Vaginal birth after cesarean: new insights on maternal and neonatal outcomes

To systematically review the evidence about maternal and neonatal outcomes relating to vaginal birth after cesarean (VBAC).

Relevant studies were identified from multiple searches of MEDLINE, DARE, and the Cochrane databases (1980 to September 2009) and from recent systematic reviews, reference lists, reviews, editorials, Web sites, and experts.

Inclusion criteria limited studies to the English-language and human studies conducted in the United States and developed countries specifically evaluating birth after previous cesarean delivery. Studies focusing on high-risk maternal or neonatal conditions, including breech vaginal delivery, or fewer than 10 patients were excluded. Poor-quality studies were not included in analyses.

We identified 3,134 citations and reviewed 963 articles for inclusion; 203 articles met the inclusion criteria and were quality rated. Overall rates of maternal harms were low for both trial of labor and elective repeat cesarean delivery. Although rare in both elective repeat cesarean delivery and trial of labor, maternal mortality was significantly increased for elective repeat cesarean delivery at 0.013% compared with 0.004% for trial of labor. The rates of maternal hysterectomy, hemorrhage, and transfusions did not differ significantly between trial of labor and elective repeat cesarean delivery. The rate of uterine rupture for all women with prior cesarean was 0.30%, and the risk was significantly increased for trial of labor (0.47% compared with 0.03% for elective repeat cesarean delivery). Perinatal mortality was also significantly increased for trial of labor (0.13% compared with 0.05% for elective repeat cesarean delivery).

Overall the best evidence suggests that VBAC is a reasonable choice for the majority of women. Adverse outcomes were rare for both elective repeat cesarean delivery and trial of labor. Definitive studies are lacking to identify patients who are at greatest risk for adverse outcomes.