Adverse perinatal outcomes associated with trial of labor after cesarean section at term in pregnancies complicated by maternal obesity.

Introduction: Obesity is associated with higher risks for intrapartum complications. Therefore, we sought to determine if trial of labor after cesarean section (TOLAC) will lead to higher maternal and neonatal complications compared to repeat cesarean section (RCD).

Methods: This was a retrospective cohort analysis of singleton nonanomalous births between 37 and 42 weeks GA complicated by maternal obesity (body mass index (BMI) ≥ 30 kg/m) and history of one or two previous cesarean deliveries. Outcomes were compared between TOLAC and RCD. The maternal outcomes of interest included blood transfusion, uterine rupture, hysterectomy, and intensive care unit admission. Neonatal outcomes of interest included 5-minute Apgar score <7, prolonged assisted ventilation, neonatal intensive care unit admission, neonatal seizures, and neonatal death.

Results: There were 538,264 pregnancies included. Compared with RCD, TOLAC was associated with an absolute increase in the following neonatal outcomes: low 5-min Apgar score (0.6%, p < .001), neonatal intensive care unit (NICU) admission (0.8%, p < .001), neonatal seizure (0.1 per 1000 births, p = .037), and neonatal death (0.2 per 1000 births, p = .028). Additionally, TOLAC was associated with an absolute increase in following maternal outcomes: blood transfusion (0.1%, p < .001), uterine rupture (0.18%, p < .001) and ICU admission (0.1%, p = .011).

Conclusions: TOLAC among obesity pregnancies at term increases the risk of maternal and neonatal complications compared with RCD.