Efficacy of Pulsatility Index of Fetal Vessels in Predicting Adverse Perinatal Outcomes in Fetuses with Growth Restriction - Differences in Early- and Late-Onset Fetal Growth Restriction.

Abstract

Background:Doppler ultrasound of fetal vessels plays an important role in diagnosing fetal growth restriction (FGR). It also aids in early detection of fetal compromise and clinical decision making. Aim: To determine the efficacy of the pulsatility index (PI) of the fetal umbilical artery (UA) and middle cerebral artery (MCA) in the third trimester of pregnancy for predicting adverse perinatal outcomes in the growth restricted fetuses. To study the differences in Doppler profiles in early- and late FGR (EFGR and LFGR, respectively) and their association with adverse outcomes. Materials and methods:The study was approved by the Institute's Ethical Committee. Informed consent was taken from study participants. Eighty singleton pregnancies in the third trimester, which had been diagnosed with FGR, were studied. The UA and MCA Doppler PI and cerebroplacental ratio (CPR) (ratios of PI of MCA/UA) as well as perinatal outcomes were recorded. Adverse perinatal outcomes included perinatal death, hypoxia, seizures, respiratory distress, prolonged Neonatal Intensive Care Unit (NICU) stay, and low Apgar scores at one minute and five minutes. Statistical association of PI with adverse outcomes and differences in Doppler profiles of EFGR and LFGR were studied. Results:Abnormal pulsatility in fetal vessels was associated with adverse perinatal outcomes. The UA PI was the most sensitive (66%) and CPR the most specific parameter (80%) for predicting adverse perinatal outcomes. Absent or reversal of diastolic flow in UA was associated with adverse perinatal outcomes in 75% and 40% of cases, respectively. The UA PI was the most sensitive parameter in both EFGR (70%) and LFGR (66%) and specific Doppler parameter in EFGR (75%). However, CPR and MCA PI were the most specific (89%) and diagnostically accurate in LFGR (79%). Conclusion:The UA PI is the most sensitive Doppler parameter for predicting adverse perinatal outcomes. Cerebroplacental ratio has a high specificity and accuracy and is an important parameter in LFGR cases.