Maternal super-obesity (body mass index ≥ 50) and adverse pregnancy outcomes

Objective. To determine if pregnancy complications are increased in super-obese (a body mass index (BMI) of 50 or more) compared to other, less obese parturients. Design. Cross-sectional study. Setting and population. All 19,700 eligible women, including 425 (2.2%) super-obese women with singleton births between 1996 and 2007 delivering at a tertiary referral center, identified using a perinatal research database. Methods. Bivariate and trend analyses were used to assess the relation between super-obesity and various pregnancy complications compared to other well-established BMI categories. Adjusted odds ratios (ORs) were calculated using multivariable logistic regression techniques. Main outcome measures. Outcomes for adjusted and unadjusted analyses were small-for-gestational age (SGA) birth, large-for-gestational age (LGA) birth, preeclampsia, gestational diabetes mellitus (GDM), fetal death, preterm birth, placental abruption, cesarean delivery, and Apgar scores < 7. Results. Compared to all other obese and non-obese women, super-obese women had the highest rates of preeclampsia, GDM, LGA, and cesarean delivery (all p < 0.05 for trend test). Super-obesity was also associated with a 44% reduction in SGA compared to all other women (OR 0.55, 95% confidence interval (CI) 0.40-0.76) and a 25% reduction compared to other, less obese women (OR 0.75, 95% CI 0.54-1.03). Super-obesity was positively associated with LGA, GDM, preeclampsia, cesarean delivery, and a 5-minute Apgar score < 7 compared to all other women after controlling for important confounders. Conclusion. Super-obesity is associated with higher rates of pregnancy complications compared to women of all other BMI classes, including other obese women.