Wound Complications After Obstetric Anal Sphincter Injuries

OBJECTIVE: To estimate the incidence of and risk factors for wound complications in women who sustain obstetric anal sphincter injuries. METHODS: This was a prospective cohort study of women who sustained obstetric anal sphincter injuries during delivery of a full-term neonate between September 2011 and August 2013. Women were seen in the urogynecology clinic within 1 week of delivery and at 2, 6, and 12 weeks postpartum for perineal wound assessment. A visual analog scale for pain was administered at each visit. RESULTS: Five hundred two women met inclusion criteria for the study, and, ultimately, 268 women (54%) were enrolled. Eighty-seven percent of the cohort was nulliparous and 81% had a third-degree laceration. The majority (n=194) underwent an operative vaginal delivery (66.0% forceps and 6.0% vacuum). The overall risk was 19.8% (95% confidence interval [CI] 15.2-25.1%) for wound infection (n=53) and 24.6% (95% CI 19.6-30.2%) for wound breakdown (n=66). Operative vaginal delivery was associated with wound complications (infection, breakdown, or both) (adjusted odds ratio [OR] 2.54, 95% CI 1.32-4.87, P=.008). Intrapartum antibiotic therapy for obstetric indications was associated with a decreased risk of wound complications (adjusted OR 0.50, 95% CI 0.27-0.94, P=.03). Women with a wound complication reported significantly more pain within 1 week of delivery than women with a normally healing perineum (visual analog scale: 40.1 +/- 25.6 compared with 31.0 +/- 23, P=.002); this persisted at 12 weeks postpartum (6.6 +/- 7.5 compared with 3.4 +/- 7.1, P=.005). CONCLUSION: Women who sustain obstetric anal sphincter injuries are at high risk for the development of wound complications in the early postpartum period, warranting immediate and consistent follow-up.