Elevated Neutrophil-to-Lymphocyte Ratio in First Trimester of Pregnancy – Is a Predictor for Development of Pre-Eclampsia

Open Access

Abstract

Background: Pre-eclampsia is a major cause of maternal and perinatal morbidity and mortality, particularly in developing countries. Early identification of high-risk women remains challenging. The neutrophil-to-lymphocyte ratio (NLR), an inexpensive and readily available inflammatory marker derived from routine blood tests, has emerged as a potential predictor of adverse pregnancy outcomes. This study aimed to evaluate the role of first-trimester NLR in predicting the development of pre-eclampsia. Methods & Materials: This prospective observational study was conducted in the Department of Obstetrics and Gynaecology at Bangladesh Medical University (BMU), Dhaka, from January to December 2025. A total of 120 pregnant women in their first trimester (≤13 weeks) were enrolled consecutively. Socio-demographic and clinical data were recorded and complete blood counts were performed to calculate NLR. Participants were followed until delivery for the development of pre-eclampsia. Statistical analysis was performed using SPSS version 25, with p < 0.05 considered significant. Results: The mean age of participants was 26.8 ± 4.9 years. Elevated NLR (>3.5) was observed in 33.3% of women. Overall, 31 women (25.8%) developed pre-eclampsia. The incidence increased significantly with rising NLR values, from 11.1% in the <2.5 group to 45.0% in the >3.5 group (p = 0.002). Women with elevated NLR had nearly fourfold higher odds of developing pre-eclampsia (OR = 3.82; 95% CI: 1.61–9.05). Conclusion: First-trimester NLR is a simple, cost-effective and significant predictor of pre-eclampsia. Incorporating NLR into routine antenatal screening may facilitate early risk stratification and improve maternal outcomes.