Obstetric sphincter tears and anal incontinence: an observational follow-up study

Background. Persistent defects after primary sphincter repair and occult sphincter tears are common after vaginal deliveries. Anal incontinence may be associated with these morphological defects. Material and methods. Forty-six primiparous women were evaluated with ultrasonography, manometry and electrophysiology. Twenty-four women had undergone primary repair of obstetric sphincter tears (sphincter group), 16 women had no clinical sphincter tear but developed anal incontinence postpartum (symptom group), and six were delivered by elective cesarean section (cesarean group). Results. In the sphincter group, 50% had anal incontinence at follow-up. At ultrasonography, 70% had injuries anteriorly in the midanal canal. At manometry, 4% had decreased resting pressure and 50% decreased squeeze pressure. At electrophysiology, 19% had pathologic pudendal latency and 25% pathologic fiber density. In the symptom group, 44% had injuries anteriorly in the midanal canal at ultrasonography. At manometry, all women had n...