Multi vessel doppler velocimetry and biophysical PROFILE complement each other for antenatal survelliance in high risk pregnancies
High risk pregnancies are complex as they place the mother and fetus at risk for complications. They are associated with increased perinatal morbidity and mortality. They include maternal conditions such as hypertensive disorders, diabetes, cardiac, renal, autoimmune disorders, thrombophilias and obstetrical conditions such as fetal growth restriction, multiple pregnancy, oligohydramnios, antepartum hemorrhage and prolonged pregnancy. The aim of antenatal monitoring is to identify the fetus at risk of intrauterine injury or deathand give time to initiate measures so that the adverse outcomes can be prevented. Numerous fetal surveillance tests have been developed for this purpose but there exists limited evidence to guide their appropriate application. Antenatal fetal monitoring techniques include – fetal movement count, cardiotocographic assessment including non stress test and contraction stress test, Biophysical profile and amniotic fluid measurement and Doppler velocimetry.
Comparative studies are lacking for high risk pregnancies. Biophysical profile is a time consuming and expensive modality. Although observational studies have suggested that BPP confers benefit in high risk pregnancies, the financial and manpower costs involved in performing a BPP are much higher. So, this study was planned to study whether BPP in high risk pregnancies offers any benefit over multi vessel Doppler velocimetry in predicting adverse perinatal outcome. If deteriorations in both BPP and Doppler velocimetry are closely related, then Doppler may replace BPP for fetal surveillance. However, if the results are discordant, then an integrated approach would benefit. This study was therefore planned to compare Doppler velocimetry with Biophysical profile for fetal surveillance in high risk pregnancies.
It was a prospective observational study done over 2 years in a tertiary care center in Delhi. 186 women with high risk pregnancies who met the inclusion criteria were enrolled for the study. They were divided into 2 groups – group 1, those with growth restricted fetus and group 2- those without growth restricted fetus. Fetal monitoring was done with weekly Biophysical profile and Doppler velocimetry of the fetal umbilical artery and middle cerebral artery. The S/D, PI and RI were measured for the umbilical artery and middle cerebral artery. These were then correlated with neonatal outcomes and complications.
A total of 186 women were enrolled for the study. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for BPP in growth restricted fetus was 93.3%, 88.2%, 87.5%, 93.7% as compared to 81.8%, 70.5%, 78.2%, 75% for doppler. 12 were lost to follow up. The NcNemar Bowker Chi square test showed that the results of doppler and BPP for predicting adverse perinatal outcome in fetus with growth restriction was concordant. On comparing the test results of doppler with BPP in group II using McNemar Bowker Chi square test, the results were not found to be concordant (p=0.001).
Antepartum fetal testing has been a matter of great concern among the obstetricians. Over the years, various methods have been devised, used, studied and critically analysed in order to get a better predictor for perinatal outcome. The modalities in modern practice include NST, amniotic fluid estimation, BPP and Doppler velocimetry of fetal blood vessels. The present study was done to compare the two methods of fetal monitoring i.e. Doppler and BPP so as to find out which of the two is an earlier and better predictor of fetal compromise in high risk pregnancies. Whether Doppler which is a less time consuming method can replace BPP as a method of fetal monitoring in high risk pregnancies? There were two groups of babies - those with growth restriction (group I) and without growth restriction (group II). Though the mean gestational age at delivery for both the groups was similar, there was significant difference in the birth weight, apgar score and nursery admissions. This was due to the low birth weight of the growth restricted fetus. The adverse perinatal outcomes in group I exceeded those of group II showing that the low birth weight and the complications associated with growth restriction makes this group different from other high risk fetus. In the present study, authors observed that with worsening doppler and BPP scores, the number of days of hospital stay and admission to nursery increases. Both doppler and BPP show a good sensitivity and positive predictive value, so they are valuable in predicting adverse perinatal outcome in growth restricted fetus. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for BPP in growth restricted fetus was 93.3%, 88.2%, 87.5%, 93.7% as compared to 81.8%, 70.5%, 78.2%, 75% for doppler. Though BPP appears to be a better predictor of adverse outcome, but when compared by McNemar Chi square test, the results of the two are similar. That implies that one test can replace the other for antenatal survelliance in growth restricted fetuses. Also doppler changes have been shown to preceed changes in BPP scoring. Therefore, we can propose to replace BPP with doppler for antenatal survelliance of growth restricted fetus as it is less time consuming compared to BPP and is an earlier predictor of adverse perinatal outcome.
In group II, that is those with high risk but non growth restricted fetus, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for doppler was 98.2%, 0, 78.5%, 0 and for BPP 93.3%, 12.5%, 80%, 33.3% . Though doppler is highly sensitive with a good PPV but specificity and NPV fall to 0. On comparing the two tests using McNemar chi square test, the results were non concordant, that is dissimilar. Therefore, in this group of fetus, the cardiovascular and behavioural changes as represented by doppler and BPP appear to be independent of each other. The two test are complementary to each other.
Both Doppler and BPP results can be used to stratify fetus for prognostication. In growth restricted fetus, doppler may replace BPP for antenatal survelliance but in other high risk fetus, they do not show a consistent relation with one another and can complementeach other for antenatal survelliance.
Source: Sharma et al. / Indian Journal of Obstetrics and Gynecology Research 2025;12(3):437–442
