Gestational Diabetes and Maternal Weight Management During and After Pregnancy.

Background: Women diagnosed with gestational diabetes mellitus (GDM) substantially modify their diets during pregnancy to control hyperglycemia. These changes could also affect maternal weight management. Materials and Methods: From July 2014 to December 2015 we enrolled women with and without GDM in a prospective cohort study to compare their mean rates of (1) weight gain before GDM screening, (2) weight gain after GDM screening, and (3) postpartum weight loss. All GDM-affected women were referred to Medical Nutrition Therapy and asked to self-monitor blood glucose until delivery. Rate comparisons were conducted separately for each interval using weighted t-tests and inverse probability of treatment weighting (IPTW) to account for age and prepregnancy body mass index (BMI). Linear regression models were developed to characterize the association of GDM status and rate of weight change. Results: The study included 40 women with GDM and 49 women without GDM. The IPTW analysis found that (1) women with and without GDM had similar mean rates of gestational weight gain before GDM screening (0.41 ± 0.26 kg/week vs. 0.45 ± 0.35 kg/week, respectively, p = 0.86), (2) women with GDM gained weight at a significantly lower mean rate than women without GDM following GDM screening (0.30 ± 0.28 kg/week vs. 0.53 ± 0.28 kg/week, respectively, p = 0.001), and (3) women with and without GDM had similar mean rates of postpartum weight loss (-1.37 ± 0.58 kg/week vs. -1.28 ± 0.46 kg/week, respectively, p = 0.73). The linear regression model (adjusted for age and prepregnancy BMI) demonstrated that women with GDM gained 0.19 kg/week less than women without GDM (p = 0.004) during pregnancy after GDM screening. Conclusions: In the postpartum period, women with GDM lose weight at similar rates to women without GDM despite gaining weight at significantly lower rates following GDM screening. Diagnosis and treatment of GDM may improve maternal weight management, but this benefit is limited to late pregnancy.