Prediction of small-for-gestational age neonates at 35-37 weeks’ gestation: contribution of maternal factors and growth velocity between 32 and 36 weeks

Abstract

OBJECTIVE: To assess the additive value of fetal growth velocity between 32 and 36 weeks' gestation to the performance of ultrasonographic estimated fetal weight (EFW) at 35 + 0 to 36 + 6 weeks' gestation for prediction of delivery of a small-for-gestational-age (SGA) neonate and adverse perinatal outcome. METHODS: This was a prospective study of 14 497 singleton pregnancies undergoing routine ultrasound examination at 30 + 0 to 34 + 6 and at 35 + 0 to 36 + 6 weeks' gestation. Multivariable logistic regression analysis was used to determine whether addition of growth velocity, defined as the difference in EFW Z-score or abdominal circumference (AC) Z-score between the early and late third-trimester scans divided by the time interval between the scans, improved the performance of EFW Z-score at 35 + 0 to 36 + 6 weeks in the prediction of, first, delivery of a SGA neonate with birth weight < 10 RESULTS: Multivariable logistic regression analysis demonstrated that significant contributors to the prediction of a SGA neonate were EFW Z-score at 35 + 0 to 36 + 6 weeks' gestation, fetal growth velocity, by either AC Z-score or EFW Z-score, and maternal risk factors. The area under the receiver-operating characteristics curve (AUC) and detection rate (DR), at a 10% screen-positive rate, for prediction of a SGA neonate < 10 CONCLUSION: The predictive performance of EFW at 35 + 0 to 36 + 6 weeks' gestation for delivery of a SGA neonate and adverse perinatal outcome is not improved by addition of estimated growth velocity between 32 and 36 weeks' gestation. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.