Elective cesarean delivery for women with a previous anal sphincter rupture

OBJECTIVE: The purpose of this study was to evaluate elective cesarean delivery for women with a history of anal sphincter rupture. STUDY DESIGN: The effectiveness of cesarean delivery in parous women with a previous anal sphincter rupture was determined by decision analysis. The outcomes were excess cesarean deliveries and morbidity and mortality rates per prevented case of anal incontinence. RESULTS: We needed 2.3 cesarean deliveries to prevent one case of anal incontinence. A woman who chooses a cesarean delivery has a 11.3% risk of morbidity compared with a 4.2% risk for vaginal delivery (relative risk, 2.7; 95% CI, 2.6-2.8; P < .001). The relative risk for maternal death from a cesarean delivery is 2.6 (95% CI, 1.5-4.5; P < .001). CONCLUSION: Continent women with a previous anal sphincter rupture who are delivered vaginally are at high risk for permanent anal incontinence. Cesarean delivery will prevent most cases of anal incontinence, although marginally increasing maternal risk. The increased risk may be justified by the potential benefits. Patients should be counseled on these risks and benefits.