Outcome of trial of labor after cesarean section in women with past failed operative vaginal delivery

OBJECTIVE: The objective of the study was to assess the outcome of trial of labor after cesarean (TOLAC) in women with past failed operative vaginal delivery (OVD). STUDY DESIGN: A retrospective study of all women who underwent cesarean section (CS) because of a failed OVD in a tertiary medical center between 1996 and 2011. Women who had a subsequent delivery were identified, and the outcome of subsequent delivery was analyzed. RESULTS: Overall, 533 women underwent CS because of failed OVD during the study period. A total of 204 women (38.3%) had a subsequent delivery, of whom 93 (45.6%) had a TOLAC and 111 (54.4%) had a repeat elective CS. The success rate in the TOLAC group was 61.3% (n = 57). The most common indication for repeat CS was lack of progress (72.3%) among the 36 women in whom TOLAC failed (38.7%). The rate of postpartum hemorrhage and prolonged maternal hospitalization was lower in the TOLAC group than in the repeat CS group (2.2% vs 10.8%, P = .02, and 0% vs 8.1%, P = .005). There were no cases of rupture or dehiscence of the uterine scar. Factors associated with failed TOLAC were the occiput-posterior position and prolonged the second stage as the indication for OVD in the index pregnancy, maternal age older than 30 years at the time of subsequent delivery, and a birthweight in the subsequent pregnancy that is higher than the birthweight in the index pregnancy. CONCLUSION: TOLAC in women who underwent a previous CS because of a failed OVD is associated with a relatively high success rate compared with the reported success rates among women with past CS during the second stage of labor. This information and the risk factors for TOLAC failure can be used when counseling these women regarding mode of delivery in subsequent pregnancy.