Fetal macrosomia has been defined in several different ways, including birth weight of 4000-4500 g (8 lb 13 oz to 9 lb 15 oz) or greater than 90% for gestational age after correcting for neonatal sex and ethnicity. Based on these definitions, macrosomia affects 1-10% of all pregnancies. A diagnosis of fetal macrosomia can be made only by measuring birth weight after delivery; therefore, the condition is confirmed only retrospectively, ie, after delivery of the neonate.