Vaginal birth after cesarean: a prenatal scoring tool.

Abstract

The objective of the study was to develop a tool that predicts vaginal birth after cesarean (VBAC) based exclusively on prenatal factors. This was a cohort study of 10,828 primiparous women with 1 prior cesarean, who had a subsequent delivery of a singleton term gestation. After randomizing these women to a score development or a score validation group, we investigated the association among 16 prenatal factors and trial of labor outcome, using univariate and multivariate analyses in the score development group. Factors found to be associated with VBAC were placed in a scoring tool, which was tested for reproducibility in the score validation group. The scoring tool based on 3 factors associated with VBAC showed that increasing score was associated with increased likelihood of VBAC. These results were validated. This tool may be used in early prenatal care to facilitate the decision of whether to undergo a trial of labor.