Maternal and obstetrical factors associated with a successful trial of vaginal birth after cesarean section

To detect the maternal and obstetrical factors associated with successful trial of vaginal birth among women with a previous cesarean delivery.

A total of 122 women who were eligible for a trial of labor after cesarean section (TOLAC) according to departmental protocol were included in this comparative prospective study. After informed consent, the women included in this study were subjected to a thorough history to detect maternal and obstetric characteristics and a standard examination to estimate fetal weight, engagement of the fetal head, intra-partum features of fetal membranes, and cervical dilatation. After delivery, data on duration of labor, labor augmentation, mode of delivery, birth outcome, and neonatal intensive care (NICU) admission were recorded and analyzed.

Trial of labor after cesarean section was successful in 72.13% and was unsuccessful in 27.87%. Body mass index (BMI) was significantly lower in the successful TOLAC group compared to the unsuccessful group (23.8±0.03 versus 26.2±0.02 kg/m(2)), and the number of women with BMI >25 kg/m(2) was significantly high in the unsuccessful group; also, mean gestational age was significantly lower in the successful TOLAC group compared to the unsuccessful group (37.5±0.04 versus 38.5±0.03 weeks), and the number of women admitted in labor with gestation ≥40 weeks was significantly high in the unsuccessful group. The number of women admitted with >2/5 of fetal head palpable abdominally and fetal head station ≥-2 was significantly high in the unsuccessful TOLAC group.

In carefully selected cases, TOLAC is safe and often successful. Presence of BMI >25 kg/m(2), gestation ≥40 weeks, and vertex station ≥-2 were risk factors for unsuccessful TOLAC.