Friday, March 26, 2010
Research: Cesareans and the Pelvic Floor
For Childbirth Connection Enews
March 10, 2010
Nelson RL, Furner SE, Westercamp M, Farquhar C. Cesarean delivery for the prevention of anal incontinence. Cochrane Database of Systematic Reviews 2010, Issue 2. Art. No.: CD006756. DOI: 10.1002/14651858.CD006756.pub2.
Some women experience leakage of stool or gas while their perineum is healing in the postpartum period, and for some women this problem can become chronic. With age, the number of people with anal incontinence rises, and an estimated 1.4% to 11% of adults and over 50% of nursing home residents have this problem. Cesarean delivery has been proposed as a way to protect the integrity of the pelvic floor and avoid incontinence. A new systematic review explores whether cesarean section is associated with lower rates of anal incontinence than vaginal birth.
This review includes 21 observational studies that compared the odds of anal incontinence following 6,028 cesarean births with the odds of the problem following 25,170 vaginal births. No randomized controlled trials on the subject were found. The quality of the studies was assessed, and because observational studies are subject to more bias than randomized controlled trials, the authors included in their quality assessment whether the studies were prospectively designed, adjusted for maternal age, parity and delivery history, and whether incontinence was measured after 4 months postpartum when the perineum had time to heal. The studies of highest quality were also analyzed separately to see if the results differed from those of lower quality studies. No high quality studies showed any significant difference in incontinence of stool and none of the studies showed any difference in leakage of gas between women undergoing cesarean delivery and those giving birth vaginally.
This review shows no evidence that cesarean delivery protects a woman from future anal incontinence compared to vaginal birth. US cesarean rates have increased by 50% in the last decade and are currently at a record high of 31.8% as of 2007. Some have suggested that "maternal demand" cesarean section is contributing significantly to the rising rate of c-section, a practice associated with numerous increased risks when compared to vaginal birth. The authors of this review cite research that suggests avoiding incontinence is the main reason women with no medical indication for c-section elect to have their babies this way. Both of these suggestions are controversial. Just one mother out of 252 in the Listening to Mothers II survey reported that she had a first cesarean birth at her own request with no medical reason, and only one woman reported a cesarean delivery in the belief that it would help prevent future incontinence.