Prevention of congenital malformations in infants of insulin-dependent diabetic mothers.

From April 1977 to April 1981, 420 deliveries of infants of insulin-dependent diabetic women were performed in our department. Of the infants delivered, 23 had congenital malformations (5.5%). The malformation rate was 1.4% for infants of 420 nondiabetic women. Strict metabolic control was begun after 8 wk gestation in 292 of the diabetic women who delivered 22 infants with congenital malformations (7.5%). Intensive treatment was begun before conception in 128 diabetic women planning pregnancy. There was only one malformation in infants of this group (0.8%), a significant reduction from the anomaly rate in the late registrants (X2 = 7.84; P less than 0.01). These observations indicate that reasonable metabolic control started before conception and continued during the first weeks of pregnancy can prevent malformations in infants of diabetic mothers.