Incidence of uterine rupture among women with mullerian duct anomalies whoattempt vaginal birth after cesarean delivery

OBJECTIVE: The purpose of this study was to determine and compare the incid ences of uterine rupture among women with and without mullerian duct anomal ies who were attempting vaginal birth after cesarean delivery. STUDY DESIGN: There were 1813 attempts at vaginal birth after cesarean deli very between 1992 and 1997 at the Foothills Hospital in Calgary, Alberta, C anada. Of the patients 25 had known mullerian duct anomalies and 1788 did n ot. The records of these 1813 women were reviewed with respect to uterine r upture, other complications, mode of delivery, and characteristics of the t rial of labor. Comparisons were made with the Fisher exact test RESULTS: The rates of uterine rupture were 8% (2/25) in the group with mull erian duct anomalies and 0.61% (11/1788) in the group without mullerian duc t anomalies (P=.013). The cesarean delivery rates were 20% (5/25) and 25.1% (448/1788), respectively. All cesarean deliveries among women with mulleri an duct anomalies were performed urgently in response to severe fetal heart rate abnormalities. The rates of fetal heart rate abnormalities necessitat ing immediate delivery (60% vs 14.1%, P=.013), operative vaginal delivery ( 40% vs 19.6%, P=.02), and cord prolapse (8% vs 0.45%, P=.0076) were signifi cantly greater in the group with mullerian duct anomalies. CONCLUSIONS: Vaginal delivery is common among women with mullerian duct ano malies who attempt vaginal birth after cesarean delivery, but the rates of uterine rupture and other complications are high.