Objective: Our purpose was to study postpartum metabolism and autoantibody markers of type 1 diabetes mellitus in women with gestational diabetes mellitus diagnosed in early pregnancy.
Study design: Thirty women with gestational diabetes diagnosed in early pregnancy were compared with 72 women who had gestational diabetes diagnosed in late pregnancy. Glucose tolerance, parameters of carbohydrate and lipid metabolism, and antibodies to glutamic acid decarboxylase and to islet cells were measured.
Results: The percentages of overt diabetes and abnormal glucose tolerance were significantly higher in the early-pregnancy group (26.7% vs 1.4%; P =.0002; and 40% vs 5.56%; P <.0001; respectively). Only 1 woman had positive test results for antibodies to the islet cells. The rate of positive test results for antibodies to glutamic acid decarboxylase was similar in both groups (13.7% vs 9.3%).
Conclusions: Women with early gestational diabetes have an increased risk of postpartum diabetes mellitus, whereas those with late-onset gestational diabetes have a minimal risk. In women predisposed to type 1 diabetes, gestational diabetes develops either early or late in pregnancy.