SAN FRANCISCO — Fecal incontinence after childbirth is a common, sometimes severe, and underrecognized problem that could be reduced with greater efforts to prevent anal sphincter ruptures, Dr. Michael P. Aronson told attendees at a conference sponsored by the Society of Gynecologic Surgeons.
Attempts to fix the damage after delivery do not work well, according to Dr. Aronson, director of women's health services at the University of Massachusetts, Worcester. Even when surgical repairs of lacerations are deemed successful, many women remain incontinent and some develop new defecatory dysfunction.
“It really matters what happens at the delivery,” he said. “If you can prevent that sphincter rupture, you can prevent a whole field of woes down the line for that patient.”
Dr. Aronson, a professor of obstetrics and gynecology, held up his own institution, a major tertiary care center, as an example of how shining a spotlight on the issue can reduce third- and fourth-degree anal sphincter lacerations.
Officials recognized that they had a problem in the summer of 2003, when the laceration rate was 8%. A year later, the rate was 6%, a reduction Dr. Aronson attributed mostly to better definitions and entering of data. Meanwhile, he noted, an education program also focused attention on the problem.
As of the spring of 2006, he reported, the rate had declined to 2.8%—better than the national standard of 3%. Defining and measuring was crucial, Dr. Aronson said, adding that “the improvement is sustainable.”
He estimated that nationwide, sphincter disruption occurs during 0.5% of vaginal births, a rate that he translated into 150,000 cases each year. If 25% of these new mothers has incontinence as a sequela, he calculated, 37,500 women are affected each year—or one new case every 14 minutes. Moreover, when incontinence occurs after sphincter rupture, he warned, symptoms increase over time.
(Anal sphincter lacerations are not the only cause of fecal incontinence, Dr. Aronson noted. Stretching the pudendal nerve during delivery can also be a contributing factor. In one study, about a third of women without a tear suffered from incontinence 5 years after giving birth.)
Dr. Aronson advocated avoiding midline episiotomy as a way of preventing anal sphincter ruptures. Numerous studies have shown it to be associated with incontinence and sphincter ruptures in up to one-fourth of patients, he said. “Midline episiotomy should be avoided if at all possible.”
Operative delivery is also significantly associated with sphincter ruptures, Dr. Aronson added. He quoted odds ratios ranging from 6.7 with forceps delivery to 2.3 with vacuum delivery.
Moreover, a history of sphincter rupture should be a serious consideration when deciding how to deliver a woman's subsequent children, according to Dr. Aronson. He warned that women who have had a third- or fourth-degree laceration are at higher risk of a new laceration in subsequent births.
Although one large cohort study of 19,000 women reported no increase with a prior history of laceration, he said, other cohort studies and a 24-year review of the Swedish Birth Registry supported increased risk. The relative risk in these studies ranged from 2.5 to 6.5.
Standard surgical repairs of anal sphincter lacerations do not heal well, Dr. Aronson continued. Ultrasound examinations have shown defect rates ranging from 79% after 3 months to 90% after the 1st week in cases that appeared to be on the mend.
“This is a tough repair,” he said. “We all know as surgeons that tension is the enemy of healing. There's tension on this right off the bat.”
When all else fails, turning the patient over to a urogynecologist or colorectal surgeon is not likely to fix the problem, Dr. Aronson added. He cited one study of successful overlapping sphincteroplasty in which 51 patients needed no further surgeries. Yet not one patient was totally continent and 14 developed new defecatory dysfunction over the next 5 years.
“Fecal incontinence is a terrible problem, much more prevalent than you know,” he said. “Our tools to fix it are not good. It is better to prevent it.”