摘要：Objectives The purpose of this study was to evaluate the ass.c.ation between preinduction modified Bishops score and obstetric outcome, including s.c.essful vaginal birth after prior cesarean (VBAc) and uterine rupture in patients with a previous.c.sarean undergoing induction of labor. study design Medical records of all patients who had an induction of labor after a previous.c.sarean in our institution between 1988 and 2002 were reviewed. Patients were divided into 4 groups according to the modified Bishops score (0 to 2, 3 to 5, 6 to 8, and 9 to 12). The rates of s.c.essful VBAc, symptomatic uterine rupture, and other obstetric outcomes were evaluated in each group. Multivariate regression analyses were performed to adjust for confounding factors. Results Out of 685 women included in the study, 187 (27.3%) had a modified Bishops score <2, 276 (40.3%) of 3 to 5, 189 (27.6%) of 6 to 8, and 33 (4.8%) of 9 to 12. The rate of s.c.essful VBAc significantly correlated with the modified Bishops score (57.5%, 64.5%, 82.5%, and 97.0%, respectively, P <.001). However, the rate of uterine rupture was not statistically significant between the groups (2.1%, 1.8%, 0.5%, 0.0%, P=.48). After adjusting for confounding variables, a modified Bishops score ≥6 remained ass.c.ated with s.c.essful VBAc (odds ratio [OR] 2.07, 95%cI 1.28-3.35, P <..001). conclusion The modified Bishops score before induction of labor is an independent factor ass.c.ated with s.c.essful VBAc.