Association of Systemic Inflammation Markers with Early Pregnancy Loss in the First Trimester: A Retrospective Study

Objective This study aimed to investigate whether hematologic inflammatory markers derived from routine complete blood count (CBC) are associated with early pregnancy loss during the first trimester. Methods In this retrospective case-control study, 217 women diagnosed with missed abortion and 192 healthy pregnant women who gave birth at term were included. Data were obtained from patient records at the Obstetrics and Gynecology Clinic of Sirnak State Hospital between January 2022 and April 2025. Inflammatory indices—including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), systemic inflammation response index (SIRI), and aggregate index of systemic inflammation (AISI)—were calculated from CBC parameters and compared between the groups. Results Gravida, parity, and body mass index (BMI) were significantly higher in the missed abortion group (p < 0.001), while maternal age and gestational week showed no significant difference. Hematologic parameters, including hemoglobin, white blood cell count, neutrophils, lymphocytes, monocytes, and platelets, were significantly elevated in the missed abortion group (p < 0.05). Inflammatory markers such as NLR, SII, SIRI, and AISI were significantly higher in this group, while PLR showed no statistical difference (p = 0.128). Among these, SII (AUC = 0.74), SIRI (AUC = 0.73), and AISI (AUC = 0.67) demonstrated the strongest discriminative performance in ROC analysis. Conclusion First-trimester inflammatory indices, particularly SII, SIRI, and AISI, may serve as accessible, low-cost biomarkers for identifying pregnancies at risk of early loss. Further prospective studies are needed to validate their clinical utility.