Assessment of Fetal Well-being PDF

Assessment of fetal well being 1 DR MOATH SALEH BANI HANI 2 INTRODUCTION  ANTENATAL FETAL SURVEILLANCE IS ASSESSMENT OF FETAL WELL BEING IN ANTEPARTUM PERIOD TO ENSURE DELIVERY OF HEALTHY NEONATE. Two main objectives are:-  Early detection of fetuses at risk to prevent perinatal m...

Assessment of fetal well being 1 DR MOATH SALEH BANI HANI 2 INTRODUCTION  ANTENATAL FETAL SURVEILLANCE IS ASSESSMENT OF FETAL WELL BEING IN ANTEPARTUM PERIOD TO ENSURE DELIVERY OF HEALTHY NEONATE. Two main objectives are:-  Early detection of fetuses at risk to prevent perinatal mortality and morbidity.  Find out normal fetuses and avoid unwarranted interventions. 3 ANTEPARTUM FETAL ASSESSMENT METHODS:- 1 a CLINICAL ASSESSMENT  Weight gain  Fundal height  Abdominal girth  Auscultation of fetal heart b fetal movement count by mother( kick chart) 2.Ultrasound for fetal parameters 3.NST (non-stress test ) 4.biophysical profile (BPP) 5.Doppler 4 INDICATIONS  MATERNAL  FETAL  PREGNANCY RELATED MATERNAL  Hypertension  Diabetes  Heart disease  Chronic renal disease  Severe anemia  Acute illnesses 5 Fetal  Fetal growth restriction (IUGR)  Rh isoimmunisation  Fetal cardiac arrhythmias  Fetal infections 6 PREGNANCY RELATED  Multiple pregnancy  Gestational hypertension  Preeclampsia(PET)  Decreased fetal movement  Abnormal placentation  Placental abruption  Amniotic fluid disorders  PROM  GDM  Previous unexplained still birth  Post term pregnancy 7 WHEN TO START? Depends on factors like:-  Past history of adverse outcome  Severity of maternal and fetal conditions 8 CLINICAL ASSESSMENT  WEIGHT GAIN Recommended Ranges of Weight Gain During Singleton Gestations Stratified by Pre pregnancy Body Mass Index Category BMI Wt. in kg kg Low 19.8 12.5–18 Normal 19.8–25 11.5–16 High 26–29 7–11.5 Obese 29 7 (Williams 23rd ed.) Symphysis-fundal height (SFH) 10 Symphysis-fundal height  Measured from superior border of pubis symphysis to fundus  From 24th wks of gestation corresponds to period of gestation.  Difference of 3-4 cms acceptable  below 10th percentile or difference of >3-4cms suggests IUGR  Either large or small for GA.  positive predictive value of 60%  negative predictive value of 76.8% 11 Abdominal girth ( NOT COMMONLY USED)  Measured at lower border of umbilicus.  Increases by 2.5cm per week after 30wks.  95-100cms at term.  Static or falling values alarming sign. Fetal movement counting: kick counting or chart counting  the number of kicks in a certain time period.  By 20 weeks fetal movements.is felt... Fetal movement is one indicator of fetal health  most fetuses have circadian (biologically timed) activity rhythms and more active in the evening hours a fetus more active an hour after the mother eats due to the increase in blood glucose (sugar) in the mother's blood. A change in the normal number of fetal movements may indicate the fetus is under stress. Cont,  Quickening: start to feel those first kicks at about 16-25 weeks(average is about 20-22 weeks) -- or earlier if this isn't first pregnancy.  There are many ways to chart movements:  The simplest one is to record the amount of time it takes for her to feel 10 movements( should feel 10 movements in no more than 2 hours).  start counting movements at around 28 weeks.  Sleep cycle 20-40 min, rarely exceed 90 min 14 Fetal movement count  Fetus spends 10% of its time making gross fetal body movements  30 such movements made each hour.  Periods of active fetal body movement last about 40 minutes  Quiet periods last about 20 minutes.  Longest period without fetal movements about 75 minutes.  Mother appreciate 70% to 80% of gross fetal movements.  (GABBE 6TH ED.) 15 Factors affecting maternal perception of fetal movement  Fetal and placental factors :-  Placental location  The length and type of fetal movements  Amniotic fluid volume (AFV)  Maternal factors :-  Parity, obesity.  Psychological factors anxiety.  16 ULTRASOUND FOR FETAL PARAMETERS  HIGH RESOLUTION UTRASOUND  BASIC  TARGETED BASIC:(early pregnancy,1st term ultrasound screening test) Done at 10-14wks :-  No. of fetuses  Fetal ( heart, viability)  Gestational age- CRL  Any gross anomaly like anencephaly, limb reduction defects.  Nuchal translucency  Placental localization  Cervical length  maternal pelvic masses First trimester ultrasound 18 …. 2nd &3rd triemester  Serial measurements of BPD,AC,HC,FL.( growth us scan)  HC/AC ratio: exceeds 1 before 32wks. After 34wk falls below 1. In symmetric IUGR remains normal. Ratio can identify 85% IUGR fetuses.  FL/AC Ratio  AC remains single best parameter to detect IUGR AMNIOTIC FLUID VOLUME Single deepest pocket >2-8 cm normal Or Amniotic fluid index 5-25cm. (four quadrant technique.) 21 Targetted ultrasound : Detailed anomaly scan/ morphology scan  All patients– 18-22 w to check for congenital anomalies  Transverse section for fetal head  Shape and internal structures. BPD,HC Measured to detect hydrocephalus, anencephaly  Transverse and longitudinal views of abdomen to rule out anomalies of stomach, kidneys, bladder, ventral wall.  Transverse section of fetal thorax to four chambered view of heart. 22 Non stress test (CTG)  Freeman first described the NST in 1975.  Physiologic premise of the NST is that:- Non hypoxic fetus stimulus    accelerate its heart rate NST(CTG) 24 Ctg  Cardiotocography (CTG) is a continuous electronic record of the fetal’s heart rate  External obtained via a transducer placed on the Cardiotocography: mother’s abdomen.  It is sometimes referred to as ‘electronic  For continuous or intermittent fetal monitoring monitoring of the fetal heart rate and the activity of the uterine muscle.  Two transducers on the mother's abdomen(one above the fetal heart and the other at the fundus).  The tocodynamometer (“toco”) is placed over the uterine fundus. It provides information that can be used to monitor uterine contractions.  The second tranducer is placed over the area of the fetal back. This device transmits information about the FHR. 25 ….  Internal Cardiotocograph y:  Uses an electronic transducer connected directly to the fetal scalp through the cervical opening and is connected to the monitor.  Amniotic membranes must be ruptured  Cervix dilated 2 cm.  Presentation must be cephalic  Presenting part down against the cervix. 26 Method  Patient is placed in a lateral tilt position  FHR and uterine activity are monitored with an external transducer  FHR is monitored for 20 minutes.  For 40 minutes in some cases to compensates for sleep cycles then called EXTENDED NST.  In some cases when the fetus is not reactive, acoustic stimulation by artificial larynx a sound stimulus for 1 to 2 seconds. 27 Intrapartum CTG Interpretation  Baseline fetal heart rate (FHR)  Baseline FHR variability  Presence of accelerations  Decelerations  Uterine activity (contractions)  28 Fetal heart baseline  differentiate between fetal and maternal heartbeats  baseline fetal heart rate will usually be between 110 and 160 beats/minute.  Fetal Tachycardia :Baseline FHR greater than 160 beats per min  Fetal bradycardia : Sustained fetal heart rate less than 110 beats per minute 29 ….. 30 causes of fetal tachycardia :  Maternal fever  Chorioamnionitis  Fetal sepsis  Drugs (Atropine, Phenothiazines, Beta-sympathomimetics)  Tachyarrhythmias  Fetal heart failure  Severe fetal anemia, fetal hydrops  Maternal hyperthyroidism 31 Variability:  variability will usually be between 5 and 25 beats/minute  intermittent periods of reduced baseline variability are normal, especially during periods of sleeping. 32 Causes of decreased variability include:  Hypoxemia/acidosis  Fetal sleep cycles  Drugs (Analgesics, barbiturates, phenothiazines, anesthetics)  Prematurity  Arrhythmias  Pre-existing neurological abnormality  Congenital anomalies 33 34 Accelerations:  Increase in FHR greater than or equal to 15 bpm, for greater than or equal to 15 seconds from the onset to return to baseline.  The presence of accelerations, even with reduced baseline variability, is generally a sign that the baby is healthy.  The absence of accelerations on an otherwise normal cardiotocograph trace does not indicate fetal acidosis.  If digital fetal scalp stimulation (during vaginal examination) leads to an acceleration in fetal heart rate, regard this as a sign that the baby is healthy 35 Decelerations:  Decreases in fetal heart rate from the base line by at least 15b/m, lasting for at least 15 seconds 36 37 Types of deceleration  Early decelerations:  Begins at the start of uterine contraction and end with conclusion of contraction.  In most cases the onset, nadir(lowest point), and recovery of the deceleration are with the beginning, peak, and ending of the contraction, respectively (mirror like )  Its related to Head compression.  Early decelerations are a benign finding caused by a vasovagal response as a result of fetal head compression by the contraction.  No intervention necessary. Just continue to watch for any changes 38 39 Variable decelerations:  Variable decelerations are variable in duration, intensity, and timing.  Variable decelerations Abrupt(sudden) decrease in FHR of > 15 beats per minute measured from the most recently determined baseline rate.  The onset of deceleration to nadir is less than 30 seconds. The deceleration lasts > 15 seconds and less than 2 minutes.  Related to cord compression. 40 41 Late Decelerations:  Gradual decrease in FHR with onset of deceleration to nadir >30 seconds.  Onset of the decleration occurs after the beginning of the contraction, and the nadir of the deceleration occurs after the peak of the contraction.  Related to decreased uteroplacental perfusion 42 Late deceleration 43 ….  It is important to remember the following learning points regarding EFM:  It is used to identify intrapartum hypoxia – a significant cause of fetal death and disability; fetal hypoxia can lead on to fetal asphyxia and death.  It should not be used unless indicated as it increases the rates of caesarean section and instrumental delivery in low-risk women.  It has become an integral component of labour management in high- risk women. 44 …..  Intermittent auscultation of the fetal heart rate to women at low risk of complications in established first stage of labour:  Intermittent auscultation immediately after a contraction for at least 1 minute, at least every 15 minutes in the first stage of labour and and at least every 5 minutes in the second stage and record it as a single rate.  Palpate the maternal pulse hourly, or more often if there are any concerns, to differentiate between the maternal and fetal heartbeats. 45 ….  High-Risk pregnancies need continuous FHM :  Maternal medical illness ,Gestational diabetes, Hypertension ,Asthma.  Obstetric complications : Multiple gestation ,Post-date gestation ,Previous cesarean section ,Intrauterine growth restriction ,Oligohydramnios ,Premature rupture of the membranes, Congenital malformations ,Third- trimester bleeding.  Oxytocin induction/augmentation of labor, Preeclampsia ,Meconium stained liquor. 46 ….  Continuous cardiotocography if any of the following risk factors :  Maternal pulse over 120 beats/minute on 2 occasions 30 minutes apart  Temperature of 38°C or above on a single reading, or 37.5°C or above on 2 consecutive occasions 1 hour apart  Suspected chorioamnionitis or sepsis  The presence of significant meconium  Fresh vaginal bleeding that develops in labour  Severe hypertension: a single reading of either systolic blood pressure of 160 mmHg or more or diastolic blood pressure of 110 mmHg or more, measured between contractions  Hypertension: either systolic blood pressure of 140 mmHg or more or diastolic blood pressure of 90 mmHg or more on 2 consecutive readings taken 30 minutes apart, measured between contractions  A reading of 2+ of protein on urinalysis and a single reading of either raised systolic blood pressure (140 mmHg or more) or raised diastolic blood pressure (90 mmHg or more)  Confirmed delay in the first or second stage of labour  Contractions that last longer than 60 seconds (hypertonus), or more than 5 contractions in 10 minutes (tachysystole)  Oxytocin use. 47 48 Concerning characteristics of variable decelerations: -Lasting more than 60 seconds  Reduced baseline variability within the deceleration  Failure to return to baseline  Biphasic (W) shape 49 Categorise Cardiotocography traces as follows: -normal: all features are reassuring  suspicious: 1 non-reassuring feature  pathological: 1 abnormal feature or 2 non-reassuring features 50 51 52 CTG interpretation and further management  If CTG is normal: continue CTG or if it was started because of concerns arising from intermittent auscultation, remove CTG after 20 minutes if there are no non-reassuring/abnormal features and no ongoing risk factors.  If suspicious: commence conservative measures – left lateral position, oral/intravenous fluids, stop oxytocin, consider tocolysis.  If the CTG is abnormal: Offer to take fetal blood sample (FBS; for lactate or pH) after implementing conservative measures, or expedite birth if an FBS cannot be obtained and no accelerations are seen as a result of scalp stimulation. 53 54 Fetal blood sampling interpretation  Normal(PH:>=7.25): and there are no accelerations in response to fetal scalp stimulation, consider taking a second fetal blood sample no more than 1 hour later if this is still indicated by the cardiotocograph trace.  Borderline (PH 7.21-7.24): and there are no accelerations in response to fetal scalp stimulation, consider taking a second fetal blood sample no more than 30 minutes later if this is still indicated by the cardiotocograph trace.  Abnormal (PH