Fetal Well-being & Diagnostic Test Lecture 4 PDF

Fetal well-being & Diagnostic test Lecture 4 Maternity and Childhood Nursing Department  What is a Teratogen? Definition:  A teratogen is an environmental agent that can adversely affect the unborn child, thus producing a birth defe...

Fetal well-being & Diagnostic test Lecture 4 Maternity and Childhood Nursing Department  What is a Teratogen? Definition:  A teratogen is an environmental agent that can adversely affect the unborn child, thus producing a birth defect Timing The effect of The fetal brain develops teratogens depends throughout pregnancy upon the timing of and can be affected at exposure. any time. The first trimester of Exposure to a teratogen pregnancy is the during the two weeks critical period of organ following conception is and limb development unlikely to cause birth in the fetus. defects. Maternity and Childhood Nursing Department  General Risk Factors-Physical Agents X-Rays  Possible effects on the newborn include slow growth, developmental disabilities, sterility, possible cancers later in life Hyperthermia  Refers to an abnormally high body temperature (fever, prolonged exposure to extreme heat source, heavy exercising)  Maternal hyperthermia during first trimester can cause CNS defects Stress:  decreases oxygen to fetus, weakens mother’s immune system, and leads to unhealthy behaviors such as smoking or drinking alcohol Mother’s Age: neither too young, nor too old is best Maternity and Childhood Nursing Department  General Risk Factors-Physical Agents Caffeine  Caffeine passes easily form a mother to her fetus through the placenta  Caffeine can Increase fetal heart rate and movement Draw calcium from the body Interfere with absorption of iron Worsen mood swings Tobacco  Low birth rate; SIDS, Growth retardation  Premature delivery  Respiratory infections and allergies  Secondhand smoke has similar effects Maternity and Childhood Nursing Department  General Risk Factors Nutrition  A balanced diet is important to the health of a growing fetus  Increase 300 calories  supplement diet with prenatal vitamins  Excessive amounts of vitamin A - associated with cleft palate.  Inadequate maternal nutrition can lead to learning disabilities  Folic acid is a necessity to help the nervous system of the fetus develop. Without it the fetus could develop spina bifida (neural tube defect -NTD  Without proper nutrition: premature birth, underweight, nervous system problems, vulnerable to illness Maternity and Childhood Nursing Department  General Risk Factors Drugs  Over the counter: aspirin can cause hemorrhage  Prescription: check with your doctor  Alcohol: Fetal Alcohol Syndrome (FAS): brain injury, growth impairment, facial deformity, congenital heart defects, short attention spans, behavioural problems  Cocaine: pre-maturity, neonatal intoxication and withdrawal (jitteriness, excessive crying, irritable, inconsolable), cerbrovascular problems, learning disabilities, behavioural problems  Narcotics: small, withdrawal, central nervous system damage, irritability, gastrointestinal dysfunction, respiratory distress  Marijuana: small birth weight, decreased psychomotor performance, decreased ability to perform skilled tests, learning disabilities, deformities  Smoking: low birth weight, prone to infections, increased mortality, at risk for cerebral palsy, malformation and developmental disabilities, high risk of SIDS Maternity and Childhood Nursing Department  Illegal Drugs  Addiction is passed to baby  Low birth rate  Premature delivery  Risk of seizures  Sudden Infant Death Syndrome  Heart disease  Stillbirth  Stroke  Brain Damage  Developmental delays  Physical abnormalities  Death Maternity and Childhood Nursing Department  Food & Drug Administration classification (FDA) 1. Category A: Controlled studies in humans demonstrated no fetal risk. E.g.: Prenatal vitamins, KCL, Thyroxin 2. Category B: Animal studies indicate no fetal risk; no controlled studies in humans. E.g.: Penicillin, Antacids, Insulin, Ampicillin, Metronidazole. 3. Category C: Animal studies indicate fetal risk; no human studies. These drugs are administered only when their benefits outweighs the potential fetal harm. E.g., Furosemide, β-blockers, Methyldopa, Nifedipine, Heparins, Aminophylline, Gentamycin. 4. Category D: There is evidence of fetal risk in humans, but the benefits may outweigh the risk. These drugs are given only in serious disease because no alternative. E.g., Diazepam, Tetracycline, Methotrexate. 5. Category X: There is clear human risk that outweigh the benefits. These drugs are contraindicated. Estrogen, Androgens, Thalidomide (to relieve morning sickness) Maternity and Childhood Nursing Department  Genetic Assessment There are a number of techniques which are used to diagnose prenatal defects in fetuses whose mothers are at risk of having a baby with an abnormality. This may be a question of a family history of an anomaly, or that the parents have already had one child with a defect. Common techniques are: Alpha Feta Protein (AFP) Amniocentesis Chorionic villus sampling (CVS) Ultrasound (U/S) Non Stress Test (NST) Contraction Stress Test (CST) Maternity and Childhood Nursing Department ALPHA FETOPROTEIN (AFP) Genetic Screen test that measures the protein produced by fetal liver. Main protein in fetal plasma. Diffuses from fetal plasma to fetal urine, excreted in amniotic fluid. Test is taken between the 16th-20th week of pregnancy; Done with mothers' blood Increased levels produce neural tube defect Decreased levels result in Down Syndrome The normal values in males or nonpregnant females is generally less than 40 micrograms/liter It is safe and low risk Maternity and Childhood Nursing Department  AMNIOCENTESIS Aspiration of amniotic fluid for examination; Used with direct ultrasound An invasive procedure requires a consent form to be signed Cannot be done until second trimester (14-16 wks). To examine cells shed by fetus Tissue culture is checked for chromosomes, genetic defects Patient must be informed of possible complications Trauma (fetal death) Infection Hemorrhage Leakage of amniotic fluid Maternity and Childhood Nursing Department  Amniocentesis Preparation – Permits signed – Vital Signs and FHT’s – Abdominal prep and scrub Procedure – Area of insertion is anesthesized and a needle inserted into the amniotic cavity and 5 - 30 cc of fluid withdrawn for analysis Post care / Discharge Teaching – Vital signs and FHT’s normal – No leakage of fluid from site – Teach patient to report -- lack of fetal movement, discharge or bleeding, abdominal pain, or fever Maternity and Childhood Nursing Department CHORIONIC VILLI SAMPLE (CVS) Genetic studies , A small sample of chorionic villi is suctioned out of the placenta A thin tube passed through either the vagina and cervix, or a needle passed through the abdomen and uterus; Ultrasound is used to guide needle placement Advantage – can be done earlier than an amniocentesis to detect problems. Checks for Chromosomal studies (e.g: Down Syndrome) about the 10th to 12th weeks usually on women who have already had a child with defects Complications: vaginal spotting, miscarriage, ROM, chorioamnionitis If done prior to 10 weeks, increased risk of limb anomalies Because of the possibility of fetomaternal hemorrhage, women who are Rh negative should receive immune globulin (RhoGAM) to avoid isoimmunization. Maternity and Childhood Nursing Department Chorionic Villus Sampling (CVS)  A biopsy needle is inserted through the abdominal wall and guided by ultrasound A plastic catheter is inserted through the cervix and guided by ultrasound Maternity and Childhood Nursing Department  Ultrasound (U/S) Ultrasound: an instrument which uses reflective sound waves as they travel in tissue to visualize structures in the body fluid = dark; tissue = white Can be done abdominally or transvaginal Used to detect: Confirm pregnancy, Length of gestation; Placement and structure of placenta, Baby’s gender; Multiple pregnancies; Anatomical abnormalities It is a non-invasive and painless procedure Results are immediate Allows the mother and family to “see” the baby Maternity and Childhood Nursing Department  Ultrasound Nursing Care Transabdominal Ultrasound Make sure that the patient has a full bladder Place patient on back with a towel roll under one hip -- allowing better perfusion of the placenta The test requires about 20 - 30 minutes Transvaginal Ultrasound Same as above except does not need to fill bladder. Maternity and Childhood Nursing Department  Electronic Fetal Monitoring-EFHM Provides continuous data and is routine for high-risk clients Fetal Heart Rate – 110 – 160 bpm May be done externally or with an internal monitor Is there tachycardia or bradycardia? Cardiotocography (CTG): Used during pregnancy to monitor fetal heart rate and uterine contractions. It is most commonly used in the third trimester and its purpose is to monitor fetal well-being and allow early detection of fetal distress ( accelerations or decelerations (early, late, variable, prolonged) (prolonged = decrease ≥ 15 bpm for ≥ 2 min but < 10 min)? Maternity and Childhood Nursing Department  Electronic Fetal Monitoring Indications for: – Previous history of stillborn – Presence of complication – Induction of labor, preterm labor – Decreased fetal movement – Non-reassuring fetal status – Meconium staining of amniotic fluid – Trial of labor following a C-section Maternity and Childhood Nursing Department  Category 1 - Normal – FHR 110 – 160 – No late or variable decelerations – May see early decelerations Maternity and Childhood Nursing Department Nursing Interventions for Non reassuring FHR Considered when one or more than of the following (Tachycardia or bradycardia for more than 10 minutes)Optimize maternal positioning – side- lying Discontinue oxytocin if indicated Give supplemental oxygen if indicated Notify physician or midwife Administer IV fluids as needed Monitor maternal v/s for hypotension and treat Elevate HOB 30 degrees Initiate continuous monitoring Provide client and family with explanation Maternity and Childhood Nursing Department  Daily Fetal Movement Counts – Assessment of fetal activity by the mother – Non-invasive, inexpensive, simple to understand, and does not interfere with routine at home – Daily record beginning at 27 weeks gestation – Count at same time each day – 1 hour after meals – Lie in side-lying position – Contact health care provider when: < 10 movements in 2 hours using daily movement record No fetal movement in AM Fetal movements becoming slower – Since healthy babies have sleep cycles, baby may not kick, or kick less than usual, or have less than 10 kicks in 3 hours. If so, wake up the baby by drinking fluid or by walking for 5 minutes. Repeat the kick count. Maternity and Childhood Nursing Department Fetal Movement Counts (Kick Counts) The evaluation may include: –Ultrasound - taking pictures from sound waves to evaluate the growth of the baby, amniotic fluid quantity, placenta, blood flow pattern etc. –Non stress test (NST) -Baby's heart rate monitoring in response to its own movements –Contraction stress test (CST) -Baby's heart rate monitoring in response to uterine contractions Maternity and Childhood Nursing Department Non-Stress Test (NST)-Evaluation of Fetal Status Observation of fetal heart rate associated with fetal movement. With movement of the fetus, the FHR should increase, or accelerate This test is based on the knowledge that when the fetus has adequate oxygenation and an intact CNS, there are accelerations of FHR with movement. Maternity and Childhood Nursing Department  Procedure for the NST Electronic fetal monitor is applied As the NST is done, fetal movements are documented Compare the FHR with the fetal movements Results: – Reactive -- two accelerations of 15 Beats Per Minute (BPM) lasting 15 seconds, over a 20-minute period associated with fetal movement. This is an indication of fetal well-being – Nonreactive -- If the test does not meet the criteria after 40 minutes, in which case further assessments are needed with a CST Maternity and Childhood Nursing Department  Non-Stress Test Example of a nonreactive NST. There are no accelerations of FHR with FM. Baseline FHR is 130 beats per minute. The tracing of uterine activity is on the bottom of the strip. Maternity and Childhood Nursing Department  Contraction Stress Test (CST) Uterine contractions decrease uterine blood flow and placental perfusion. If this decrease is sufficient to produce hypoxia in the fetus, a deceleration in FHR will result, beginning at the peak of the contraction and persisting after its conclusion (late deceleration). – Nipple-Stimulated 10 min massage 2 min massage 5 min break – Oxitocin-Stimulated 10 U in 1000 ml fluid IV Maternity and Childhood Nursing Department  CST NEGATIVE – No late decelerations, with minimum of three uterine contractions lasting 40 to 60 sec within 10-min period POSITIVE – Persistent and consistent late decelerations occurring with more than half of contractions a positive test result indicates that fetus is at increased risk for perinatal morbidity and mortality; physician may perform vaginal birth after successful induction or may proceed directly to cesarean birth; HYPERSTIMULATION – Late decelerations occurring with excessive uterine activity (contractions more often than every 2 min or lasting longer than 90 sec) or persistent increase in uterine tone UNSATISFACTORY – Inadequate uterine contraction pattern or tracing too poor Maternity and Childhood Nursing Department  Contraction Stress Test (CST) Example of a positive contraction stress test (CST). Repetitive late decelerations occur with each contraction. Note that there are no accelerations of FHR with three fetal movements (FM). The baseline FHR is 120 beats per minute. Uterine contractions (bottom half of the strip) occurred four times in 12 minutes. Maternity and Childhood Nursing Department Any Questions Maternity and Childhood Nursing Department