Single-dose methotrexate injection for treatment of ectopic pregnancy in women with relatively low levels of human chorionic gonadotropin

Objective To evaluate potential risk factors at admission for failed single-dose methotrexate injection in women with ectopic pregnancy. Methods File review of a tertiary medical center in Israel yielded 102 consecutive patients with ectopic pregnancy initially treated with single-dose methotrexate. Overall successful treatment was defined as normalization of human chorionic gonadotropin (hCG) levels after the first or second injection. Results The mean pretreatment hCG level for the whole cohort was 2350 ± 2955 mIU/mL (median, 1187 mIU/mL; 90th percentile, 5000 mIU/mL). Resolution of ectopic pregnancy was achieved after a single injection in 76/102 (74.5%) women and after a second dose in 16/21 (76.2%) women. The remaining 10 (9.8%) patients were treated surgically after the first (5/76) or the second (5/26) dose. The overall success rate for methotrexate treatment was 90.2%. On multivariate stepwise logistic analysis, fetal cardiac activity was an independent predictor of a failed first methotrexate injection, and presence of a yolk sac and mass size were independent predictors of overall methotrexate failure and need for secondary surgery. Conclusion In patients with ectopic pregnancy and relatively low levels of serum hCG, the most important predictors of overall failure of methotrexate injection were the presence of a yolk sac and mass size.