Predicting the need for medical therapy in patients with mild gestational diabetes

The enforcement of a one-step gestational diabetes mellitus (GDM) diagnosis would capture more patients with milder forms of glucose intolerance thereby increasing the incidence. We propose to identify characteristics predicting the need for medical therapy in such patients.

Retrospective chart review of patients with mild GDM, defined as a fasting plasma glucose (FPG) < 95 mg/dL on the 3-hour 100-g oral glucose tolerance test (OGTT). Patients requiring medical therapy for glucose control were compared with diet-controlled patients. A predictive model was constructed with variables of significance.

Included were 143 patients requiring medical therapy and 224 diet-treated patients. Mean FPG on 3-hour OGTT, prepregnancy body mass index (BMI), and BMI at 26 to 30 weeks were all significantly higher in patients requiring therapy. Combining several variables produced a predictive model with 76% sensitivity, 52% specificity, 48% positive predictive value, and 78% negative predictive value.

Antenatal factors (alone or in combination) do not allow for prediction of the possible need for therapy in mild GDM patients.