Predictors of Success of Repeated Injections of Single-dose Methotrexate Regimen for Tubal Ectopic Pregnancy

The purpose of this study is to evaluate predictors of success of repeated injections of methotrexate in the single-dose regimen for the treatment of tubal ectopic pregnancy. All patients who had ectopic tubal pregnancy and were treated with a single dose regimen were retrospectively identified. 126 patients were treated with methotrexate. Among them, 39 patients were adequate for this study. 33 were treated with the 2nd dose and 27 were successfully cured. Additionally, 6 who were injected with the 3rd dose were all cured as well. Therefore, in our study, the success rate for the repeated injections of methotrexate was found to be 84.6% (33/39). The mean initial β-hCG level was significantly lower in patients who were successfully treated than in patients who failed (3915.3±3281.3 vs. 8379.7±2604.4 IU/mL, p<0.05). The success rate is 96% when the β-hCG level is less than 6,000 IU/mL and is 58% when β-hCG is greater than 6,000 IU/mL (OR=18.57, 95% CI 1.86-185.89). The initial β-hCG level is the only factor that has significant meaning as predictor of success of repeated injections of methotrexate in the single-dose regimen. Repeated injections of methotrexate may be particularly effective when the initial β-hCG level is below 6,000 IU/mL.