Abstract / Summary
Background & Objective: Chorioamnionitis is a significant complication of Preterm Premature Rupture of Membranes (PPROM) and a major contributor to perinatal morbidity and mortality. Early detection remains challenging, particularly in resource-limited settings. This study compared neutrophil-to-Lymphocyte Ratio (NLR) and C-Reactive Protein (CRP) in identifying histologically or microbiologically confirmed chorioamnionitis in patients with PPROM.Materials & Methods: This systematic review and diagnostic test accuracy meta-analysis adhered to PRISMA-DTA guidelines. PubMed, Scopus, Web of Science, and grey literature were searched through November 2025. Eligible studies evaluated maternal NLR and CRP in PPROM and provided sufficient data to reconstruct 2×2 contingency tables. Pooled estimates and Hierarchical Summary Receiver Operating Characteristic (HSROC) analysis were performed in STATA; SROC curves, Area Under the Curve (AUC) values, and heterogeneity were assessed using MetaDisc. The threshold effect was evaluated using Spearman correlation.Results: Eight studies were included. NLR demonstrated superior diagnostic performance compared to CRP, with a sensitivity of 0.75 (95% CI: 0.72-0.78), specificity of 0.71 (95% CI: 0.60-0.81), a Diagnostic Odds Ratio (DOR) of 7.39 (95% CI: 4.47-12.19; P=0.002), and an AUC of 0.81. CRP yielded a sensitivity of 0.68 (95% CI: 0.60-0.75), specificity of 0.68 (95% CI: 0.60-0.76), a DOR of 4.61 (95% CI: 2.80-7.59; P<0.001), and an AUC of 0.74. No significant threshold effect was observed for either marker.Conclusion: NLR showed higher diagnostic accuracy than CRP and may serve as a cost-effective, accessible screening tool for PPROM-related chorioamnionitis. Further research is warranted to establish optimal cut-off values and to evaluate the utility of NLR in integrated clinical prediction models.