Prognostic accuracy of a novel methotrexate protocol for the resolution of tubal ectopic pregnancies

Objective To evaluate if a decreasing human chorionic gonadotropin (hCG) between day (D) 1 and D7 is an equal or better predictor of tubal ectopic pregnancy (EP) resolution following methotrexate (MTX) treatment than the current standard of care. Study design This was a retrospective cohort prognostic accuracy study of women with a transvaginal ultrasound (TVS)-confirmed tubal EP (November 2006–December 2015). After single-dose MTX treatment, D4/7 hCG ratios were compared with that of D1/D7 in terms of sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) to predict EP resolution. Results Tubal EP was diagnosed in 301/7350 (4.1%) women who underwent TVS for early pregnancy-related complaints. The patients were managed accordingly: expectant, 84/301 (27.9%); MTX, 65/301 (21.6%); surgery, 152/301 (50.5%). A D1/D7 hCG ratio ≤0.85 predicted successful resolution of tubal EPs (P < 0.001) treated with MTX with sensitivity 0.84 [95% confidence interval (CI), 0.69–0.94]), specificity 0.71 [95%CI, 0.48–0.89], PPV 0.84 [95%CI, 0.69–0.94], NPV 0.84 [95%CI, 0.69–0.94], which is comparable to the prognostic performance of the D4/7 protocol. Conclusion In patients with tubal EP carefully selected for and treated with MTX, it may be reasonable to eliminate the D4 hCG in the follow-up algorithm.