The natural history of clinically unrecognized anal sphincter tears over 10 years after first vaginal delivery.

OBJECTIVE

To estimate the influence of clinically unrecognized anal sphincter injuries detected by endoanal ultrasonography 3 months after first vaginal delivery on symptoms of anal incontinence over the subsequent 10-year period.

METHODS

One-hundred fifty-six consecutive primigravid women were recruited, anal endosonography performed, and bowel habit predelivery characterized by means of a validated 24-point questionnaire. After excluding four women with a clinically recognized sphincter tear after delivery and 18 who delivered by cesarean, these procedures were repeated 3 months postpartum. The questionnaire was repeated at 5 and 10 years to estimate continence change over the decade after delivery. Logistic regression was used to examine the effect of clinically unrecognized sphincter tears on continence.

RESULTS

After delivery, continence deteriorated from baseline in 37 (28%) women, eight of whom had anal sphincter tears. Continence did not deteriorate in 97 women, six of whom had anal sphincter tears. At 10 years, 59 (55%) of 107 contactable women had continence scores greater than zero, 23 of whom had deteriorated from baseline. There was a significant relationship between a sphincter tear that was symptomatic after delivery and continence deterioration sustained at 5 and 10 years (odds ratio 2.8 for change in continence score). However, no relationship was found over 10 years for those women who sustained a sphincter tear but whose continence did not deteriorate postpartum.

CONCLUSION

Ultrasonographic anal sphincter defects without postpartum incontinence are not associated with deterioration in continence over the following decade.

LEVEL OF EVIDENCE

II.