Inflammatory Indices and Preterm Delivery: A New Horizon in Obstetric Risk Assessment

<b>Objective:</b> Preterm delivery is a leading cause of neonatal morbidity and mortality globally, with inflammation playing a crucial role in its pathophysiology. This study aimed to evaluate the predictive value of systemic inflammatory response indices in identifying pregnant women at risk of preterm delivery. <b>Methods:</b> This retrospective study analyzed data from 1128 pregnant women admitted to a tertiary care hospital between 2020 and 2025. Patients were classified into two groups: preterm delivery (<i>n</i> = 528) and term delivery (<i>n</i> = 600). Demographic characteristics, obstetric history, neonatal outcomes, and inflammatory indices were compared. <b>Results:</b> The preterm delivery group showed a significantly higher systemic inflammatory response index (SIRI) (<i>p</i> < 0.001), systemic immune-inflammation index (SII) (<i>p</i> < 0.001), neutrophil/lymphocyte ratio (NLR) (<i>p</i> < 0.001), and monocyte/lymphocyte ratio (MLR) (<i>p</i> < 0.001) than the term delivery group, while platelet/lymphocyte ratio (PLR) levels were significantly lower (<i>p</i> = 0.002). Inflammatory indices were higher in early preterm delivery cases (<i>p</i> < 0.001) than in middle and late preterm cases. Multivariate logistic regression identified the SIRI (<i>p</i> = 0.015) and NLR (<i>p</i> < 0.001) as independent predictors of preterm delivery, while the PLR showed an inverse association (<i>p</i> = 0.002). Higher inflammatory indices correlated with lower 1st and 5th minute APGAR scores (<i>p</i> < 0.001) and increased neonatal intensive care unit (NICU) admission rates (<i>p</i> < 0.001). NICU stay was prolonged in neonates born to mothers with elevated SIRI and NLR levels (<i>p</i> < 0.001). <b>Conclusions:</b> Integrating these inflammatory indices into obstetric risk assessment may enhance early detection and intervention strategies, potentially improving maternal and neonatal prognosis.