Minor congenital malformations in infants of insulin-dependent diabetic women: association with poor glycemic control.

A prospective study of 171 insulin-dependent diabetic pregnant women was undertaken to establish the relationship of glycemic control with minor congenital malformations. Each live-born infant was assessed systematically by two independent examiners using a standardized checklist. There were 32 infants with minor congenital malformations (18.7%). There were significant differences in mean glycohemoglobin A1 between the group with minor congenital malformations and the group without congenital malformations at 12, 16, and 20 weeks, but not at 8 or 24 weeks. Logistic regression analysis showed that maternal age, race, gravidity, White class, duration of diabetes, maternal vasculopathy, and cigarette smoking were not significant variables correlated with minor congenital malformations. Because glycohemoglobin levels from 12-20 weeks are believed to reflect glycemic control from approximately 6-20 weeks, we conclude that poor glycemic control during late embryogenesis and early fetal development is associated with an increased risk of minor congenital malformations. We speculate that improvement of glycemic control during this period should decrease the risk of minor congenital malformations.