INCIDENCE OF 3RD-DEGREE PERINEAL TEARS IN LABOR AND OUTCOME AFTER PRIMARY REPAIR

The incidence and outcome of third-degree tears following 16 583 vagin al deliveries were prospectively assessed over a 5.5-year period. Nine ty-three deliveries (0.56 per cent) were complicated by a third-degree tear and the patients underwent primary repair. Eighty-one patients w ere reviewed 3 months postpartum at a colorectal clinic. Third-degree tears were significantly more common in primigravidae and mothers with higher birth-weight babies. They were significantly associated with t he use of forceps and were not prevented by episiotomy. Of the 81 pati ents reviewed, 30 had an abnormal anorectal examination. Six patients (7 per cent) were incontinent of faeces, A further ten (12 per cent) w ere incontinent of flatus only. The overall incidence of faecal incont inence was 0.04 per cent. An important group of women with significant subclinical sphincter injury was identified. Obstetric trauma causes significant anorectal dysfunction and patients with third-degree tears require assessment by a colorectal specialist.