Risk factors for wound complications after second-degree tears or episiotomy - a secondary analysis of the REPAIR...

Risk factors for perineal wound complications have primarily been studied in women with obstetric anal sphincter injuries, whereas data in women with second-degree tears and episiotomy are limited.

To identify risk factors for clinically relevant wound complications following second-degree perineal tear or episiotomy. We hypothesized that obstetric and repair-related factors would be associated with an increased risk of wound complications.

This cohort study was based on data from a randomized controlled trial conducted at a university hospital in the Capital Region of Denmark from March to December 2023. A total of 442 women with second-degree perineal tears or episiotomy were included and randomized to prophylactic antibiotics or placebo. For this secondary analysis, participants were analyzed as a single cohort. Candidate variables were selected based on prior literature and clinical relevance. Multivariable logistic regression was performed, and results are presented as adjusted odds ratios with 95% confidence intervals.

Out of the 442 women in the study, 433 came for the initial consultation, of whom 55 (12.7%) had a clinically relevant wound complication. Prolonged active second stage of labor (adjusted odds ratio 2.25, 95% confidence interval 1.11 to 4.46) and deep tear (adjusted odds ratio 2.11, 95% confidence interval 1.10 to 4.24) were associated with increased risk of wound complications. Doctor involvement in suturing was also associated with the outcome (adjusted odds ratio 2.47, 95% confidence interval 1.20 to 4.96). Prophylactic amoxicillin-clavulanic acid reduced the risk of wound complications (adjusted odds ratio 0.34, 95% confidence interval 0.18 to 0.65). Episiotomy was not independently associated with the outcome in adjusted analysis (adjusted odds ratio 2.01, 95% confidence interval 0.92 to 4.21) but was retained in the model because it remained borderline associated with the outcome and has consistently been identified as a relevant risk factor in previous studies.

In this exploratory analysis, prolonged active second stage of labor and deep tear were associated with increased risk of wound complications. Doctor involvement in suturing was also associated with the outcome, although this finding may reflect residual confounding by tear complexity. Prophylactic antibiotics were protective. These findings may support targeted postpartum follow-up in high-risk women.