Objective To estimate the association between maternal super obesity (body mass index [BMI] ≥ 50 kg/m2) and neonatal morbidity among neonates born via cesarean delivery (CD). Methods Retrospective cohort of singleton neonates delivered via CD ≥ 37 weeks in the Maternal-Fetal Medicine Unit Cesarean Registry. Maternal BMI at delivery was stratified as 18.5 to 29.9 kg/m2, 30 to 39.9 kg/m2, 40 to 49.9 kg/m2, and ≥ 50 kg/m2. Primary outcomes included acute (5-minute Apgar score < 5, cardiopulmonary resuscitation and ventilator support < 24 hours, neonatal injury, and/or transient tachypnea of the newborn) and severe (grade 3 or 4 intraventricular hemorrhage, necrotizing enterocolitis, seizure, respiratory distress syndrome, hypoxic ischemic encephalopathy, meconium aspiration, ventilator support ≥ 2 days, sepsis and/or neonatal death) neonatal morbidity. Odds of neonatal morbidity were estimated for each BMI category adjusting for clinical and operative characteristics. Results Of 41,262 maternal-neonatal dyads, 36% of women were nonobese, 49% had BMI of 30 to 39.9 kg/m2, 12% had BMI of 40 to 49.9 kg/m2, and 3% were super obese. Compared with nonobese women, super obese women had twofold odds of acute (5 vs. 10%; adjusted odds ratio [aOR]: 1.81, 95% confidence interval [CI]: 1.59-2.73) and severe (3 vs. 6%; aOR: 2.08; 95% CI: 1.59-2.73) neonatal morbidity. Conclusion Among term infants delivered via CD, maternal super obesity is associated with increased risk of neonatal morbidity
