title: Modified Bishop's score and induction of labor in patients with a previous cesarean delivery.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the association between preinduction modified Bishop's score and obstetric outcome, including successful vaginal birth after prior cesarean (VBAC) and uterine rupture in patients with a previous cesarean undergoing induction of labor.
  
  
  METHODS
  Medical records of all patients who had an induction of labor after a previous cesarean 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 successful 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 successful 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 associated with successful VBAC (odds ratio [OR] 2.07, 95% CI 1.28-3.35, P < .001).
  
  
  CONCLUSIONS
  The modified Bishop's score before induction of labor is an independent factor associated with successful VBAC.
authors.affiliation: Department of Obstetrics and Gynecology, Hôpital Ste-Justine, Université de Montréal, Montreal, Quebec, Canada. ebujold@med.wayne.edu
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Bujold
authors.forename: Sean C
authors.initials: SC
authors.lastname: Blackwell
authors.forename: Israel
authors.initials: I
authors.lastname: Hendler
authors.forename: Susan
authors.initials: S
authors.lastname: Berman
authors.forename: Yoram
authors.initials: Y
authors.lastname: Sorokin
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Gauthier
mesh_terms: D000328:Adult; D002584:Cervix Uteri / Q000473:pathology*; D005260:Female; D006801:Humans; D007751:Labor, Induced; D008499:Medical Records; D007744:Obstetric Labor Complications / Q000453:epidemiology* / Q000209:etiology; D011247:Pregnancy; D011256:Pregnancy Outcome; D012189:Retrospective Studies; D014219:Trial of Labor; D016064:Vaginal Birth after Cesarean