Abstract
BACKGROUND AND OBJECTIVE: Histologic chorioamnionitis (HCA) complicates preterm birth and adversely affects neonatal and maternal outcomes; however, early recognition remains challenging. Here, we aimed to identify risk factors for HCA and assess its impact on pregnancy outcomes in preterm deliveries with prenatal fever. DESIGN: Retrospective cohort analysis. SETTING: Tertiary obstetrics and Gynecology Hospital in Shanghai, China. PARTICIPANTS: A total of 220 women who delivered preterm (gestational age <37 weeks) with prenatal fever between January 2018 and December 2020 were ultimately included in the study. This included an HCA group (101 cases) and control group (119 cases). MAIN OUTCOME MEASURES: HCA diagnosis by placental pathology; neonatal outcomes. RESULTS: The incidence of congenital infection (27.66 vs 15.38%, P=0.029) and neonatal sepsis (8.89 vs 0.90%, P=0.017) was significantly greater in the HCA group than in the control group. Fever interval and PROM between 24 to 48 h (aOR=3.603, 95% CI 1.027~12.644) and >48 h (aOR=6.201, 95% CI 1.729~22.238) were associated with HCA. A maternal WBC count ≥11×10(9)/L demonstrated a sensitivity of 80%, a specificity of 46%, a positive predictive value of 56.3%, and a negative predictive value of 73.3% for HCA prediction. A maternal white blood cell count ≥11×10(9)/L demonstrated optimal discriminatory power for HCA (AUC=0.667, 95% CI 0.569~0.738). CONCLUSION: HCA significantly increases the risks of neonatal sepsis and congenital infection in preterm infants. A prolonged PPROM-fever interval (> 24 h) and a maternal WBC ≥11×10(9)/L are key predictive factors for the need for active obstetric intervention. This study provides evidence-based cutoff values for clinical decision-making in preterm pregnancies with fever, potentially improving maternal and neonatal outcomes through timely intervention.