195-LB: How Does a Prepregnancy Weight Loss Program Affect Gestational Diabetes Risk?

Although numerous organizations recommend that women with obesity or overweight lose weight prior to pregnancy, to our knowledge no data have addressed whether interventions that help women lose weight before pregnancy affect gestational diabetes risk in mothers. We successfully randomized 164 pregnant women to receive either a behavioral weight-loss intervention (n = 87) or usual care (n = 77) from prepregnancy through delivery. Intervention participants achieved significantly more weight loss before pregnancy than the usual care group (3.7 kg vs. 0.5 kg; p=<0.001). A diabetologist who was blinded to intervention status used EMR data to determine whether women had a clinical diagnosis of GDM. We compared rates of GDM in the intervention and usual care groups using logistic regression. Higher weight at randomization, previous GDM diagnosis, Hispanic ethnicity, and lower income were associated with higher risk of GDM. After adjusting for these variables, women in the intervention group were less likely to develop GDM (Table), although the difference was not statistically significant. However, based on our sample size of 164, we only had a power of 37% to detect the observed difference of 11% in GDM rates. Future, fully powered studies should test the role of prepregnancy weight loss interventions in preventing gestational diabetes. Disclosure E.S. LeBlanc: None. N. Smith: None. K. Vesco: None. A.G. Rosales: None. V.J. Stevens: None. Funding National Institute of Diabetes and Digestive and Kidney Diseases (R01DK0099882)