Predicting success of methotrexate treatment by pretreatment HCG level and 24-hour HCG increment.

OBJECTIVE

To evaluate β-human chorionic gonadotropin (β-HCG) level and its 24-hour increment as predictors of successful methotrexate treatment for ectopic pregnancy.

METHODS

Data were retrospectively reviewed from women with ectopic pregnancy who were treated by single-dose methotrexate (50 mg/m ) at a university hospital in Jerusalem, Israel, between January 1, 2000, and June 30, 2015. Serum β-HCG before treatment and its percentage increment in the 24 hours before treatment were compared between treatment success and failure groups.

RESULTS

Sixty-nine women were included in the study. Single-dose methotrexate treatment was successful for 44 (63.8%) women. Both mean β-HCG level and its 24-hour increment were lower for women with successful treatment than for those with failed treatment (respectively, 1224 IU\L vs 2362 IU\L, P=0.018; and 13.5% vs 29.6%, P=0.009). Receiver operator characteristic curve analysis yielded cutoff values of 1600 IU\L and 14% increment with a positive predictive value of 75% and 82%, respectively, for treatment success. β-HCG level and its 24-hour increment were independent predictors of treatment outcome by logistic regression (both P<0.01).

CONCLUSIONS

A β-HCG increment of less than 14% in the 24 hours before single-dose methotrexate and serum β-HCG of less than 1600 IU\L were found to be good predictors of treatment success.