Uterine rupture in patients with a prior cesarean delivery: the impact of cervical ripening.

The purpose of this study was to examine factors that were associated with uterine rupture in patients attempting vaginal birth after cesarean delivery. We analyzed the results of all patients attempting vaginal birth after cesarean delivery between September 1996 to December 1999 at a single institution using a contemporaneously maintained registry. Maternal factors, fetal factors, and management of labor were all assessed to determine the risk factors associated with symptomatic uterine rupture at the time of attempted vaginal birth after cesarean delivery. Twenty-eight symptomatic ruptures were identified in 972 attempts of vaginal birth after cesarean delivery at a gestational age greater than 24 weeks (2.88%). The use of preinduction cervical ripening was significantly associated with an increased risk of symptomatic uterine rupture (odds ratio, 3.92; 95% confidence interval, 1.78 to 8.62). Patients who underwent preinduction cervical ripening were significantly less likely to delivery vaginally than women who had not (46.71 versus 76.87%; p < 0.001). No other differences were noted between the two groups. Preinduction cervical ripening is associated with an increased risk of uterine rupture in women attempting vaginal birth after cesarean delivery.