The Ipswich Childbirth Study: 2. A randomised comparison of polyglactin 910 with chromic catgut for postpartum perineal repair

Objective To compare polyglactin 910 sutures with chromic catgut sutures for postpartum perineal repair. Design A stratified randomised controlled trial, using a 2 x 2 factorial design. Setting The maternity unit at Ipswich Hospital NHS Trust, a district general hospital, between 1992 and 1994. Sample 1780 women who had sustained an episiotomy or first or second degree tear following a spontaneous or simple instrumental delivery. Methods Policies of repair with polyglactin 910 or chromic catgut were compared. Both groups were assessed by a research midwife completing questionnaires at 24 to 48 hours and at ten days postpartum, and by self-completed questionnaires at three months after birth. Main outcome measures 1. 24 to 48 hours postpartum: perineal pain, healing; 2. ten days postpartum: perineal pain, healing and removal of sutures; 3. three months postpartum: perineal pain, removal of sutures, resuturing, dyspareunia, and failure to resume pain-free intercourse. Results Completed questionnaires were returned for 99% of women at both 24 to 48 hours and ten days and by 93% of women three months postpartum. The two groups were similar at trial entry. Significantly fewer women allocated to the polyglactin 910 reported pain in the previous 24 hours at both 24 to 48 hours (59% vs 67%; RR 0.89, 95% CI 0.83-0.95; 2P < 0.01), and ten days (24% vs 29%; RR 0.81, 95% CI 0.69-0.95; 2P = 0.01). At three months postpartum there was no clear difference between the groups in terms of perineal pain, dyspareunia or failure to resume pain-free intercourse. More women in the polyglactin 910 group reported that some suture material had been removed (12% vs 7%; RR 1.62, 95% CI 1.19-2.21; 2P < 0.01). Three women in the polyglactin 910 group had required resuturing compared with ten in the chromic catgut group (RR 0.30; 95% CI 0.08-1.09; 2P = 0.1). Conclusions Using polyglactin 910 rather than chromic catgut for perineal repair leads to about one fewer women among every 20 having perineal pain and using analgesia ten days postpartum. Its only apparent disadvantage is that more women, again estimated as 1 in 20, report having material removed during healing. Data from this and other trials suggest that for every 100 women repaired with a polyglycolic acid-based material, about one fewer will require resuturing.