neutrophil-to-lymphocyte ratio as a predictor of chorioamnionitis in preterm premature rupture of membrane: a systematic review and meta-analysis

Background & objective: chorioamnionitis prevails 30%-80% in preterm premature rupture of membranes (pprom) and is associated with adverse maternal and neonatal outcomes. this study was conducted with aim to evaluate the diagnostic accuracy of neutrophil-to-lymphocyte ratio (nlr) as an inflammatory marker in predicting chorioamnionitis in pprom cases.materials & methods: this systematic review and meta-analysis was conducted following prisma guidelines. databases (pubmed, scopus, cochrane library) were searched for studies published up to november 2024. included studies assessed maternal nlr and histologically or microbiologically confirmed pprom-related chorioamnionitis. quality assessment was conducted using the quality assessment of diagnostic accuracy studies-2 (quadas-2), and the statistical analyses were performed using metadisc and stata software.results: of ten studies eligible for qualitative synthesis, eight were included in the meta-analysis. in pooled analysis, nlr demonstrated good diagnostic accuracy for predicting chorioamnionitis in pprom with pooled sensitivity of 75% (95% ci 72-78%), specificity of 69% (95% ci 66-73%), diagnostic odds ratio was 7.12 (95% ci, 4.4-11.41; p=0.001), and the area under the curve (auc) of 0.809. meanwhile, for subclinical chorioamnionitis (five studies), nlr showed a sensitivity of 77% (95% ci 72-81%), specificity of 61% (95%ci 56-66%), dor of 5.11 (95% ci 3.59-7.29; p=0.33) and auc of 0.782.conclusion: nlr demonstrates moderate for predicting chorioamnionitis in pprom. nlr may serve as a simple and accessible screening tool in resources-limited settings to enable early detection, timely referral or intervention, and ultimately improve both maternal and neonatal outcomes. further research should explore optimal cut-off values and combinations with other biomarkers to enhance predictive performance.