Anal sphincter defects and anal incontinence symptoms after repair of obstetric anal sphincter lacerations in primiparous women

A study was carried out to identify (1) incidence of anal incontinence symptoms, (2) incidence and size of both external anal sphincter (EAS) and internal anal sphincter (IAS) defects, and (3) relationship between anal incontinence symptoms and IAS or EAS defect size after repair of an obstetric anal sphincter laceration. Forty-seven vaginally primiparous women underwent obstetric anal sphincter laceration repair. At 8–12 weeks postpartum, anal incontinence symptoms were assessed, and endoanal ultrasound was performed. At 1–2 years postpartum, symptoms were reassesseds. The incidence of anal incontinence symptoms at 8–12 weeks was 43%. The incidence of IAS and EAS defects were 32% and 77%, respectively. IAS defects ≥45 degrees were predictive of symptoms (p = 0.02). After 18 months mean follow-up, 11% reported chronic symptoms. After anal sphincter laceration repair, anal incontinence symptoms occur in 43% of women and remain chronic in 11%. Anal incontinence symptoms are associated with increasing IAS defect size.