Comparison of Fetal Growth Standards for Predicting Small‐for‐Gestational‐Age Infants and Adverse Pregnancy Outcomes

Objectives To compare the performance of 3 fetal growth standards—Hadlock, the Asian standards of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD.a), and Hong Kong standards—in predicting small‐for‐gestational‐age (SGA) infants and associated adverse pregnancy outcomes (APO) in a Southern Chinese population. Methods Retrospective multicenter cohort study of 2763 singleton pregnancies (28–40 weeks). Estimated fetal weight (EFW) was calculated using the Hadlock formula, and SGA was defined as EFW <10th percentile for gestational age and sex. Receiver operating characteristic curves were generated to assess the predictive capability of each growth standard. Multivariable logistic regression analyses were conducted to identify predictors of APO. Results NICHD.a standards showed the highest overall predictive performance for SGA infants (AUC = 0.801), similar to Hadlock standards (AUC = 0.801) and higher Hong Kong standards (AUC = 0.788). For APO, NICHD.a had higher sensitivity; Hong Kong had higher specificity. Independent APO predictors included maternal age, nulliparity, IVF‐ET, and umbilical artery abnormality. Conclusions NICHD.a fetal growth standards were more effective than both Hadlock and Hong Kong standards in predicting SGA infants and associated APO in this Southern Chinese cohort.