Prediction of small‐for‐gestational‐age neonates at 19‐24 weeks’ gestation : role of uterine artery Doppler screening

Small-for-gestational-age (SGA) neonates are at increased risk for perinatal mortality and morbidity. However, the performance of uterine artery pulsatility index values (UtA-PI) at 19-24 gestational weeks to predict delivery of SGA neonates is controversial in the literature, and there is no such study in Chinese population. We aimed to investigate the performance of UtA-PI in the prediction of SGA neonates in Chinese population.A retrospective cohort study was conducted between January 2010 and June 2018. Doppler ultrasonography was performed at 19-24 gestational weeks. SGA was defined as birthweight below the 10th centiles according to the INTERGROWTH-21st fetal growth standards. The performance of UtA-PI to predict SGA neonates was assessed using receiver operating characteristic curve (ROC) analysis.We included 6964 singleton pregnancies, and there were 748 (9.9%) women who delivered SGA neonates including 115 (9%) women with preterm delivery. UtA-PI was associated with the risk of SGA in both SGA delivered at <37 gestational week (preterm SGA) and SGA ≥37th gestational week (term SGA). The areas under the ROC (AUCs) for UtA-PI were 75.8% [95% confidence interval (CI) 69.3%-82.3%] and 64.4% (95% CI 61.5%-67.3%) for preterm SGA and term SGA. The performance of combined screening by maternal demographic characteristics and estimated fetal weight in detection of preterm SGA and term SGA was improved by the addition of UtA-PI. However, the increase in AUC by adding UtA-PI to maternal demographic characteristics and estimated fetal weight was only modest (4.9% for preterm SGA and 2.4% for term SGA).This study is the first Chinese study which has evaluated the role of UtA-PI at 19-24 weeks' gestation in the prediction of SGA. Our findings suggest that UtA-PI can improve the screening performance of SGA on top of traditional risk factors, and the improvement was greater in predicting preterm SGA than term SGA. This article is protected by copyright. All rights reserved.