The Predictive Value of Systemic Inflammatory Markers from Failed Single-Dose Methotrexate Therapy in Tubal Ectopic Pregnancy: A Retrospective Single-Center Study

Purpose: Assessing the systemic inflammatory markers as a prognostic factor for resistance to methotrexate in ectopic pregnancy. Methods: This retrospective cohort study included 412 cases of patients with tubal ectopic pregnancy who received single-dose methotrexate (MTX) therapy at the Obstetrics and Gynecology Hospital affiliated with Tongji University from January 2019 to January 2024. Participants were categorized into successful and unsuccessful cohorts according to single-dose methotrexate treatment. Systemic inflammatory parameters, particularly lymphocyte counts, NLR, and β-hCG, were collected for each case from blood tests. Regression analyses were employed to pinpoint independent risk factors linked to treatment failure. A nomogram was developed to represent these relationships. The model’s ability to distinguish outcomes was assessed by the area under the curve (AUC). Results: The research sample included 302 successful individuals and 110 unsuccessful ones. Compared with baseline, NLR decreased by less than 40.3% on Day 4 (95% CI 1.26– 3.12), while β-hCG levels rose on Day 4 (95% CI: 1.14– 2.80). HCG levels > 342.25 mIU/mL on day 0 (95% CI 1.74– 4.40) and lymphocyte counts > 2.165 × 10 9 /L on day 4 (95% CI 1.39– 3.42) were also predictive factors for treatment failure. ROC curve area was 0.705 (95% CI: 0.650– 0.760), with a Hosmer–Lemeshow test P-value above 0.05 (P = 0.607). Conclusion: Among systemic inflammatory markers, NLR and lymphocyte levels significantly correlate with treatment failure. Incorporating them with β-hCG into the model enhances risk predictive capability. Keywords: systemic inflammatory markers, neutrophil-to-lymphocyte ratio, clinical predictive modeling, ectopic pregnancy, methotrexate