Integration of fetal doppler with routine antenatal third-trimester ultrasound significantly reclassifies the magnitude of fetal growth restriction in northern India.

Abstract

Purpose: To determine the magnitude of fetal growth restriction (FGR) using fetal Doppler integrated with antenatal ultrasound in third-trimester screened pregnant women at Agra in northern India.

Methods: Screened participants underwent routine third-trimester ultrasound assessments integrating fetal Doppler studies. Any one or more of mean uterine artery (UtA) or umbilical artery (UA) pulsatility index > 95th centile, middle cerebral artery (MCA) or cerebroplacental ratio (CPR) PI < 5th centile, absent or reversed end-diastolic velocity, or ductus venosus PI > 95th centile was considered abnormal Doppler studies. Fetuses with estimated fetal weight (EFW) < 3rd percentile or EFW 3rd to 10th percentile with abnormal Doppler were categorised as FGR. Fetuses with EFW 3rd to 10th percentile and normal Doppler were classified as small for gestational age (SGA) and EFW 10th to 50th percentile and abnormal Doppler were classified as appropriate for gestational age (AGA) fetuses with adapted growth restriction.

Results: Among 1065 screened participants, 142 fetuses (13.33%) had an EFW < 10th centile and 139 (13.05%) fetuses had both EFW and fetal AC < 10th centile. Stage 1 FGR was identified in 58 (5.45%) fetuses, 75 fetuses (7.04%) were classified as SGA and 77 (7.23%) were adapted growth-restricted AGA fetuses. Reclassifying FGR after integrating Doppler assessments reduced magnitude by 52.13, 51.11, and 76.82% from the estimates of FGR derived based on EFW < 10th centile alone, both EFW and fetal AC < 10th centile and either EFW or fetal AC < 10th centile respectively.

Conclusion: Integrating fetal Doppler studies with routine third-trimester ultrasound assessment significantly reclassifies FGR with a huge reduction in the proportion of fetuses that need more intense surveillance in the third trimester.