Predictors of glyburide failure in the treatment of gestational diabetes

Our objective was to identify among women with gestational diabetes mellitus (GDM) the patient characteristics that predict treatment failure with glyburide. Historical cohort of 95 GDM women offered glyburide after dietary failure with defined entry criteria. From November 2000 to May 2005, 118 women had 124 pregnancies and were offered glyburide therapy by the 2 codirectors of our Diabetes Clinic. All but 2 women elected glyburide, and 27 pregnancies were excluded due to criteria defined a priori to the study. A cohort of 95 women with 95 pregnancies were included for analysis. Nineteen percent failed glyburide. Significant predictors of failure were maternal age (34 years compared with 29 years, P = .001), earlier diagnosis of GDM (23 weeks compared with 28 weeks, P = .002), higher gravidity (P = .01) and parity (P = .03), and a higher mean fasting blood glucose (112 compared with 100 mg/dL; P = .045) compared with those successfully treated. After adjustment in the multivariable logistic regression analysis, GDM women diagnosed at a gestational age less than 25 weeks were 8.3 times more likely to fail glyburide compared with those diagnosed after 25 weeks. Maternal and fetal outcomes were favorable with a cesarean delivery rate of 25% and macrosomia rate of 7%. Glyburide was more likely to fail in women diagnosed earlier in pregnancy, of older age and multiparity, and with higher fasting glucoses, suggesting that earlier glucose intolerance and a reduced capacity to respond to an insulin secretagogue may distinguish this group. The time for glyburide as an alternative treatment has come; however, it should be prescribed after careful consideration of these patient characteristics to minimize the likelihood of failure. II-2.