Does Cesarean Delivery Prevent Anal Incontinence?

Abstract & Commentary

Synopsis: Severe anal incontinence occurs after elective cesarean delivery as well as vaginal delivery, suggesting that pregnancy itself may lead to pelvic floor disorders.

Source: Lal M, et al. Obstet Gynecol. 2003;101: 305-312.

Researchers from the United Kingdom compared the incidence and severity of anal incontinence after cesarean and vaginal delivery among primiparous patients. Nine months after delivery, primiparas received letters inviting them to participate, followed by telephone interviews and ultimately a validated questionnaire, the "Birmingham Bowel and Bladder Questionnaire." Ultimately 184 patients were interviewed (100 vaginal deliveries, 104 emergency cesareans, and 80 elective cesareans). Anal incontinence first occurred in 8% after vaginal delivery and 5% after cesarean delivery (RR, 0.611; 95% CI, 0.25-1.53). Severe cases, requiring use of a pad, affected 2 patients after vaginal delivery and 1 after cesarean delivery. Among 22 patients with a second-degree tear, 23% had new anal incontinence compared with 3% among mothers with an intact perineum. Because anal incontinence appeared after both cesarean and vaginal delivery and because severe anal incontinence followed both elective and pre-labor emergency cesarean delivery, the role of pregnancy itself should also be considered when searching for a cause of new anal incontinence. Lal and colleagues recommend that postpartum anal incontinence should be a consideration in all women who have delivered, including those who had cesarean delivery.

Comment by Frank W. Ling, MD

The title of the article is right on target. This is a question that all of us who deliver babies and see the mothers postpartum have struggled with. How many times have we tried to explain to a patient what effect the vaginal delivery had on their postpartum anal incontinence? What about the use of operative intervention, whether vaginal or abdominal? Couldn’t a cesarean have prevented this outcome? Vaginal delivery may lead to anal incontinence by way of pudendal neuropathy or direct trauma to the anal sphincter, but the role of cesarean delivery is unclear. Two studies question whether emergency cesarean delivery is protective against anal incontinence.1,2

This study population comes from a single institution, is 95% white, and all the episiotomies were mediolateral. The incidence of anal incontinence following vaginal delivery is comparable to the literature, but the finding that elective cesarean and prelabor emergency cesarean are not always protective against anal incontinence is significant. Although this study is somewhat limited by recall bias, focusing on primiparous patients minimizes this concern. An additional finding that should not be lost is the relationship between second-degree tears and subsequent anal incontinence. Anal ultrasound was not used to document the degree of damage, thereby reducing the reliability of these findings.

So what’s the point? I believe that the "take home message" is we should not counsel our patients that cesarean delivery will invariably protect the pelvic floor. Pregnancy itself may, in some cases, be the culprit in subsequent anal incontinence. Decisions regarding mode of delivery should not be inappropriately optimistic relative to future problems. Patients complaining of incontinence after cesarean delivery should be evaluated as completely as after a vaginal delivery. This article does add a few brushstrokes to an increasingly complex painting.

Dr. Ling is UT Medical Group Professor and Chair, Department of Obstetrics and Gynecology, University of Tennessee Health Science Center, Memphis, TN.

References

1. MacArthur C, et al. Br J Obstet Gynaecol. 1997;104: 46-50.

2. Fynes M, et al. Obstet Gynecol. 1998;92:496-500.