Predictors of Methotrexate Success and Fertility Outcomes in Tubal Ectopic Pregnancy: A Retrospective Cohort Study

Background and Objectives: Ectopic pregnancy (EP) is a potentially life-threatening condition and the leading cause of maternal mortality in the first trimester. Although both surgical and medical approaches are effective, selection criteria for Methotrexate (MTX) treatment remain inconsistent across international guidelines. Additionally, limited data on long-term reproductive outcomes are available. Materials and Methods: We conducted a single-center retrospective cohort study of 107 patients diagnosed with tubal EP and treated at the Obstetrics and Gynecology Unit of the University Hospital of Parma between 2019 and 2023. MTX (50 mg/m2) was offered to patients with β-hCG < 5000 mIU/mL, sac diameter < 40 mm, and no embryonic cardiac activity or hemoperitoneum; others underwent salpingectomy. Treatment outcomes, predictors of MTX success, and fertility outcomes were analyzed. Results: Medical treatment was offered to 36 patients (33.6%), with an overall success rate of 72%: in total, 20 resolved after a single dose and 6 after a second dose. Surgical conversion was necessary in 10 patients. The remaining 71 patients (66.4%) underwent primary salpingectomy. Initial β-hCG levels and gestational age did not significantly predict MTX failure (p 0.14 and 0.73, respectively), whereas gestational sac diameter was identified as a reliable predictor of treatment success (p = 0.01). In particular, a gestational sac maximum diameter of <2 cm emerged as a positive factor for MTX success (OR 1.13, 95% CI: 1.1–1.3, p = 0.04). Among the 50 patients with follow-up data, 68% achieved a term live birth, with no significant difference between the MTX (52.9%) and surgical (75.8%) groups (p 0.12). Most of the pregnancies (90%) occurred spontaneously, while only 10% required assisted reproductive technologies. Conclusions: MTX is a safe and effective treatment for tubal EP when patients are appropriately selected. Gestational sac diameter appears to be a reliable predictor of success. Both medical and surgical treatments yielded comparable reproductive outcomes, supporting individualized care models that prioritize fertility preservation.