Biophysical profile score (BPS) as a predictor of poor outcome in preterm fetal growth restriction (FGR): A multicenter study

Abstract

Arteriovenous Doppler is key to identifying severe FGR, but recent trials suggest delivery may be provoked earlier than ideal, when Doppler is used alone. Our study assessed utility of Biophysical Profile Scoring in predicting poor neonatal outcome in FGR fetuses delivered <32 weeks gestational age (GA). Multicenter prospective study. FGR fetuses (abdominal circumference <5%, elevated umbilical artery Doppler) had serial BPS (Manning). In those delivered <32 weeks, BPS at delivery was related to acidosis, Apgar score, neonatal outcome including respiratory distress (RDS), bronchopulmonary dysplasia (BPD), retinopathy (ROP), intraventricular hemorrhage (IVH), leukomalacia (PVL) enterocolitis (NEC)) and composite morbidity. Chi-square assessment of distribution and Mantel-Haenzel test for dichotomous outcomes, were used. Among 224 FGR neonates mean birth GA was 28.6 (±1.8) weeks, birthweight 851 (±254) g. Normal BPS (>6) significantly reduced the likelihood of pH <7.2 (Odds ratio (OR) 0.13, 95% confidence interval (CI) 0.07-0.025), 5 minute Apgar <7 (OR 0.14, CI 0.07-0.29), IVH (OR 0.32, CI 0.7-0.62), NEC (OR 0.30, CI 0.13-0.72) and perinatal mortality (OR 0.23, CI 0.11-0.49, all p<0.001). Abnormal BPS (<6) significantly increased chances of pH < 7.2 (OR 8.93, CI 4.87 – 16.37), 5 minute Apgar <7 (OR 7.58, CI 4.10- 14.01), IVH (OR 4.33, CI 2.37 – 7.88), PVL (OR 6.16, CI 1.32 – 28.78) and perinatal mortality (OR 5.42, CI 2.82- 10.40, all p<0.05). Equivocal BPS (6/10) did not discriminate outcome classes. Biophysical profile scoring is an accurate predictor of adverse outcome in early onset FGR. Risks of adverse outcome are reliably stratified by individual scores, allowing confident patient counseling. Safe prolongation of pregnancy in presence of a normal BPS may optimize gestational time, and improve perinatal outcome. Conversely, high likelihood of poor outcome validates delivery for abnormal scores. Demonstration of these BPS principles in early severe IUGR provides strong impetus for a randomized management trial.