Abstract
OBJECTIVE: To see whether a prepregnancy clinic for diabetic women can achieve tight glycaemic control in early pregnancy and so reduce the high incidence of major congenital malformation that occurs in the infants of these women. DESIGN: An analysis of diabetic control in early pregnancy including a record of severe hypoglycaemic episodes in relation to the occurrence of major congenital malformation among the infants. SETTING: A diabetic clinic and a combined diabetic and antenatal clinic of a teaching hospital. PATIENTS: 143 Insulin dependent women attending a prepregnancy clinic and 96 insulin dependent women managed over the same period who had not received specific prepregnancy care. MAIN OUTCOME MEASURE: The incidence of major congenital malformation. RESULTS: Compared with the women who were not given specific prepregnancy care the group who attended the prepregnancy clinic had a lower haemoglobin AI concentration in the first trimester (8.4% v 10.5%), a higher incidence of hypoglycaemia in early pregnancy (38/143 women v 8/96), and fewer infants with congenital abnormalities (2/143 v 10/96; relative risk among women not given specific prepregnancy care 7.4 (95% confidence interval 1.7 to 33.2]. CONCLUSION: Tight control of the maternal blood glucose concentration in the early weeks of pregnancy can be achieved by the prepregnancy clinic approach and is associated with a highly significant reduction in the risk of serious congenital abnormalities in the offspring. Hypoglycaemic episodes do not seem to lead to fetal malformation even when they occur during the period of organogenesis.