Objective: This study was undertaken to compare clinical outcomes in women with 1 versus 2 prior cesarean deliveries who attempt vaginal birth after cesarean delivery (VBAC) and also to compare clinical outcomes of women with 2 prior cesarean deliveries who attempt VBAC or opt for a repeat cesarean delivery.
Study design: We performed a secondary analysis of a retrospective cohort study, in which the medical records of more than 25,000 women with a prior cesarean delivery from 16 community and tertiary care hospitals were reviewed by trained nurse abstractors. Information on demographics, obstetric history, medical and social history, and the outcomes of the index pregnancy was obtained. Comparisons of obstetric outcomes were made between women with 1 versus 2 prior cesarean deliveries, and also between women with 2 prior cesarean deliveries who opt for VBAC attempt versus elective repeat cesarean delivery. Both bivariate and multivariate techniques were used for these comparisons.
Results: The records of 20,175 women with one previous cesarean section and 3,970 with 2 prior cesarean sections were reviewed. The rate of VBAC success was similar in women with a single prior cesarean delivery (75.5%) compared with those with 2 prior cesarean deliveries (74.6%), though the odds of major morbidity were higher in those with 2 prior cesarean deliveries (adjusted odd ratio[OR] = 1.61 95% CI 1.11-2.33). Among women with 2 prior cesarean deliveries, those who opt for a VBAC attempt had higher odds of major complications compared with those who opt for elective repeat cesarean delivery (adjusted OR = 2.26, 95% CI 1.17-4.37).
Conclusion: The likelihood of major complications is higher with a VBAC attempt in women with 2 prior cesarean deliveries compared with those with a single prior cesarean delivery. In women with 2 prior cesarean deliveries, while major complications are increased in those who attempt VBAC relative to elective repeat cesarean delivery, the absolute risk of major complications remains low.