Large-for-gestational-age or macrosomia as a classifier for risk of adverse perinatal outcome: a retrospective cross-sectional study.

Objective: Small for gestational age (SGA) fetuses and neonates are of great interest, while those who are too big are much less studied. The aim was to analyze the classifiers described by ACOG "Fetal macrosomia" practice bulletin as predictors of adverse perinatal outcomes for overgrown fetuses and their mothers.

Materials: From a database of 53,586 singleton term births, appropriate-for-gestational-age (AGA), large for gestational age (LGA), and macrosomic deliveries were selected. AGA served as a control. The crude and adjusted odds ratios (aORs) were calculated for large-for-gestational-age >90th centile, and macrosomia >4000 g, >4250 g, and >4500 g. Patients with and without diabetes were analyzed separately

Results: Macrosomia >4000 g performed poorer than other classifiers. LGA performed comparably to other definitions of macrosomia. Diabetes carries a severe risk of complications for overgrown neonates, but those non-diabetic also have increased risk.

Conclusions: Definition of macrosomia as weight >4000 g should be reconsidered. LGA >90th centile should be used as a definition of fetal overgrowth along with other definitions of macrosomia.