offered HIV testing
- Antiretroviral agents, elective Caesarean section, and avoidance of breastfeeding reduce vertical transmission to less than 5%
Prenatal Screening
- Dating ultrasound is offered to all women for accurate dating
Second Trimester Screening
- Triple Test is offered to all women around 15 weeks
- It indicates the risk of Down’s syndrome
Third Trimester Monitoring
- Blood pressure is measured at each prenatal visit, mainly during the late second and early third trimester as a screening test for preeclampsia
- Urine is analyzed at each prenatal visit for protein, blood, and glucose, used to detect infection, pre-eclampsia, and gestational diabetes
Elective Caesarean Section
- Surgical procedure for delivering the baby via an incision in the abdomen and uterus
- Commonly recommended for breech presentations, especially with risk factors
- Indications: previous uterine surgery, placental complications, or large fetal size
- Evidence: The Term Breech Trial demonstrated that Caesarean reduces perinatal mortality and morbidity in breech deliveries compared to vaginal deliveries
External Cephalic Version (ECV)
- Procedure to turn a breech baby into a cephalic position manually
- Performed between 36–37 weeks of gestation
- Contraindications: Placenta previa, oligohydramnios, multiple pregnancies, prior Caesarean section, and pre-eclampsia.
- Risks: placental abruption, cord prolapse, transplacental hemorrhage, or fetal bradycardia
Vaginal Breech Delivery
- Suitable for normal-sized fetus with flexed head, multiparous woman with no contraindications and deeply engaged presentation
- Risks: Increased risk of fetal complications, such as birth asphyxia, injury to the baby, and higher perinatal morbidity and mortality compared to elective Caesarean sections
Clinical Recommendations Breech Delivery
- Elective Caesarean section is recommended over vaginal breech delivery in most settings unless very specific criteria are met that favor a vaginal delivery
Monozygotic Twins
- Arise from a single fertilized ovum that splits into two.
- The timing of the split determines chorionicity and amnionicity
- Chorionicity determination is best done at the end of the first trimester.
- Dichorionic twins have a ‘lambda’ sign, indicating placental tissue extension.
- Monochorionic twins lack this sign, and the membrane joins the uterine wall in a ‘T’ shape.
Risks and Complications of Twin Pregnancies
- Increased risk of intrauterine growth restriction (IUGR), particularly in monochorionic twins
- Higher risk of preterm labor, leading to increased perinatal morbidity and mortality
- Twin-to-Twin Transfusion Syndrome (TTTS) is a serious complication in monochorionic twins due to vascular anastomoses between the fetoplacental circulations, leading to volume imbalance and growth discrepancies
Management of Twin Pregnancies
- Close monitoring with regular ultrasound to assess growth, fluid volume, and Doppler studies, along with timely intervention when complications arise
Pre-eclampsia
- Defined by new-onset hypertension (BP ≥140/90 mmHg) and proteinuria (≥0.3g/24h) after 20 weeks of gestation.
Clinical Features of Pre-eclampsia
- Headache, visual disturbances, hypereflexia, clonus, papilledema, and small for gestational age fetus.
Complications of Pre-eclampsia
- Eclampsia, renal failure, cerebrovascular accidents, and adult respiratory distress syndrome
Management of Pre-eclampsia
- Maternal Assessment: Blood pressure control with antihypertensive agents such as labetalol. Close monitoring for signs of disease progression.
- Fetal Assessment: Regular ultrasound to monitor fetal growth and amniotic fluid volume, along with Doppler scans for fetal wellbeing.
- Delivery: Recommended when the maternal or fetal condition worsens, typically after 34 weeks gestation.
Preterm Labor
- Defined as the onset of labor before 37 completed weeks of gestation.
Diagnostic Evaluation of Preterm Labor
- Clinical History & Physical Exam: Check for risk factors such as multiple gestations, uterine anomalies, or a history of preterm delivery.
- Investigations: Fetal fibronectin test, transvaginal ultrasound to measure cervical length, and speculum examination for pooling of amniotic fluid to diagnose preterm rupture of membranes.
Management Preterm Labor
- Tocolysis: Medications like nifedipine or atosiban to delay labor and allow for steroid administration for fetal lung maturation.
- Steroids: Administer corticosteroids (e.g., betamethasone) to promote fetal lung maturity.
- Antibiotics: For women with preterm premature rupture of membranes (PPROM) to reduce the risk of intra-amniotic infection and neonatal sepsis.
Prognosis of Preterm Labor
- The risk of neonatal complications increases with decreasing gestational age.
- Outcomes are generally poor below 24 weeks of gestation but improve significantly after 28 weeks.
Cardiac Disease in Pregnancy
- Complicates approximately 1% of pregnancies but can lead to significant maternal and fetal morbidity and mortality.
- Common Conditions: Mitral stenosis, aortic stenosis, cardiomyopathy, and congenital heart disease.
Management of Cardiac Disease in Pregnancy
- Prenatal Care: Involves multidisciplinary team management, including cardiology, obstetrics, and anesthesiology.
- Delivery Planning: Vaginal delivery is preferred unless contraindicated. The second stage of labor should be shortened to reduce maternal cardiac strain.
- Pharmacological Management: Beta-blockers, such as labetalol, can be used, but drugs such as ACE inhibitors are contraindicated due to fetal risks.
HIV Infection
- HIV is an single-stranded retrovirus that binds to CD4 receptors.
- T-helper lymphocytes, macrophages, dendritic cells, and microglia cells present CD4 receptors.
- Two main treatment strategies:
- If there is no evidence of immunodeficiency, antiretroviral drug therapy is commenced as highly active retroviral therapy, a combination including nucleoside reverse transcriptase inhibitors, a non-nucleoside reverse transcriptase inhibitor, and a protease inhibitor.
- If there is evidence of immunodeficiency, then treatment is aimed at preventing opportunistic infection.
- Vertical transmission occurs in 25–40 per cent of pregnancies if there are no interventions to reduce the risk.
- The three interventions that have been shown to reduce the vertical transmission of HIV are: avoiding breast feeding, elective Caesarean section, and the use of antiviral drugs in the later half of pregnancy and the neonatal period.
Macrosomia
- A condition where the fetus has an excessive birth weight, typically above the 90th percentile for gestational age or weighing more than 4,000-4,500 grams at birth.
Causes of Macrosomia
- Maternal diabetes is a primary cause, particularly when maternal blood glucose levels are not adequately controlled during pregnancy.
Pathophysiology of Macrosomia
- Increased Fetal Insulin Production:
- Hyperglycemia in the mother results in increased glucose transfer to the fetus across the placenta through facilitated diffusion.
- The fetal pancreas, which begins functioning around the 10th to 12th week of gestation, responds to this excess glucose by producing more insulin.
- Insulin acts as a potent growth hormone for the fetus, stimulating protein synthesis and the deposition of fat and glycogen, leading to increased growth and adiposity.
- Fetal Anabolic State:
- High levels of fetal insulin promote an anabolic state.
- Insulin enhances the uptake of glucose and amino acids into cells, promoting lipogenesis (formation of fats) and protein synthesis.
- This results in accelerated growth of fetal adipose tissue and muscle mass, contributing to macrosomia.
- Insulin-Like Growth Factors (IGFs) Pathway Activation:
- Hyperinsulinemia in the fetus leads to increased expression of insulin-like growth factors (IGF-1 and IGF-2), which are critical regulators of fetal growth.
- These factors stimulate cell proliferation and inhibit apoptosis, resulting in overall increased tissue mass and growth.
- Excess Nutrient Supply and Fetal Adiposity:
- Elevated maternal glucose levels not only increase the delivery of glucose but can also lead to increased free fatty acids and amino acids transfer to the fetus.
- Insulin enhances lipogenesis (conversion of carbohydrates into fat) in the fetus, leading to increased fat storage, which further contributes to macrosomia.
- Organomegaly and Adiposity:
- Macrosomic infants typically show organomegaly (enlargement of organs like the liver, heart, and adrenal glands) due to increased glycogen and fat deposition in these organs.
- The heart, in particular, may demonstrate hypertrophic changes due to the effects of insulin.
Clinical Implications of Macrosomia
- Obstetric Complications:
- Macrosomic infants are at a higher risk for complications during delivery, such as shoulder dystocia, birth injuries (e.g., brachial plexus injury), and the need for operative delivery (e.g., Caesarean section).
- Neonatal Complications:
- Macrosomic infants born to diabetic mothers are at risk for neonatal hypoglycemia due to persistent hyperinsulinemia after delivery, respiratory distress syndrome, and metabolic complications like hypocalcemia and polycythemia.
- Long-Term Risks:
- Infants exposed to hyperglycemia in utero are at increased risk for childhood obesity and metabolic syndrome later in life, which can predispose them to type 2 diabetes mellitus and cardiovascular disease.
Chorionic Villus Sampling (CVS)
- Invasive prenatal diagnostic procedure performed to obtain a sample of placental tissue (chorionic villi) to test the fetus's genetic and chromosomal health.
- Performed between the 10th and 13th weeks of gestation.
- Provides early information about the baby's genetic health.
Indications for CVS
- Advanced Maternal Age: Women aged 35 or older have a higher risk of chromosomal abnormalities.
- Previous Pregnancy with Chromosomal Abnormalities: Indicates an increased risk of genetic conditions in subsequent pregnancies.
- Family History of Genetic Disorders: Identifies individuals with a higher risk of inheriting genetic diseases.
- Positive Screening Test: Abnormal results from first-trimester screening tests or non-invasive prenatal testing (NIPT) suggest the need for further investigation.
- Parental Chromosomal Translocations: Couples with known balanced translocations or other chromosomal abnormalities have an increased risk of transmitting these conditions.
- Ultrasound Abnormalities: Structural anomalies detected in the first trimester that suggest potential genetic syndromes warrant further investigation.
Technique and Procedure of CVS
-
Transcervical Approach:
- Patient positioned in a lithotomy position.
- Speculum used to visualize the cervix.
- Thin catheter inserted through the cervix into the placenta under ultrasound guidance.
- Chorionic villi aspirated using gentle suction.
-
Transabdominal Approach:
- Abdominal area is cleaned and prepped.
- Thin needle inserted through the abdominal wall and uterus into the placenta under continuous ultrasound guidance.
- Sample aspirated.
- The choice of technique depends on placental position, maternal anatomy, and gestational age.
Sample Analysis
- Chorionic villi contain the same genetic material as the fetus.
- Karyotyping: Analysis for chromosomal abnormalities like Down syndrome (Trisomy 21), Edwards syndrome (Trisomy 18), and Patau syndrome (Trisomy 13).
- DNA Analysis: Detection of single-gene disorders such as cystic fibrosis, sickle cell anemia, and Duchenne muscular dystrophy.
- Biochemical Testing: Evaluation for inborn errors of metabolism or other genetic enzyme deficiencies.
Risks and Complications
- Miscarriage: Risk estimated at 0.5-1%, slightly higher than amniocentesis.
- Infection: Rare, but there's a risk of intrauterine infection.
- Bleeding or Amniotic Fluid Leakage: Transcervical CVS can cause vaginal bleeding.
- Limb Reduction Defects: If performed before 10 weeks gestation, there's a small risk of fetal limb abnormalities.
- False Results or Ambiguity: Maternal cell contamination or confined placental mosaicism can lead to inaccurate or ambiguous results, requiring further testing with amniocentesis.
Advantages of CVS
- Early Diagnosis: Detects genetic conditions earlier compared to amniocentesis.
- Short Turnaround Time: Results are usually available within 1–2 weeks, allowing for prompt decision-making.
Disadvantages of CVS
- Limited Information on Neural Tube Defects: Does not provide information on neural tube defects like spina bifida. A maternal serum alpha-fetoprotein (AFP) test or detailed ultrasound is recommended later in pregnancy.
- Potential for False Results: Confined placental mosaicism (where the genetic material of the placenta differs from that of the fetus) can lead to misleading results.
Clinical Considerations
- Patient Counseling: Prior to the procedure, informed consent is required, involving detailed discussion of risks, benefits, and alternatives.
- Alternative Diagnostic Options: Amniocentesis or non-invasive prenatal testing (NIPT) may be considered for women presenting after 13 weeks or those with contraindications to CVS.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on key aspects of maternal and fetal health including preterm labour, hormonal influences, and screening tests. This quiz covers critical concepts such as cervical length, the role of corticosteroids, and the effects of hyperglycaemia on the fetus. Ideal for students and professionals in the field of obstetrics and gynecology.