The effect of glycemia on early embryonic development in diabetic pregnancies

Objectives This study assessed the correlation between early embryonic grow th and maternal glycemia, as well as between early embryonic growth restric tion and incidence of spontaneous abortions and of congenital malformations . Methods The prospective study included 102 pregnant women with insulin-depe ndent diabetes mellitus and 192 matched healthy controls. All women had reg ular periods. The level of serum chorionic gonadotropin was determined at l east twice: at 6-8 weeks of pregnancy and before 12 weeks of pregnancy. A s ingle measurement of maternal glycosylated hemoglobin, two ultrasound exami nations and multiple measurements of blood glucose levels were performed be tween 6 and 12 weeks of pregnancy. Pregnancies were classified into groups with normal and restricted embryonic growth according to ultrasound fetal b iometry. Differences in glycemia between groups, incidence of spontaneous a bortions and congenital malfomations were calculated. Results Early embryonic growth restriction was significantly more frequent in diabetic pregnancies. Poor maternal metabolic control in diabetic pregna ncies, measured as raised glycosylated hemoglobin level, was correlated wit h early embryonic growth restriction. The group of pregnancies with restric ted embryonic growth also showed a significantly higher incidence of sponta neous abortions, and the correlation with congenital malformations was marg inally significant. Conclusions Our results support the hypothesis that the level of maternal b lood glucose immediately prior to conception and during early embryonic dev elopment may directly affect human embryonic and consequently fetal develop ment. The number of embryopathies in diabetic pregnancies could be reduced if normoglycemia were maintained in these periods.