Second-Trimester Inflammatory Markers in Predicting Fetal Growth Restriction: A Retrospective Analysis

Abstract

Problem: Fetal growth restriction (FGR) is a critical pregnancy complication linked to increased perinatal morbidity and mortality. Inflammation plays a key role in FGR's pathophysiology, and systemic inflammation markers may serve as predictors. This study evaluates the role of various inflammation indices; systemic immune-inflammation index (SII), systemic inflammatory response index (SIRI), pan-immune-inflammation value (PIV), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), lymphocyte-to-platelet ratio (LMR), monocyte-to-platelet ratio (MPR), aggregate systemic inflammation index (AISI), systemic coagulation inflammation index (SCII), and immature granulocyte percentage (IG%) in predicting FGR.

Methods of study: This retrospective study included 403 pregnant women treated at Ankara Etlik City Hospital between August 2022 and May 2024. The study population comprised 202 women with uncomplicated pregnancies (control group) and 201 women diagnosed with FGR per the Delphi Consensus Criteria. Second-trimester blood samples were used to calculate the inflammatory indices.

Results: SII and NLR levels were significantly higher in the FGR group compared to controls (p = 0.020, p = 0.028, respectively). However, no significant associations were found between these indices and adverse neonatal outcomes. Cut-off values for SII and NLR were 896 and 3.91, respectively, with moderate sensitivity and specificity.

Conclusions: SII and NLR, measured in the second trimester, may be useful in predicting FGR. Although these indices did not correlate with adverse neonatal outcomes, further prospective studies with larger populations are needed to validate their clinical utility.

Keywords: fetal growth restriction (FGR); inflammatory markers; neutrophil‐to‐lymphocyte ratio (NLR); systemic immune‐inflammation index (SII).