The association between trial of labor after cesarean in obese patients and adverse maternal outcomes

We hypothesized that among obese patients with a history of cesarean birth, a TOLAC is associated with decreased composite maternal adverse outcomes (CMAO) compared to planned repeat low transverse cesarean section (RLTCS).In this population-based cross-sectional study using the National Birth Certificate database from 2016 to 2020, we compared obese patients who attempted TOLAC at term (≥ 37 weeks estimated gestational age) to planned RLTCS. The primary outcome was a CMAO, defined as delivery complications, including intensive care unit (ICU) admission, uterine rupture, unplanned hysterectomy, or maternal blood transfusion.Overall, 794,278 patients met inclusion criteria for the study; 126,809 underwent a TOLAC, and 667,469 had a planned RLTCS. The overall CMAO was significantly higher for patients undergoing TOLAC (9.0 per 1000 live births) compared to RLTCS (5.3 per 1000 live births; aRR 1.64, 95% CI 1.53-1.75).This data demonstrate that in obese patients with prior cesarean birth, a trial of labor is associated with increased maternal morbidity when compared to a planned repeat cesarean birth.