The objective of this study is to determine the influence of weight gain on the odds of cesarean delivery for obese women (as determined by pre-pregnancy BMI), by class of obesity.
Materials and Methods:
This is a secondary data analysis of the Pregnancy Risk Assessment Monitoring System (PRAMS) in the United States. Specifically, the unadjusted odds of 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 influencing either weight gain during pregnancy or risk of cesarean delivery. Finally, the association of weight gain (insufficientlbs, appropriate 11-20 lbs, and excessive >20 lbs) on the odds of cesarean delivery was noted via multivariate logistic regression analysis.
The adjusted odds of cesarean delivery by BMI are noted: 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 are more likely to have a cesarean with excessive weight gain, with class I odds ratio 1.20 (95% CI 1.06, 1.36) and class II odds ratio 1.24 (1.04,1.48) when compared to women in their same class of obesity with adequate weight gain.
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 11-20 pounds was associated with the least risk of cesarean delivery among obese (particularly Class I and II) individuals.
McCurdy, Rebekah Jo, "Weight Gain in Obese Pregnant Women and Risk for Cesarean Delivery by Class of Obesity" (2017). Master of Public Health Capstone Presentations. Presentation 213.