846: Neonatal outcomes by planned mode of delivery in morbidly obese women with prior cesarean section

Abstract

To compare neonatal outcomes of women with class II-III obesity and prior cesarean delivery who underwent a trial of labor after cesarean (TOLAC) with those who underwent repeat planned cesarean delivery. We performed a retrospective cohort study of all women class II-III obesity (body mass index >35 kg/m2) and prior cesarean delivery who had a singleton birth at 38-42 weeks of gestation in Ontario, Canada between April 2012 and March 2014. Data were obtained from the Better Outcomes Registry & Network (BORN) Ontario, BORN Information System (BIS) database. Women who were not candidates for a TOLAC were excluded. Neonatal outcomes of women who had a TOLAC were compared to that of women who underwent a planned repeat cesarean delivery. The primary neonatal outcome was a composite of any of the following: intrapartum neonatal death, neonatal intensive care unit admission, 5-minutes Apgar score <7, and umbilical artery pH < 7.1. Odds ratios and 95% confidence intervals were adjusted for maternal age, parity, BMI, labor induction, pre- gestational diabetes, type of anesthesia, gestational age at delivery, birth weight <10th percentile, newborn sex and academic center. 1) Of 281,480 women who gave birth during the study period, 2,337 (0.8%) met enrollment criteria; 458 (19.6%) had a TOLAC and 1,879 (80.4%) had a planned repeat cesarean delivery (Figure). 2) Of the women who underwent a TOLAC, 153 (33.4%) had an intrapartum cesarean delivery. 3) The rate of primary neonatal outcome was similar between the TOLAC and the planned repeat cesarean delivery groups (16.8% vs. 14.1%, p=0.13). 4) When stratifying outcomes by actual (rather than planned) mode of delivery, a successful TOLAC was not associated with lower or higher odds of primary neonatal outcome (adjOR 0.97, 95%-CI 0.62-1.53) while a failed TOLAC was associated with higher odds of primary neonatal outcome (adjOR 1.77, 95%-CI 1.06-2.95) compared with women who underwent planned cesarean delivery. In pregnant women with class II-III obesity between 38-42 weeks of gestation, with prior cesarean section, neonatal outcome is not affected by the planned mode of delivery, although the risk of adverse neonatal outcomes is highest among women who have failed TOLAC.