OBJECTIVE: The purpose of this study was to identify characteristics that may predict failure of glyburide therapy for the management of A2 gestational diabetes, and to evaluate whether those that fail are at increased risk for adverse pregnancy outcomes.

STUDY DESIGN: This was a retrospective cohort of gestational diabetics requiring medical therapy (A2DM) treated between January 2002 and July 2005.

RESULTS: Of the 235 gestational diabetics identified, 79% of the 101 A2DMs were successfully treated with glyburide as first-line therapy. Those that failed had a higher mean glucose value on glucose challenge test (GCT) (200.5 +/- 57.3 vs 176.6 +/- 33.8 mg/dL, P = .019) and were more likely to have a GCT > or = 200 mg/dL (45 vs 22%, P = .043). Only GCT and GCT > or = 200 mg/dL were predictive of failure. Those successfully managed with glyburide had increased NICU admissions, primarily for hypoglycemia and respiratory distress, which resolved prior to discharge. There was no difference in birth weight, cesarean delivery, macrosomia, or shoulder dystocia.

CONCLUSION: Predicting glyburide failure is difficult, but failure does not appear to be associated with increased adverse pregnancy outcomes.