Vaginal Delivery Associated With Increased Risk of Pelvic Floor Dysfunction

Emma Hitt, PhD

September 16, 2005

Sept. 16, 2005 (Atlanta) -- Vaginal delivery but not pregnancy appears to be associated with an increased risk of pelvic floor dysfunction (PFD), a new study suggests.

Although pregnancy and delivery have been previously implicated in the development of PFD, most studies have failed to control for the route of delivery. In their study, Emily Lukacz, MD, from the University of California, San Diego, and colleagues in collaboration with Kaiser Permanente of Southern California evaluated whether giving birth only by cesarean section is associated with a decreased risk of PFD compared with women who deliver vaginally.

They presented their findings here at the 26th annual meeting of the American Urogynecologic Society.

The Epidemiology of Prolapse and Incontinence Questionnaire (EPIQ) was mailed to more than 12,000 women, and of those, 4,458 responded (37%), and 4,103 had sufficient information to analyze. The mean age of the respondents was 57 years (range, 25-84 years).

Symptoms of PFD evaluated by the survey included stress urinary incontinence, overactive bladder, mixed urinary incontinence, anal incontinence, and pelvic organ prolapse. On the basis of their responses to the questions and their reported degree of bother, the women were identified as positive or negative for PFD.

The women were classified into three groups: those who had not given birth (nulliparous; n = 787), those who had delivered by vaginal birth (n = 2,927), and those who had delivered by cesarean section only (n = 389). The median number of births in both the vaginal and cesarean delivery groups was two.

The adjusted odds ratio between women who had delivered vaginally vs those who delivered via cesarean section was 1.85 (95% confidence interval [CI], 1.42 - 2.41; P < .05), a nearly twofold increased risk of PFD among those patients delivering vaginally compared with those delivering by cesarean section.

By contrast, the adjusted odds ratio for PFD in the cesarean group vs the nulliparous group was 0.92 (95% CI, 0.69 - 1.24; P < .05), indicating that pregnancy itself did not increase the risk of PFD. For the vaginal delivery vs the nulliparous group, the adjusted odds ratio was 1.76 (95% CI, 1.46 - 2.12; P < .05).

The researchers reported that the risk of all five conditions of PFD was increased significantly in the vaginal delivery group compared with the cesarean delivery group. By contrast, the rate of these symptoms was similar among those women who had delivered by cesarean section or who were nulliparous.

Of the respondents, 37% had one or more conditions associated with PFD. However, 42% of women who had delivered vaginally had one or more of the conditions compared with 27% of women in both the cesarean and nulliparous groups ( P < .05).

In addition, pelvic organ prolapse was significantly more common among patients in the cesarean group who underwent labor (n = 199) compared with those who did not (n = 93; P = .043).

Dr. Lukacz pointed out that as with any cross-sectional survey, the findings are subject to responder bias, and that only an association was established rather than cause and effect.

She also told Medscape that their findings in favor of cesarean section are likely to be controversial among advocates of vaginal births.

"The findings are merely meant to provide information for clinicians about the risk of vaginal vs cesarean delivery," she said. "We determined that as many as seven cesarean sections would have to be performed to prevent one case of PFD, so clearly, the protective effects of cesarean section must be balanced against known risks of surgical delivery."

Dr. Lukacz added that prospective studies are needed to confirm these findings, but "for now, we are able to tell women that the risk of PFD does appear to be increased with vaginal delivery."

AUGS 26th Annual Scientific Meeting: Paper 3. Presented Sept. 15, 2005.

Reviewed by Gary D. Vogin, MD


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.