Vaginal delivery after anal sphincter tear tied to more flatal incontinence at 3 months.(News)

MONTREAL -- Most women who choose a subsequent vaginal delivery after experiencing an anal sphincter tear during childbirth end up with an increase in "minor" fecal incontinence symptoms--namely flatal incontinence--after their next delivery, according to a Swiss study.

However, the more troubling symptoms of fecal incontinence do not worsen.

"I think, for selected women, it's reasonable to offer the option [of another vaginal delivery] because there is no evidence that this will increase their symptoms, or increase the damage to the sphincter or pudendal nerve," said Daniel Faltin, M.D., the study's author, who presented his research at the annual meeting of the International Continence Society.

"But they must be carefully counseled--and I only have data up to 3 months post partum," said Dr. Faltin, director of the Dianuro perineology center, and consultant in obstetrics and gynecology at Hopitaux Universitaires, Geneva.

In a prospective cohort analysis of 120 women with previous anal sphincter tears who chose a subsequent vaginal birth, fecal incontinence was evaluated by questionnaire in the last trimester of pregnancy and again 3 months post partum.

The women also underwent endosonography prenatally to assess the presence and importance of one or more anal sphincter defects, Dr. Faltin said.

Endosonographic findings revealed that 13% of the women had no anal sphincter defects, 17% had a defect of the internal anal sphincter, 47% had a minor external sphincter defect, and 33% of the women had a major external sphincter defect.