Abstract
Background: The prevalence of obesity among reproductive age women has increased significantly. The goal of this analysis was to determine whether gestational weight gain above the Institute of Medicine recommendation for obese women (at least 15 pounds [lbs] for term pregnancy) is predictive of postpartum weight retention at one-year.
Methods: We conducted a retrospective cohort study of 25,789 pregnancies beginning and ending between January 2000 and December 2005 in a large health maintenance organization (Kaiser Permanente, Northwest) and resulting in live birth. Obesity was defined as BMI >30 kg/m2. Total gestational weight gain (last available pre-delivery weight at pregnancy onset [−180 to +90 days]) was categorized as <0, 0–15, and >15 lbs. Postpartum weight retention (postpartum weight at one year [lowest weight measured within 243–547 days post delivery] weight at pregnancy onset) was defined as <0, 0–10, and >10 lbs, and by mean change. Descriptive, linear regression and multivariate logistic regression analyses were performed.
Results: There were 1,656 obese women who met eligibility criteria and had weights available at each key time point. Compared to women who lost weight or who gained 0–15 lbs during pregnancy, women who gained >15 lbs were younger, had lower first trimester weights and BMI, had fewer live births, and were less likely to have diabetes or depression. Mean change in weight at one-year postpartum was higher for women who gained >15 lbs during pregnancy, resulting in a net gain (7.2 lbs ± 18.6), compared to a net loss among women who either gained 015 lbs or who lost weight during pregnancy (net loss −1.7 lbs ± 6.2 and −2.3 lbs ± 16.3, respectively) (P<0.001). Total gestational weight gain was a significant predictor of weight gain at one-year postpartum (beta = 0.39, R2 = 0.11, P<0.001). Women who gained >15 lbs during pregnancy were more likely to retain >10 lbs (39.7%) at one year postpartum than women who gained 0–15 lbs (15.6%) and who lost weight (24.1%, P<0.001). There was a 3.6 fold increased odds (Odds Ratio 3.65, 95% CI 2.69–4.95) of weighing over 10 lbs more at one-year postpartum than at pregnancy onset if pregnancy weight gain was >15 lbs compared to 0–15 lbs.
Conclusion: Weight gain above 15 lbs during pregnancy is associated with significant risk of postpartum weight retention at one year among obese women. Nutritional counseling should be provided to help prevent excessive weight gain.
