The role of maternal body mass index in outcomes of vaginal births after cesarean

Objective To evaluate the association between maternal body mass index and obstetrical outcome in patients with a prior cesarean undergoing a trial of labor versus elective repeat cesarean. Study design A perinatal database between 1991 and 1997 was used to identify secundipara at term after a previous cesarean section. In different groups according to maternal body mass index, the rates of successful vaginal birth after caesarean, uterine scar separation, and other obstetrical outcomes were evaluated. Results Of 8580 patients with a prior cesarean, 1862 (21.7%) underwent an elective repeat cesarean and 6718 (78.3%) underwent a trial of labor. Maternal body mass index correlated inversely with the rate of successful vaginal birth after caesarean but not with the rate of uterine scar separation. After adjustment for confounding factors including maternal age, birth weight, induction of labor, and preeclampsia, maternal body mass index remained associated with a lower rate of successful vaginal birth after cesarean. Conclusion Maternal body mass index is an independent factor associated with a lower rate of successful vaginal birth after cesarean.