Mechanisms of congenital malformations in diabetic pregnancy.

The reasons for the increased rate of congenital malformations in diabetic pregnancy are unclear. Several different teratological agents may be considered. In clinical investigations and animal experimentation hyperglycemia and hypoglycemia, hyperketonemia, altered trace metal metabolism, and a genetic predisposition have been suggested to be of significance in the teratogenic process of diabetic pregnancy. Studies of these possible etiological factors have so far failed to reveal a single agent or mechanism as the most important. The diabetic pregnancy, therefore, appears to be of multifactorial origin.