Clinical predictors of postpartum vaginal and vulvar hematomas and the need for surgical treatment

To identify risk factors for postpartum vaginal or vulvar hematoma and to determine clinical predictors of surgical intervention.

A retrospective matched case-control study was conducted at a tertiary, university-affiliated center (2012-2024). Women diagnosed with vaginal or vulvar hematoma (cases) during the postpartum hospitalization were matched in a 1:3 ratio by maternal and gestational age to controls. Independent risk factors were identified using conditional logistic regression with a Cox regression model. A risk score was derived from the multivariable model, and ROC analysis was used to assess performance. A subgroup analysis evaluated predictors of surgery.

Among 147,045 deliveries, 57 women (0.04%) had postpartum hematoma; 170 matched controls were included. Mean diagnosis time was 1.0 ± 1.6 days post-partum. Hematoma was associated with vacuum-assisted delivery (21.1% vs. 4.7%, p < 0.001), episiotomy (24.6% vs. 2.4%, p < 0.001), second-degree laceration (38.6% vs. 15.3%, p < 0.001), nulliparity, and lower body mass index (BMI; p < 0.001). In multivariable analysis, episiotomy (odds ratio [OR] 35.9, 95% confidence interval [CI] 5.6-232.4), second-degree laceration (OR 10.3, 95% CI 3.2-32.9), and vacuum delivery (OR 5.0, 95% CI 1.0-24.5) independently increased risk, whereas higher BMI (OR 0.69/unit, 95% CI 0.55-0.85) and epidural analgesia (OR 0.33, 95% CI 0.12-0.93) were protective. The model's AUC was 0.83; a score ≥3 yielded 68% sensitivity and 79% specificity and a 97.8% negative predictive value, supporting its utility in ruling out hematoma and reducing surgical interventions. Among women with a hematoma, 26.3% required surgery. Mean time to surgery from diagnosis averaged 6.5 ± 3.8 h. Prolonged second stage (20% vs. 2.4%, p < 0.05) was significantly associated with surgery, with trends toward more vacuum deliveries, no epidural, and greater hemoglobin decline. Postpartum hemorrhage and blood transfusion rates did not differ between groups.

Postpartum hematoma is rare but associated with vacuum delivery, episiotomy, second-degree laceration, and low BMI, while epidural analgesia is protective. Early recognition supports timely management.