812: Weight gain in obese pregnant women and risk for cesarean delivery by class of obesity: pregnancy risk assessment monitoring system (PRAMS)

Abstract

To determine the influence of weight gain on the odds of cesarean delivery for obese women (as determined by pre-pregnancy body mass index [BMI]), specifically by class of obesity. This is a secondary data analysis of the Pregnancy Risk Assessment Monitoring System (PRAMS) in the United States (Centers for Disease Control and Prevention). The unadjusted odds ratios for cesarean delivery were determined for each class of BMI (underweight, normal weight, overweight, class I obesity, class II obesity, and class III obesity). These odds were then adjusted by demographic and prenatal care factors (maternal age, marital status, race, ethnicity, education) influencing either weight gain during pregnancy or risk of cesarean delivery on univariate analysis. The association of weight gain (insufficient <11 lbs, appropriate 11-20 lbs, and excessive >20 lbs) on the odds ratios of cesarean delivery in obese women was evaluated via multivariate logistic regression analysis. Thirty-two states contributed to the dataset (n=57,866 women), (Figure 1). The adjusted odds ratios (aOR) of cesarean delivery by BMI were: underweight 0.92 (95% CI 0.83, 1.01), normal weight (referent group), overweight 1.38 (95% CI 1.32, 1.45), class I obesity 1.77 (95% CI 1.68, 1.88), class II obesity 2.17 (95% CI 2.02, 2.34), and class III obesity 3.07 (95% CI 2.82, 3.34). Class I and II obese women were more likely to have a cesarean with excessive weight gain, with class I OR 1.20 (95% CI 1.06, 1.36) and class II OR 1.24 (1.04,1.48) when compared to women in their same class of obesity with appropriate weight gain (Figure 2). Although obesity is a known risk factor for cesarean delivery, this risk is thought to be mitigatable by appropriate weight gain during the pregnancy. Weight gain of <20 pounds was associated with the least risk of cesarean delivery among obese (specifically Class I and II) individuals.View Large Image Figure ViewerDownload Hi-res image Download (PPT)