New diagnostic criteria for clinical chorioamnionitis using only objective indicators: A retrospective study

BackgroundChorioamnionitis is a significant perinatal infection that adversely affects maternal and neonatal outcomes. Diagnostic criteria, including Lencki's criteria, are frequently used; however, they include subjective indicators, limiting their clinical utility. We aimed to establish diagnostic criteria using only objective indicators.MethodsThis retrospective cohort study involved patients who delivered at our hospital and underwent placental pathological examination from 2003 to 2022. Based on the Blanc classification, patients were classified into the CAM II/III (stage 2 or 3) and CAM I (stage 1) groups, followed by between-group comparisons of maternal and neonatal outcomes. Diagnostic indicators were selected through multivariate logistic regression analysis and used to develop a diagnostic model. Receiver operating characteristic curves were generated to compare the diagnostic performances of the new and previous criteria.ResultsAmong 862 included patients, 538 and 324 were classified as CAM II/III and CAM I, respectively. The CAM II/III group showed significantly higher rates of neonatal acidosis and maternal postpartum hospitalization ≥10 days. In the new model, scores were assigned as follows: body temperature ≥38.5°C (2 points), C-reactive protein ≥1.0 mg/dL (2 points), white blood cell count ≥12 × 10⁹/L (1 point), and nulliparity (1 point). A total score ≥4 points was considered the diagnostic threshold. The new criteria outperformed the existing criteria, with an area under the curve (AUC) value of 0.741 compared to 0.621 (p < 0.001).ConclusionsThe new criteria showed improved diagnostic accuracy for chorioamnionitis, which may facilitate early diagnosis and timely intervention for improved perinatal outcomes.