Body mass index and weight gain prior to pregnancy and risk of gestational diabetes mellitus.

Abstract

The objective of the study was to evaluate obesity and rate of weight change during the 5 years before pregnancy and risk of gestational diabetes mellitus (GDM) in a nested case-control study. GDM cases (n = 251) and controls (n = 204) were selected from a multiethnic cohort of 14,235 women who delivered a live birth between 1996 and 1998. Women who gained or lost weight were compared with those with a stable weight (+/- 1.0 kg/year). Women who gained weight at a rate of 1.1 to 2.2 kg/year had a small increased risk of GDM (odds ratio [OR] 1.63 [95% confidence interval (CI) 0.95 to 2.81]) and women who gained weight at a rate of 2.3 to 10.0 kg/year had a 2.5-fold increased risk of GDM (OR 2.61 [95% CI, 1.50 to 4.57]), compared with women with stable weight (after adjusting for age, race-ethnicity, parity, and baseline body mass index). Weight gain in the 5 years before pregnancy may increase the risk of GDM.