Stressful events, smoking exposure and other maternal risk factors associated with gestational diabetes mellitus.

The incidence of gestational diabetes mellitus (GDM) has increased significantly in the last few decades in the US. Understanding its risk factors is imperative for the prevention of GDM and its sequelae, but the roles of behavioural risk factors such as stressful events and smoking on GDM are generally not well understood. Using data obtained from the New York State (NYS) Pregnancy Risk Assessment Monitoring System survey for 2004-06 and the NYS birth certificates, we examined relationships between GDM, stressful events and smoking among 2690 women who had live singleton births and did not have pre-pregnancy diabetes. After adjustment for risk factors such as maternal age, race/ethnicity, pre-pregnancy body mass index, hypertension, as well as smoking exposure, education, parity, and gestation at first visit for prenatal care, we found that having five or more stressful events 12 months before the baby was born was significantly associated with GDM (OR = 2.49, [95% CI 1.49, 4.16]). In another model, having any stressful event(s) other than 'moved to a new address' 12 months before the baby was born was also moderately associated with GDM (OR = 1.38, [95% CI 1.04, 1.85]). Smoking exposure, assessed by combining maternal smoking and second-hand smoke exposure into six levels, had no significant association with GDM, and did not show a dose-response pattern. The present study suggests that stressful events during pregnancy may be an independent risk factor for GDM. Future studies of GDM should include this common, but potentially modifiable risk factor in analyses.