CONGENITAL-MALFORMATIONS IN INFANTS OF DIABETIC MOTHERS

Abstract

In a series of 701 infants born to diabetic women between 1950-1974, 57 (8.1%) had congenital malformations which is a rate 3-4 times higher than in the normal population of Birmingham [England]. In 26 cases (3.8%) the malformations were fatal and accounted for 26% of the perinatal mortality in the series. CNS, cardiovascular and skeletal abnormalities were equally common and there was a high incidence of anencephalus, spina bifida, transposition of the great vessels and sacral dysgenesis. Among pregnant women managed on dietary carbohydrate restriction alone because of a slight abnormality of glucose-tolerance test (White class A) the risk of congenital malformations was not increased. However, more severe diabetes (White classes B, C, D, F) was associated with a high incidence of malformations. Women whose diabetes had set in before 20 yr of age had a higher incidence of infants with malformations that were fatal than women who developed diabetes at an older age. Using the White classification, the risk of congenital malformations was similar for classes B, C and D + F, affecting 1 in 10 infants, while one in 13 had major malformations. Fatal malformations accounted for the death of 1 in every 25 infants and the risk was twice as high in classes C and D + F as in class B. Although the risk of congenital malformations in the offspring of overt diabetics is high (1 in 10), it is difficult to justify any dogmatic policies and an individual approach to the problems of each patient should be adopted.