Antenatal factors predicting subsequent need for insulin treatment in women with gestational diabetes

Objective: To identify characteristics indicative of subsequent requirement of insulin in patients with gestational diabetes (GDM). Methods: Identified from a database were patients with GDM not receiving insulin or oral hypoglycemic agents at enrollment for outpatient education and surveillance. Maternal characteristics were compared between patients achieving glycemic control with diet and those requiring insulin. Cox proportional hazards regression was used to assess multiple effects of significant univariate factors. Results: Data from 2365 patients were analyzed. Patients requiring insulin were more likely to be multiparous, obese, have a history of GDM, be diagnosed at <28 weeks of gestation, and have a fasting blood glucose of >95 mg/dL, a glucose tolerance test 3-hour blood glucose of >140 mg/dL, and a glycosylated hemoglobin (A1c) of >= 6% at diagnosis of GDM. Conclusions: Laboratory values at diagnosis of GDM were the strongest indicators of subsequent need for insulin treatment. Patients with fasting blood glucose of >95 mg/dL and A1c values >= 6% at diagnosis of GDM should receive close surveillance of daily blood glucose.