Vaginal birth after cesarean (VBAC) attempt in twin pregnancies: is it safe?

OBJECTIVE: The purpose of this study was to compare the rate of vaginal birth after cesarean (VBAC) attempt, VBAC failure, and major maternal adverse outcomes in women with a previous cesarean with twin or singleton pregnancies.

STUDY DESIGN: This was a multicenter retrospective cohort study between the years 1996 and 2000. Subjects were identified by ICD-9 code. Trained research nurses collected medical record data on the outcome of VBAC attempts, and clinical outcomes, including uterine rupture and major operative injuries. We used bivariate and multivariable techniques to assess the association between twins and the outcomes.

RESULTS: Of 25,005 patients with at least 1 previous cesarean, there were 535 twin pregnancies and 24,307 singleton pregnancies. Compared with patients with singleton gestations, patients with twins were less likely to attempt a VBAC (adjusted odds ratio [AOR] 0.3, 95% CI 0.2-0.4), but no more likely to have a VBAC failure (AOR 1.1, 95% CI 0.8-1.6), a uterine rupture (AOR 1.2, 95% CI 0.3-4.6), or a major maternal morbidity (AOR 1.6, 95% CI 0.7-3.7).

CONCLUSION: Women with twin gestations are less likely to attempt a VBAC, but they are no more likely to fail a VBAC trial or experience a major morbid event compared with women with singleton gestations.