Is Normal Delivery Possible after a cesarean?

What does the best available evidence tell us about vaginal birth after two cesareans?

Tahseen S, Griffiths M. Vaginal birth after two caesarean sections (VBAC-2) - A systematic review with meta-analysis of success rate and adverse outcomes of VBAC-2 versus VBAC-1 and repeat (third) caesarean sections. BJOG 2010;117(1):5 -19.

The practice of vaginal birth after cesarean (VBAC) has swung widely over the past two decades, declining considerably since 1997 due in large part to concern about increased risk of uterine rupture. A recent consensus conference convened by the National Institutes of Health to study the evidence and provide guidance on VBAC concluded that “trial of labor is a reasonable option for many pregnant women with one prior low transverse uterine incision.”

In this study, the authors conducted a careful meta-analysis to pool all available observational data on the success rate and risks associated with vaginal birth after two cesareans, comparing this to vaginal birth after only one cesarean and also with elective repeat cesarean. The pooled successful VBAC rate among 5666 women who had a trial of labor after two or more cesareans was 71.7% (compared to 76.5% after one cesarean). The pooled uterine rupture rate after more than one cesarean was 1.36%, which represents a statistically significant increase in relative risk, but a very small increase in absolute risk for this rare complication. Importantly, the study did not indicate a significant difference in risk of neonatal death, asphyxia, or admission to the neonatal intensive care unit among VBAC after one cesarean, VBAC after more than one cesarean, or elective repeat cesarean. In addition, the rate of other serious maternal complications such as hysterectomy, blood transfusion, or fever was not significantly greater for VBAC after more than one cesarean than for elective repeat surgery.

The take-away: The authors conclude that this analysis of best available data does not suggest excessive risk associated with VBAC after two prior cesarean births, and therefore eligible women should be appropriately counseled and offered the option to undergo a trial of labor.