First trimester neutrophil to lymphocyte ratio (NLR) and pregnancy outcome

In early pregnancy, miscarriage is the most common complication. The early identification of women at high risk for miscarriage could improve pregnancy outcomes. We investigated whether the first trimester neutrophil to lymphocyte ratio (NLR) could be used as a prognostic marker for miscarriage, in pregnancies after spontaneous conception. We retrospectively identified 129 pregnant women who had a first trimester full blood count available and known pregnancy outcome. First trimester NLR was calculated for each woman and mean NLR values were compared between women with live births (group 1) with those with miscarriage (group 2). Mean NLR values were not significantly different between the two groups (2.5 ± 1.0 vs. 2.9 ± 1.5, p = .167) and were not associated with pregnancy outcomes. However, NLR values >5.8 were exclusively observed in the miscarriage group (p = .028).IMPACT STATEMENTWhat is already known on this subject? As a marker of inflammation, NLR has been found to be elevated in various diseases and complications that affect pregnancy outcome. Pregnancy complications, such as preeclampsia and gestational diabetes have been associated with an increased NLR, but little is known on their direct causal relationship. So far, there has been no evaluation of maternal NLR in regards to miscarriage in otherwise healthy women.What do the results of the study add? We found that NLR does not differ significantly between pregnant women with live birth and those whose pregnancy ended in miscarriage . However, NLR values >5.8 were solely found in the miscarriage group- an observation that was statistically significant.What are the implications of these findings for clinical practice and/or further research? The above finding supports high NLR values as a potential marker for the identification of the subset of miscarriages in otherwise healthy pregnant women. This may allow personalised approaches to prevent pregnancy loss.