The neutrophil-to-lymphocyte ratio as an inflammatory marker in preeclampsia: a retrospective cohort study from Saudi Arabia.

Preeclampsia (PE) is a major hypertensive disorder of pregnancy, with systemic inflammation being a key component of its pathogenesis. The neutrophil-to-lymphocyte ratio (NLR) has been investigated as an inflammatory biomarker for PE; however, its levels are rarely compared directly to both healthy pregnant and non-pregnant controls. This study aimed to evaluate the role of NLR in PE by comparing its levels across these three distinct groups. This retrospective study analyzed medical records from Abha Maternity and Children's Hospital (2022-2023), including 236 PE cases, 260 healthy pregnancies, and 100 non-pregnant controls. Biochemical and hematological parameters were assessed, as well as Receiver Operating Characteristic (ROC) analysis, which evaluated NLR's discriminatory power. Women with PE exhibited significantly elevated NLR compared to both the HP and NP groups (p < 0.001). ROC analysis showed that NLR could distinguish NP from PE with an AUC of 0.643 (p<0.0001) and NP from HP with an AUC of 0.623 (p=0.0003). An elevated NLR was associated with a 40.7% increased relative risk (RR=1.41, p<0.0001) and nearly threefold higher odds (OR=3.08, p<0.0001) of developing PE. It is concluded that NLR is significantly elevated in PE and demonstrates a significant association with increased risk of the disorder. These findings support its potential utility as an accessible, cost-effective inflammatory biomarker for aiding in the risk stratification of pregnant women. Further prospective studies are warranted to validate its clinical diagnostic value.