Early Screening and Treatment of Women with Prediabetes: A Randomized Controlled Trial

To examine whether women with prediabetes benefit from early treatment for gestational diabetes mellitus (GDM).

Women with a glycosylated hemoglobin A1C (A1C) of 5.7 to 6.4% at <14 weeks were recruited. Participants were randomized to usual care or treatment for GDM with diet, blood glucose monitoring, and insulin as needed. The primary outcome was a 75-g oral glucose tolerance test at 26 to 28 weeks. Secondary outcomes included cesarean delivery, birthweight, weight gain, and A1C change.

Between May 2012 and June 2014, 95 women were enrolled and 83 had data for analysis; 42 were randomized to treatment and 41 to usual care. The groups were similar in baseline characteristics with 40% obese. There was no difference in the primary outcome (treatment 45.2% vs. control 56.1%; relative risk [RR] 0.80; 95% confidence interval [CI] 0.53-1.24) except that women in the treatment group had a significantly lower A1C over time than women in the control group (p = 0.04). Nonobese women (n = 50) treated for GDM experienced a 50% reduction in GDM compared with controls (29.6 vs. 60.9%; RR 0.49; 95% CI 0.25-0.95).

Early treatment for women with a first-trimester A1C of 5.7 to 6.4% did not significantly reduce the risk of GDM except in nonobese women.