Infants of diabetic mothers with abnormal fetal growth missed by standard growth charts.

Diabetic pregnancies may result in fetal macrosomia when glycaemia is poorly controlled, and when associated with diabetic vasculopathy, with small for gestational age (SGA) neonates. Both groups of infants have high neonatal morbidity. As fetal growth depends on maternal genetic influences, ethnic group or parity, relying exclusively on population-based growth charts may wrongly categorise the growth pattern of these infants. We compared neonatal morbidity and mortality of a cohort of 214 infants of diabetic mothers (IDM), identified either by population standards or by customised birth weight percentiles (adjusted for maternal height, booking weight, parity, ethnic origin, gestational age at delivery and sex). A total of 68 (31.8%) were diagnosed with macrosomia, 11 (16%) of whom were identified by the customised growth method alone, and 16 were diagnosed as SGA (7.5%), of whom the majority (13 or 81.2%) were identified by the customised growth method alone. None had increased mortality and morbidity.