Objective: To estimate the prevalence of gestational weight gain adequacy according to the 2009 Institute of Medicine recommendations and examine demographic, behavioral, psychosocial, and medical characteristics associated with inadequate and excessive gain stratified by prepregnancy body mass index (BMI) category.
Methods: We used cross-sectional, population-based data on women delivering full-term (37 weeks of gestation or greater), singleton neonates in 28 states who participated in the 2010 or 2011 Pregnancy Risk Assessment Monitoring System. We estimated adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for inadequate and excessive compared with adequate gain, stratified by prepregnancy BMI.
Results: Overall, 20.9%, 32.0%, and 47.2% of women gained inadequate, adequate, and excessive gestational weight, respectively. Prepregnancy BMI was strongly associated with weight gain outside recommendations. Compared with normal-weight women (prevalence 51.8%), underweight women (4.2%) had decreased odds of excessive gain (adjusted OR 0.50, CI 0.40-0.61), whereas overweight and obese class I, II, and III (23.6%, 11.7%, 5.4%, and 3.5%, respectively) women had increased odds of excessive gain (adjusted OR range 2.07, CI 1.63-2.62 to adjusted OR 2.99, CI 2.63-3.40). Underweight and obese class II and III women had increased odds of inadequate gain (adjusted OR 1.25, CI 1.01-1.55 to 1.86, CI 1.45-2.36). Most characteristics associated with weight gain adequacy were demographic such as racial or ethnic minority status and education and varied by prepregnancy BMI. Notably, one behavioral characteristic-smoking cessation-was associated with excessive gain among normal-weight and obese women.
Conclusion: Most women gained weight outside recommendations. Understanding characteristics associated with inadequate or excessive weight gain may identify potentially at-risk women and inform much-needed interventions.