Prophylactic Antibiotics in Episiotomy and Second Degree Tears: Insights from the REPAIR Trial

Highlight

• The REPAIR study is a double-blind, placebo-controlled randomized trial assessing prophylactic antibiotics for episiotomy and second degree tears.
• No significant difference was found in overall wound complications between antibiotic and placebo groups.
• Clinically relevant wound complications significantly decreased with antibiotic prophylaxis (9% vs 17%; P=0.01), with a number needed to treat (NNT) of 12.
• Antibiotic use was associated with fewer additional antibiotic treatments, improved self-reported health, and smaller wound dehiscence sizes, with no serious adverse events.

Study Background

Episiotomy, a surgical incision made during childbirth to enlarge the vaginal opening, and second degree perineal tears are common obstetric injuries that can complicate postpartum recovery. These wounds carry risks of infection, delayed healing, and wound dehiscence, which may prolong discomfort and increase healthcare needs. While prophylactic antibiotics have proven beneficial in preventing infections in some surgical contexts, their routine use following episiotomy or second degree tears remains contentious due to concerns about antibiotic resistance, adverse effects, and unclear benefit magnitude. The REPAIR study was designed to address this gap by rigorously evaluating whether prophylactic antibiotic administration reduces the risk of wound complications after these common obstetric injuries.

Study Design

The REPAIR trial was conducted at a university hospital in the Capital Region of Denmark, enrolling 442 women with either episiotomies or second degree perineal tears at delivery between March and December 2023. Exclusion criteria were carefully applied to eliminate confounders, including recent antibiotic use, allergies to study drugs, non-Danish speakers, cesarean sections, and episiotomy extensions. Participants were randomized using computer-generated assignments to receive either three doses of amoxicillin (500 mg) combined with clavulanic acid (125 mg) or placebo, initiated within six hours postpartum and repeated every eight hours.

The study maintained rigorous double-blinding for participants, physicians, and the steering committee, and follow-up occurred 4 to 14 days postpartum to assess wound outcomes. The primary endpoint was overall wound complications, while a secondary endpoint focused on clinically relevant wound complications, defined presumably by severity or need for additional interventions.

Key Findings

Among 433 women completing follow-up, overall wound complications were reported in 22% of the antibiotic group compared to 29% in placebo, a difference not reaching statistical significance (P=0.10). The risk difference was -7.2% (95% CI -15.4% to 0.8%) with a relative risk of 0.75 (95% CI 0.54 to 1.04), suggesting a trend toward fewer complications but insufficient evidence to confirm a definitive overall benefit.

However, when focusing on clinically relevant wound complications—a subset likely representing infections or wound dehiscence requiring clinical intervention—the antibiotic group showed a significantly lowered incidence: 9% versus 17% in placebo (P=0.01). This corresponded to 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), indicating about a 48% reduction in clinically important wound issues with antibiotics. The calculated number needed to treat (NNT) was 12 (95% CI 7 to 56), meaning 12 women would need prophylactic antibiotics to prevent one clinically relevant wound complication.

Exploratory outcomes supported these findings, showing that women receiving prophylactic antibiotics reported better self-assessed health status, required fewer additional antibiotic treatments, and experienced less extensive wound dehiscence where it occurred. Importantly, no serious adverse events attributable to the antibiotics were reported, underscoring the safety of the intervention in this population.

Expert Commentary

The REPAIR trial provides important randomized evidence addressing a clinically significant question in obstetrical care: whether routine use of prophylactic antibiotics improves outcomes after episiotomy or second degree tears. The lack of statistically significant difference in overall wound complications may reflect the inclusion of minor and self-limited wound issues that are not clinically important. The clear reduction in clinically relevant wound complications highlights the potential targeted benefit of antibiotics in preventing serious infections or wound dehiscence.

These findings align with physiological plausibility, as perineal wounds after childbirth may be particularly susceptible to polymicrobial contamination, and prompt antimicrobial prophylaxis can potentially reduce bacterial load and inflammation, fostering improved healing. The study’s rigorous design, including rigorous blinding, minimizing bias, and robust endpoints, provides confidence in the findings.

Study limitations include its single-center design which may affect generalizability, and short-term follow-up only capturing early wound outcomes. Some populations at increased infection risk (e.g., immunocompromised, diabetes) were not separately analyzed, warranting further research. Moreover, antibiotic stewardship concerns necessitate balancing benefits against the risks of resistance and adverse effects, arguing for selective rather than universal antibiotic use.

Current obstetric guidelines vary internationally on antibiotic prophylaxis after episiotomy and perineal tears, often recommending it selectively based on clinical risk factors. The REPAIR trial supports consideration of prophylactic antibiotics as standard care in women at risk of clinically relevant wound complications, particularly where follow-up and treatment resources are accessible.

Conclusion

The REPAIR randomized controlled trial demonstrates the safety and effectiveness of prophylactic amoxicillin-clavulanic acid in reducing clinically important wound complications after episiotomy or second degree perineal tears. Although no significant benefit was seen in overall wound complications, the substantial reduction in clinically relevant infections and dehiscence suggests antibiotics should be considered as part of postpartum care to enhance wound healing and reduce morbidity. Further multicenter studies are warranted to confirm these findings, optimize patient selection, and define best practices to balance benefits with antimicrobial stewardship principles.

Funding and Trial Registration

The study was conducted without reported serious adverse events and was registered at the Clinical Trials Information System (euclinicaltrials.eu) under number 2022-501930-49-00 and at ClinicalTrials.gov (NCT05830162).

References

Perslev K, Klarskov N, Bergholt T, Jangö H. 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. BMJ. 2025 Oct 29;391:e084312. doi: 10.1136/bmj-2025-084312. PMID: 41161737; PMCID: PMC12570273.