Superobesity and Pregnancy Outcomes

Obesity is associated with increased maternal and fetal morbidity. Super obesity (BMI ≥ 50) is associated with even higher complication rates. The Institute of medicine (IOM) recommends a weight gain of 11-20 pounds for class 3 obesity (BMI > 40). Our primary outcome was whether pregnancy outcomes varied based on total weight gain. We hypothesized that high weight gain was associated with the most complications. Retrospective cohort study of deliveries in our institutional database from June 2002 till April 2020. Eligible patients had an available pre-pregnancy BMI that was ≥ 50kg/m2, a singleton pregnancy, and total weight gain recorded. Pre pregnancy BMI was obtained in the 6 months preceding pregnancy, during the first trimester, or self-reported. Subjects were stratified into 4 weight categories: No weight gain/weight loss, 1-10 pounds, 11-20 pounds and > 20 pounds weight gain. (Groups 1, 2, 3 and 4) Data was analyzed using the Kruskal- Wallis H and Chi square tests with alpha set at 0.05 for significance. 483 subjects were identified with a delivery BMI of ≥ 50. Groups 1-4 included 89, 113, 93 and 188 patients, respectively. 73.7% were parous, 65.1% were non-Hispanic Black, 43.5% had chronic hypertension, and 10.1% had pre-existing diabetes. 38.9% of patients gained above IOM recommendation of 20 pounds. There was no difference in the incidence of neonatal morbidity, maternal comorbidity or pregnancy complications between groups. Birth weight was statistically different with higher birth weights associated with higher weight gain (P< 0.01). With group 3 (11-20 pounds weight gain) being the reference group, the relative risks of pregnancy and neonatal complications showed no consistent trend across weight categories (Table 1). Pregnancy and neonatal outcomes in super obese patients appear to be independent of weight gain or loss during pregnancy, with the exception of infant birth weight.