Utility of Neutrophil to Lymphocyte Ratio in Hypertensive Disorder of Pregnancy: A Case-control Study

Introduction: Hypertensive Disorders of Pregnancy (HDP), encompasses gestational hypertension, Preeclampsia and eclampsia, remain leading causes of maternal and perinatal morbidity and mortality globally. Among several biomarkers under investigation, the Neutrophil-To-Lymphocyte Ratio (NLR) has emerged as a potential indicator of systemic inflammation, with relevance in predicting disease severity and outcomes in HDP. Aim: To evaluate the utility of NLR as a biomarker in HDP. Materials and Methods: This prospective case-control study was conducted in the Department of Obstetrics and Gynaecology, Government Medical College and Rajindra Hospital, Patiala, Punjab, India, from January 2021 to December 2021 (12 months). The study population included 100 pregnant women diagnosed with HDP (gestational hypertension, Preeclampsia, eclampsia, chronic hypertension and preeclampsia superimposed on chronic hypertension) and 100 normotensive pregnant women as controls. Complete Blood Count (CBC) were analysed and NLR was calculated. Data were compiled in Microsoft Excel and analysed using Statistical Package for the Social Sciences (SPSS) version 26.0 (IBM Corp., USA). Continuous variables were expressed as mean±Standard Deviation (SD), while categorical variables were presented as frequencies and percentages. Comparison between two groups was performed using independent sample t-test for normally distributed variables or the Mann-Whitney U test for non parametric data. Categorical variables were compared using the Chi-square test or Fisher’s-exact test, as appropriate. The association between NLR and the severity of HDP was assessed using the Chi-square test. A p-value of <0.05 was considered statistically significant. Results: The mean NLR was significantly higher in hypertensive pregnant women (mean±SD: 3.69±0.95) compared to normotensive controls (2.81±0.15). Among cases, patients with preeclampsia and eclampsia had higher NLR values (4.23±0.62 and 5.00±0.00, respectively) than those with gestational hypertension (3.00±0.25). A positive association was observed between NLR levels and disease severity (p<0.001), with the highest values seen in severe preeclampsia and eclampsia (4.23±0.62 and 5.00±0.00, respectively). Conclusion: The NLR is a simple, inexpensive and readily available biomarker that may serve as an early predictive indicator for hypertensive disorders of pregnancy. Its integration into routine antenatal screening could enhance risk stratification and improve clinical management.