antenatal assessment of Fetal wellbeing

antenatal Fetal wellbeing assessment

1. ANTENATAL ASSESSMENT OF FETAL WELL BEING PRESENTER – Dr K Harish Reddy

2. AIMS Assess fetal health and well being that are at risk due to - preexisting maternal conditions - pregnancy related complications timely delivery / prevent fetal harm decrease perinatal morbidity.

3. COMPONENTS CLINICAL MONITORING BIOPHYSICAL MONITORING BIOCHEMICAL MONITORING

4. CLINICAL MONITORING MATERNAL WEIGHT GAIN - 2 nd trimester – avg weight gain – 1 kg/ fortnight - excess – 1 st sign of preeclampsia - less / stationary – IUGR ASSESSMENT OF SYMPHYSIS-FUNDAL HEIGHT - after 24 weeks – corresponds to GA BLOOD PRESSURE OEDEMA OF FEET

5. BIOPHYSICAL MONITORING ANTEPARTUM TESTS FETAL MOVEMENT MONITORING NON STRESS TEST CONTRACTION STRESS TEST BIOPHYSICAL PROFILE MODIFIED BPP DOPPLER USG INTRAPARTUM TESTS CONTINUOUS ELECTRONIC FETAL MONITORING FETAL SCALP BLOOD GAS

6. BASIS FOR TESTS Hypoxia Metabolic acidosis CNS depression Changes in fetal biophysical activity

7. FETAL MOVEMENT MONITORING Simplest method Mothers perceive 88% of movements detected by doppler imaging Performed daily from 28 wks Cardif count of 10 formula Daily fetal movement count

8. RCT in denmark /2012 FM counting-73%reduction in available stillbirths Cochrane review though more no.of babies at risk of death were identified/no reduction in perinatal mortality

9. NON STRESS TEST Based on the hypothesis that the HR of a fetus will temporarily accelerate in response to fetal movements. Testing - started after 30 wks and frequency should be twice weekly Simultaneous recording of 1.Fetal heart rate 2.Uterine activity

10. Simple to perform Relatively quick Noninvasive Valuable to identify fetal well being than illness.

11. INTERPRETATION 1. REACTIVE HR -110-160 bpm normal beat to beat variability(5 bpm) 2 accelerations of atleast 15 bpm above baseline, each lasting 15 seconds within 20 minutes period. 2.NONREACTIVE- TEST repeated later on same day/another testing 3.INADEQUATE VIBROACOUSTIC STIMULATION

12. EVIDENCE Studies show that risk of fetal demise within the week following a reactive nst is approx.is 3 in 1000 But when nst is nonreactive,perinatal death is about 40 per1000

13. NON REACTIVE NST

14. CONTRACTION STRESS TEST Records FHR in response to uterine contractions Uterine contraction – IV oxytocin / nipple stimulation Based on principle - uterine contractions can compromise unhealthy fetus . Pressure generated during contractions-reduce or eliminate perfusion of intervillous space Healthy fetoplacental unit has sufficient reserve to tolerate this short reduction in O2 supply Under pathological conditions, reserve may be so compromised that reduction in O2 results in fetal hypoxia.

15. Satisfactory test if uterine contraction has spontaneously occurred within 30 min lasted 40-60 seconds each occurred at a freq of 3 within 10 minute interval Unsatisfactory – change mode of stimulation. POSITIVE - late decelerations noted after 50% or more of contractions. NEGATIVE - Good EQUIVOCAL - late decelerations noted befor 50% of contractions.

16. EVIDENCE Negative CST is more reassuring than reactive NST/with a chance of fetal demise within a week of a negative CST approx.0.4 per 1000 Positive CST following nonreactive NST - risk of stillbirth - 88 per 1000 and - risk of neonatal mortality 88 per 1000. Statistically, about 1/3 rd of patients with positive CST will require caesarian section for persistent late decelerations in labour.

17. BIOPHYSICAL PROFILE NST + US examination Not useful in active labour

18. BIOPHYSICAL PROFILE PARAMETERS MINIMAL NORMAL CRITERIA SCORE NST REACTIVE 2 FETAL BREATHING MOVTS >1 EPISODE LASTING >30 SEC 2 GROSS BODY MOVTS >3 DISCRETE BODY/LIMB MOVTS 2 FETAL MUSCLE TONE >1 EPISODE OF EXTENSION (LIMB OR TRUNK)WITH RETURN OF FLEXION 2 AMNIOTIC FLUID >1 POCKET MEASURING 2 CM IN 2 PERPENDICULAR PLANES (2X2 CM POCKET) 2

19. INTERPRETATION

20. All components – not equally predictive High risk – weekly screening Steroids – can change results. Likelihood of in utero fetal demise within 1 week of a reassuring test is approx. 0.6-0.7 per 1000

21. US DOPPLER VELOCIMETRY Direction and characteristics of blood flow of Umbilical artery. Umbilical artery ? measure resistance to blood flow from fetus to placenta. Factors – GA , placental location, complications (abruptio, preeclampsia) , maternal disease.

22. Measure of placental function and fetal status. S/D ratio Resistance index – S-D / S Pulsatility index – S-D / A

23. Abnormal (absent / reversed EDBF) + FGR – omnious sign. Unclear if fetus is normal. So generally not done in low risk pregnancies Indications – FGR - Cord malformations - unexplained oligohydramnios - preeclampsia - cardiac anomalies

24. Not useful for high risk cases – GDM, Postterm pregnancies – high false positive rates Umbilical artery Doppler velocimetry in conjunction with other tests of fetal being can reduce perinatal mortality in IUGR by almost 40% Doppler measurements of middle cerebral artery can also be used in assessment of fetus at risk of either IUGR/ anemia

25. OTHER ASSESSMENT BY AN USG Viability of fetus Pregnancy dating Detection of multiple pregnancies Detection of congenital anomalies Placental localisation Monitoring of high risk pregnancies Adjunct to any procedure like amniocentesis/ cordocentesis /ECV

26. USG estimn of gestational age 1 ST trimester Fetal crown rump length-accurate predictor of GA CRL estimation of GA -within 7 days of true GA 2 ND and 3 RD trimester BPD and FL Accuracy of GA estimated by BPD decreases by increasing GA at 14-20 wks -variation upto 11 days at 20-28 wks -variation upto 14 days at 29-40 wks -variation upto 21 days

27. BIOCHEMICAL MSAFP Produced by yolksac and liver Done between 15-20 wks Elevated Wrong GA NTD Multiple preg IUFD Anterior abdominal wall defects Renal anomalies LOW LEVELS-TRISOMY/GTD

28. SCREENING FOR DOWN SYNDROME 1 ST trimester- PAPP-A B HCG}65% NUCHAL FOLD >4MM AT 8-12 WKS}57-73%COMBINED 85% 2 nd trimester HI-INIBIN/HCG LOW AFP/E3 TRIPLE TEST-69% QUADRUPLE-76% ALL COMBINED-94%

29. CVS/AMNIOCENTESIS/CORDOCENTESIS CVS AMNIOCENTESIS CORDOCENTESIS TIME 10-12 WEEKS 14-16WKS 18-20 WKS MATERIAL TROPHOBLAST CELLS FETAL FIBROBLATS/FLUID FOR BIOCHEM STUDY FETAL WBC FETAL LOSS 0.5-1% 0.5% 1-2% ACCURACY MY NEED FURTHER HIGHLY ACCURATE HIGHLY ACCURATE TERMINATION OF PREG 1 ST TRIM-SAFE 2 ND -RISKY 2 ND RISKY MATERNAL EFFECTS FOLLOWING TERMINATION LITTLE MORE TRAUMATIC SAME

30. ASSESSMENTOF FETAL LUNG MATURITY 1.Amniotic fluid L/S ratio 31-32 wks-1 35 wks 2 >2 indicates pulm maturity 2.Shake test/bubble test ( clement”s ) 3.Foam stability index->47 excludes RDS 4.Phosphatidyl glycerol in amniotic fluid 5.Saturated phophatidyl choline 6.Flourescence polarisation 7.AF optical density 8.Lamellar bodynile blu sulfate test

31. THANK YOU