Prognostic value of systemic inflammatory markers in predicting preterm delivery in patients undergoing cervical cerclage: A retrospective observational study

Background This study aimed to compare the clinical and perinatal outcomes of prophylactic and emergency cervical cerclage in patients diagnosed with cervical insufficiency and to identify factors affecting preterm labor. We also evaluated the prognostic value of inflammation indices in predicting early preterm labor (before 34 weeks' gestation). Methods This retrospective observational study included 122 singleton pregnancies that underwent cervical cerclage at a tertiary clinic between January 2023 and January 2025. Sixty patients underwent prophylactic cerclage, and 62 underwent emergency cerclage. Demographic, clinical, and perinatal outcomes were compared between the groups. Inflammatory markers such as the neutrophil-to-lymphocyte ratio (NLR), systemic immune inflammation index (SII), systemic inflammatory response index (SIRI), and delta neutrophil index (DNI) obtained from preoperative peripheral blood were calculated, and their role in predicting early preterm birth was analyzed. Results Preoperative cervical length, gestational age at delivery, and birth weight were significantly higher in the prophylactic cerclage group, and the rates of preterm premature rupture of membranes (PPROM), need for neonatal intensive care unit (NICU), and perinatal mortality were lower (p < 0.001). SII, SIRI, NLR, and DNI levels were significantly higher in patients delivering before 34 weeks of gestation. In ROC curve analysis, SII had the highest predictive accuracy (AUC = 0.853), followed by SIRI (AUC = 0.843), NLR (AUC = 0.738), and DNI (AUC = 0.726), respectively (all p < 0.001). Conclusions Prophylactic cerclage is associated with more favorable perinatal outcomes compared to emergency cerclage. SII demonstrated the highest discrimination in predicting early preterm birth (< 34 weeks), while DNI provided additional and significant prediction; however, the performance of NLR and SIRI was limited in this cohort. The use of these readily available biomarkers, in addition to clinical and ultrasound findings, may enhance risk stratification and support management decisions. Larger, multicenter, and prospective studies are needed to confirm these findings.