Predictive Value of Inflammatory Indices for Preeclampsia and Adverse Perinatal Outcomes: A Retrospective Case-Control Study

Hüseyin Kayaalp,1,* Sertaç Ayçiçek2,* 1Department of Obstetrics and Gynecology, Perinatology Unit, Ankara Bilkent City Hospital, University of Health Sciences, Ankara, Turkey; 2Department of Obstetrics and Gynecology, Gazi Yaşargil Training and Research Hospital, University of Health Sciences, Diyarbakır, Turkey*These authors contributed equally to this workCorrespondence: Hüseyin Kayaalp, Department of Obstetrics and Gynecology, Perinatology Unit, Ankara Bilkent City Hospital, University of Health Sciences, Ankara, Turkey, Tel +90 507 611 00 66, Email huseyinkayaalp.2121@gmail.comPurpose: The aim of this study was to evaluate the predictive value of the systemic inflammatory index (SII), the systemic inflammatory response index (SIRI), and the aggregate systemic inflammatory index (AISI) in patients diagnosed with preeclampsia (PE) for PE and composite adverse perinatal outcomes (CAPO) in patients with PE.Patients and Methods: This single-center, retrospective case-control study included pregnant women aged 18– 45 years with PE and healthy controls. First- and third-trimester hematological parameters were recorded, and inflammatory indices were calculated. Neonatal intensive care unit (NICU) admission and CAPO were evaluated as clinical outcomes. Receiver operating characteristic (ROC) analysis assessed predictive performance, and multivariable logistic regression was used to adjust for confounding factors.Results: A total of 300 patients (150 with PE and 150 controls) were included. The PE group had significantly higher rates of NICU admission and CAPO (p < 0.05). Several first- and third-trimester inflammatory indices, including NLR, PNR, SII, SIRI, and AISI, were significantly higher in the PE group. ROC analysis demonstrated that multiple indices were associated with the prediction of PE, NICU admission, and CAPO. In multivariable analysis, third-trimester PLR remained an independent predictor of NICU admission, while third-trimester PLR and PMR were identified as independent predictors of CAPO (p < 0.05). For the prediction of PE, only first-trimester NLR and PNR remained independent predictors (p < 0.05).Conclusion: Inflammation-based indices derived from routine blood tests were associated with PE and adverse perinatal outcomes. Inflammation-based indices derived from routine blood tests were associated with PE and adverse perinatal outcomes. Certain indices demonstrated independent predictive value, particularly third-trimester PLR for NICU admission, third-trimester PLR and PMR for CAPO, and first-trimester NLR and PNR for PE. However, these indices should be interpreted in conjunction with clinical variables and considered as supportive markers rather than stand-alone predictors in clinical practice.