To evaluate the role of antibiotics on preventing wound complications following obstetric anal sphincter injuries (OASI).This is a cohort study with retrospective and prospective components of women who sustained an OASI at vaginal delivery. The primary objective of this study was to assess the impact of prophylactic antibiotics at the time of delivery on perineal wound complications. Women were grouped based on peripartum antibiotic administration: no antibiotics (NABX), antibiotics for OASI wound complication prophylaxis (PABX), antibiotics for therapeutic indications (TABX), and antibiotics for any indication (AABX, PABX + TABX).Four hundred and twenty-five women with OASI were included in this analysis. Most women experienced a third-degree perineal laceration (358, 84.2%). One hundred and sixteen (27.3%) women received NABX, 195 (45.9%) women received PABX, and 114 (26.8%) women received TABX. Cefazolin was the most common antibiotic in the PABX group. Perineal wound complications occurred in 51 (12.0%) women: 14 (12.4%) in NABX, 26 (13.3%) in PABX, 11 (9.6%) in TABX, and 37 (12.0%) in AABX. The incidence of perineal wound complications did not differ between groups.In this cohort study, peripartum antibiotics did not reduce wound complication incidence following OASI. It is likely that a first-generation cephalosporin is not the ideal antibiotic in this clinical setting.
