Significance of Pulmonary Vein Pulsatility Index (PVPI) in detecting Fetal growth restriction(FGR) and it’s correlation to umbilical cord pH- a case control study

Fetal Growth Restriction is a failure of the fetus to reach its expected biological growth, based on its genetically predetermined potential. Whenever effective fetal weight is less than, 10th percentile or 2 standard deviation of population specific growth curve, it is considered small for gestational age(SGA). The FGR is a pathological state, based on additional criteria of EBW <3dr percentile, poor somatic growth and compensated umbilical/cerebral blood flow and is associated with poor somatic growth with concomitant changes in placental and cerebral blood flow and/or biochemical markers along with EBW<3rd percentile a common condition affecting about 10-15% of general maternity population.

It is associated with increased risk of Intrauterine Fetal Death (IUFD), intracranial hemorrhage, respiratory distress syndrome, neonatal lung disease, necrotizing enterocolitis, chronic cardiovascular disorders and renal disorders.

FGR fetuses are at increased risk of perinatal morbidity and mortality.

Fetal Doppler studies is an expanding field, and functional studies are now an essential part of the routine examination. Fetal venous Doppler studies represent valuable diagnostic techniques that can influence the management of FGR fetus as it helps in identification of the fetus at risk for perinatal complications and help in prediction of neonatal complications.

Alterations of venous flow volume forms precede fetal heart rate deaccelerations offering warning sign to act before a fetal life-threatening situation occurs. Doppler assessment of the venous system is important in the surveillance of compromised growth restricted fetus, as it can improve perinatal mortality and morbidity by optimizing time of delivery?

The Doppler indices measured from the ductus venosus, umbilical arteries ,Cerebro-placental and umbilico- cerebral Doppler ratio have been shown to correlate with the wellbeing of fetal growth restricted fetuses, which includes umbilical artery pH.

Umbilical artery pH (UApH) is essential for assessing adverse pregnancy outcomes since it predicts the risk that neurodevelopmental problems will manifest in childhood. However evidence during past two decades has shown that Small for Gestational Age (SGA), as defined by a normal UA pulsatility index, contains a large proportion of foetuses with worse perinatal outcomes than normally grown foetuses and thus UA Doppler cannot be a standalone criterion to differentiate FGR from SGA.

Ductus venous is the strongest single Doppler parameter to predict the short term risk of fetal death in early onset FGR however DV waveforms become abnormal only in advanced stages of fetal compromise. This study will therefore help in assessing fi PVPI can be used as a predictor of adverse perinatal outcome before Ductus Venosus (DV) changes appear.

This study therefore aims to observe the importance of Pulmonary Vein Pulsatility Index (PVPI) in predicting adverse perinatal and postnatal outcomes in FGR in clinical practice and

to investigate the relationship between Pulmonary Vein Pulsatility Index (PVPI) and umbilical cord pH in FGR neonates especially in India as there is insufficient literature on the subject and a gap in the knowledge on the subject.

Since umbilical artery blood is difficult to access in neonates, it is rather a more practical approach to take umbilical cord blood pH as a marker and not specifically umbilical artery pH as ti may lead to inefficient results.

STUDY PROTOCOL- All the willing pregnant women who are more than 28 weeks coming to KAHER’S Dr. Prabhakar Kore Hospital delivering in labour rooms or undergoing Caesarean sections will be included in the study.

After obtaining approval from the ethical committee, permission will be taken for a waiver of consent.

The patients who satisfy the inclusion criteria and do not fall under the exclusion criteria will be recruited in the study.