The importance of blood-count-derived inflammatory markers in predicting methotrexate success in patients with tubal ectopic pregnancy.

OBJECTIVE

To investigate the systemic immune-inflammation index (SII) and neutrophil-to-lymphocyte ratio (NLR) in predicting a successful methotrexate response in tubal ectopic pregnancy (TEP).

METHODS

Women treated for TEP at a tertiary hospital between 2017 and 2021 were retrospectively reviewed. A total of 502 (100%) eligible patients who received methotrexate were included and divided into two groups based on whether or not they were successfully treated with methotrexate alone. Inflammatory parameters derived from the patients' hemograms at hospital admission were compared.

RESULTS

In total, 434 (86.4%) patients were successfully treated with methotrexate alone (Group 1), while 68 (13.6%) patients underwent surgery after methotrexate failure (Group 2). Median neutrophil count, NLR, platelet-to-lymphocyte ratio, monocyte-to-lymphocyte ratio, SII, largest ectopic mass diameter, and β-human chorionic gonadotropin (β-hCG) were significantly lower, whereas median lymphocyte and platelet counts were significantly higher in Group 1. According to the receiver operating characteristic analysis performed for the discriminatory power of NLR, β-hCG, and SII for methotrexate response, the area under the curve values were 0.742, 0.730, and 0.699, respectively.

CONCLUSION

Low NLR and SII are associated with methotrexate success and could be used to refine decision making regarding β-hCG for predicting successful response to methotrexate in patients with TEP.