Day 4 and day 0 neutrophil-to-lymphocyte ratios as predictors of treatment failure with single-dose methotrexate for ectopic pregnancies

Objective: To evaluate changes in the neutrophil-to-lymphocyte ratio (NLR) between day 4 and day 0 in ectopic pregnancy (EP) patients treated with single-dose methotrexate (MTX) and investigate its predictive value for treatment outcome.Methods: A total of 406 EP patients receiving single-dose MTX therapy at Shanghai First Maternity and Infant Hospital from January 10, 2013 to September 30, 2019 were studied. A multivariate model was constructed to predict treatment outcome.Results: Among the 406 patients, 281 were treated successfully. Treatment success declined significantly when NLR decreased by less than 23% (74.8% vs 58.5%, P = 0.004). Multivariate regression analysis identified NLR reduction of less than 23% on day 4 (odds ratio [OR] 2.09, 95% confidence interval [CI] 1.27-3.44), a human chorionic gonadotropin (hCG) decrease of 15% or less (OR 3.17, 95% CI 1.62-6.34), and an hCG increase of more than 15% on day 4 (OR 5.47, 95% CI 3.05-10.22) as independent risk factors for single-dose MTX treatment failure. The final predictive model had a sensitivity of 0.768 and a specificity of 0.569, using a cut-off value of 3. The area under the receiver operating characteristic curve was 0.712. Patients with a predictive score of >= 3 were more likely to fail single-dose MTX therapy.Conclusion: The present study concluded that an NLR decrease of less than 23% on day 4, a plateau or increase in serum hCG on day 4, and an hCG value greater than 1000 mIU/mL on day 0 were predictors of single-dose MTX treatment failure in EP patients.