Despite the fact that most perinatal and maternal complications are on the decline in diabetic pregnancies, the rate of congenital malformations has not changed over the past twenty years.1 In fact, congenital malformations have replaced asphyxia and respiratory distress syndrome as the leading cause of mortality in offspring born to mothers with insulin-dependent diabetes mellitus.2 The frequency of major congenital malformations has been estimated at 6 to 10% representing a three to five fold increase over the rate in the general population.3,4 Congenital malformations in the offspring of women with diabetes represent a significant social and financial burden to society.