Determining treatment success in tubal ectopic pregnancies – the predictive value of the delta neutrophil index in single-dose methotrexate therapy

Introduction and aim. This study assessed the significance of the Delta neutrophil index (DNI) in predicting the effectiveness of single-dose methotrexate (MTX) treatment for tubal ectopic pregnancy. Material and methods. In this retrospective study, 214 women diagnosed with tubal ectopic pregnancies and treated with MTX between 2019 and 2022 were included. Group 1 comprised 88 MTX responders, while group 2 consisted of 86 non-responders necessitating surgery. HCG and DNI levels were monitored on day 1, 4, and 7 of MTX treatment and compared between the groups. Results. Group 1 exhibited significantly lower HCG and DNI levels compared to group 2 on days 1, 4, and 7 (p<0.001). Both HCG and DNI levels on days 1 and 4 of MTX treatment were significant predictors of treatment failure, with the highest AUC observed for DNI was on day 4. In multivariate logistic regression analysis, elevated DNI levels on day 1 of MTX treatment were associated with a 5.8-fold increased risk, and DNI levels on day 4 were associated with a 4.44-fold increased risk of MTX treatment failure. Conclusion. DNI emerges as a valuable marker for predicting the success of single-dose methotrexate treatment in tubal ectopic pregnancies, demonstrating superior predictive power compared to HCG.