Weight characteristics and height in relation to risk of gestational diabetes mellitus.

Increasing prevalence of overweight and obesity motivated this prospective examination of gestational diabetes mellitus in relation to self-reported adult height, weight, and weight fluctuation. Gestational diabetes was assessed by use of medical records in 1,644 women enrolled in Seattle and Tacoma, Washington, between 1996 and 2002. After adjustment, risk was inversely related to height and directly related to pregravid body mass index (p(trend) < 0.001). The relation with body mass index at age 18 years was J shaped, with higher risk among lean women (adjusted relative risk (RR) = 1.79, 95% confidence interval (CI): 1.01, 2.84) and obese women (RR = 4.53, 95% CI: 1.25, 16.43) versus normal-weight women. Weight gain between age 18 years and the study pregnancy was associated with increased risk independently of body mass index at 18 years and other confounders (>/=10-kg gain vs. <2.5-kg change: RR = 3.43, 95% CI: 1.60, 7.37). Weight cycling (loss and regain of >/=6.8 kg) was not associated after adjustment for body mass index at 18 years and adult weight change (>/=3 vs. zero cycles: RR = 1.23, 95% CI: 0.56, 2.73). Cycling was nonsignificantly related among women who gained 10 kg or more during adulthood (>/=3 vs. zero cycles: RR = 2.04, 95% CI: 0.83, 5.02). Efforts to prevent obesity and weight gain among young women may reduce gestational diabetes risk.