Predictors of success in methotrexate treatment of women with unruptured tubal pregnancies

Objective The use of methotrexate (MTX) for the treatment of tubal ectopic pregnancy (EP) has become common practice, although the factors associated with a favorable outcome are not totally clear. The aim of this study was to investigate the predictors of successful MTX treatment. Methods One hundred and thirty-seven women with unruptured tubal EP in whom the hematosalpinx could be directly visualized by pelvic ultrasound were studied. Women who met the inclusion criteria were treated with MTX either: 50 mg/m2 intramuscularly (n = 70) or with 1 mg/kg injected directly into the hematosalpinx under sonographic guidance (n = 67). The associations between the outcome of the treatment and different factors studied (human chorionic gonadotropin (hCG) level, progesterone level, hematosalpinx diameter, hemoperitoneum volume and mode of MTX administration) were analyzed. Results The overall success rate, defined by a post-treatment normal hCG level (< 10 mIU/mL), was 79.6%. The initial hCG level and the route of administration of MTX appeared to be two independent factors that predicted success. Multivariate analysis demonstrated that the success rate was significantly better when MTX was administered locally: the odds ratio (OR) was 9.7 (95% CI, 3.1–30), and was significantly poorer when the hCG level was ≥ 1000 mIU/mL (P < 0.002): the OR was 0.10 (95% CI, 0.07–0.49). Conclusion Among selected women with tubal EPs, the route of administration of MTX and the initial level of serum hCG are the most important factors associated with the success of medical treatment. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.