Development and Validation of a Nomogram Model for Predicting Chorioamnionitis in Patients with Term Premature Rupture of Membranes

Objective: This study aims to construct and validate a nomogram model based on clinical and laboratory indicators to predict the risk of histological chorioamnionitis in patients with premature rupture of membranes at term, and to evaluate its predictive efficacy and effectiveness. Methods: A total of 319 PROM patients admitted between May 2023 and December 2024 were randomly divided into a modeling group (n=221) and a validation group (n=98) at a 7:3 ratio. Based on placental and fetal membrane histopathology, the modeling group was classified into a non-HCA group (grade 0, n=138) and an HCA group (grades I-II, n=83). Results: /L, neutrophil percentage ≥75%, and PCT ≥0.05 mg/L as independent risk factors for HCA (P0.05). Decision curve analysis showed that within risk thresholds of 0.1-0.8 (modeling group) and 0.1-0.7 (validation group), the nomogram provided greater net clinical benefit than "treat-all" or "treat-none" strategies. Conclusion: Body temperature, delivery mode, WBC, neutrophil percentage, and PCT are significantly associated with HCA in PROM patients. The nomogram model shows good discrimination, calibration, and stability, and may assist in predicting HCA risk in clinical practice.