Can Preadmission Inflammatory Markers Inform Episiotomy Wound Dehiscence Risk? A Case-Control Study in Primiparous Women.

Abstract

Introduction and hypothesis: We hypothesized that routinely available preadmission inflammatory markers are associated with episiotomy wound dehiscence in primiparous women.

Methods: In this retrospective case-control study at a single tertiary centre, we reviewed primiparous women who delivered vaginally with mediolateral episiotomy between January 2021 and June 2025. We compared 51 women who developed dehiscence with 54 women with uncomplicated healing. The absolute neutrophil count and four derived markers (neutrophil-to-lymphocyte ratio [NLR], systemic immune-inflammation index, monocyte-to-lymphocyte ratio, platelet-to-lymphocyte ratio) were measured on admission to the labour ward. We used logistic regression adjusted for body mass index, model comparison by the Akaike information criterion, ROC analysis with DeLong's test, bootstrap internal validation, and multinomial regression by wound culture status.

Results: The preadmission neutrophil count was lower in women who developed dehiscence than in controls (median 5.53 vs 9.50 × 10⁹/L, p < 0.001). The neutrophil count and the NLR showed identical discrimination (AUC 0.815 each; DeLong p = 1.00), and no derived marker improved model fit beyond the neutrophil count alone. A higher neutrophil count was independently associated with lower odds of dehiscence (adjusted odds ratio 0.78, 95% CI 0.68-0.88). After bootstrapping, the optimism-corrected AUC was 0.795 with a calibration slope of 0.941. Lower neutrophil counts were associated with both culture-positive and culture-negative dehiscence.

Conclusions: In primiparous women, a lower preadmission neutrophil count was associated with episiotomy dehiscence, with the NLR acting as an equivalent proxy and no derived marker adding discriminative value. Whether this association reflects biology or the context of sampling relative to labour requires prospective confirmation.