Risk of infection and wound dehiscence after use of prophylactic antibiotics in episiotomy or second degree tear (REPAIR study): single centre, double blind, placebo controlled randomised trial

OBJECTIVE To evaluate the effect of prophylactic antibiotics on the risk of wound complications after episiotomy or second degree tear. DESIGN Single centre, double blind, placebo controlled randomised trial. SETTING One university hospital in the Capital Region of Denmark. Participants were enrolled between March and December 2023. All initial clinical consultations were conducted between March 2023 and January 2024, and all long term follow-up consultations were conducted between March and November 2024. This article reports only data from the first consultation. PARTICIPANTS 442 women with episiotomies or second degree tears were consecutively recruited at delivery. Exclusion criteria included treatment allergy (or risk of cross reactivity with related antibiotics), antibiotic use within 24 hours of delivery, non-Danish speakers, caesarean section, or episiotomy extension. INTERVENTION A computer generated program randomised participants to either three doses of amoxicillin (500 mg) with clavulanic acid (125 mg) or placebo starting within six hours post partum and repeated at eight hour intervals. Follow-up was conducted four to 14 days post partum. Physicians, the steering committee, and participants were blinded. MAIN OUTCOME MEASURES Wound complications (primary outcome) and clinically relevant wound complications (secondary outcome). RESULTS The study ended as planned, in December 2024. 433 women completed follow-up and were included in the primary analysis. No significant difference was observed in overall wound complications (antibiotic 47/218, 22%; placebo 62/215, 29%; P=0.10), with a risk difference of −7.2% (95% confidence interval (CI) −15.4% to 0.8%) and a relative risk of 0.75 (0.54 to 1.04). For clinically relevant wound complications, significantly fewer events occurred in the treatment group (19/218, 9% v 36/215, 17%; P=0.01), with a risk difference of −8.0% (95% CI −14.3% to −1.8%) and a relative risk of 0.52 (0.31 to 0.88). For clinically relevant wound complications, the number needed to treat was 12 (95% CI 7 to 56). Exploratory outcomes show that the treatment group reported better self-evaluated health, received fewer additional antibiotic treatments, and had smaller average wound dehiscence among patients with dehiscence. No serious adverse reactions occurred. CONCLUSION Although no significant effect was seen for overall wound complications, prophylactic antibiotics significantly reduced the risk of clinically relevant wound complications in women with episiotomies and second degree tears and should be considered in postpartum care.