Molecular and Genetic Medicine

Neutrophil to Lymphocyte Ratio and Red Blood Cell Distribution Width Levels in Preterm vs. Term Births

Abstract

Melissa CL, Aaron HG, Jonathan HBS, Angel GR and James A

Objective: Despite its broad etiology, preterm labor has been firmly linked to inflammatory/infectious processes. However, very few cases of preterm birth are preceded by acute signs and symptoms of clinical infection. Many studies have found neutrophil-to-lymphocyte ratio and red blood cell distribution width to be elevated in cases of subclinical infections. We performed a retrospective study to compare the levels of these two markers in preterm vs. term births.
Material and methods: Patient information was obtained retrospectively. Preterm and term birth patients were captured from our database during a three-year period. Neutrophil-to-lymphocyte ratio and red blood cell distribution width in the first trimester and on admission to labor and delivery was obtained. A sample size of 130 per group was required to find a 20% difference with 80% power (standard deviation=3.2). p-values less than 0.05 were considered significant.
Results: The preterm birth group contained 137 patients with an average gestational age of 32.4 ± 4.1 weeks and the term birth group included 145 patients with an average gestational age of 39.2 ± 1.1 weeks. The neutrophilto- lymphocyte ratio at the time of delivery was found to be higher in the preterm birth group (5.9 ± 5.1 vs. 4.6 ± 3.2, p=0.007).
Red blood cell distribution width at delivery did not differ between groups (13.6 ± 0.9, 13.9 ± 1.8, p=0.09). Subgroup analysis of preterm patients with preterm premature rupture of membranes (n=52) or gestational age <35 weeks (n=72) did not result in significant difference when compared to term patients.
Conclusion: Neutrophil-to-lymphocyte ratio was significantly elevated in preterm birth patients when compared to term patients. No statistically significant difference in red blood cell distribution width was found between groups.