The prevalence of 6 weeks postpartum abnormal glucose tolerance in Caucasian women with gestational diabetes.

AIMS: To evaluate the incidence of impaired glucose tolerance (IGT), impaired fasting glucose (IFG) and diabetes in 318 Caucasian women with gestational diabetes (GDM) at 6 weeks postpartum.

METHODS: All women had 75g OGTT and the following data were collected: age, height, weight, results of the challenge 50g and diagnostic 75g OGTT, and glycated hemoglobin (HbA1c).

RESULTS: 13.5% of women had abnormal glucose tolerance, including 1.3% of diabetes, 2.5% of IFG and 7.5% of IGT. None of the prepregnancy independent variables, such as age, body mass index, prior GDM, prior macrosomia, family history of type 2 diabetes and multiparity was a predictor for the abnormal OGTT. In contrast, pregnancy-related risk factors, like gestational week at GDM diagnosis (P=0.001), glucose values in the challenge (P=0.007) and diagnostic (P=0.02) OGTTs and HbA1c (P=0.01) were significantly associated with the persistence of glucose intolerance after delivery.

CONCLUSION: The incidence of postpartum abnormal glucose tolerance in Caucasian women with GDM was 13.5% and was associated with an early diagnosis of GDM, severity of hyperglycemia and requirement for insulin therapy. The diagnosis of GDM should initiate a lifelong monitoring of glucose tolerance to minimize the risk of developing overt diabetes.