The optimal cutoff serum level of human chorionic gonadotropin for efficacy of methotrexate treatment in women with extrauterine pregnancy.

OBJECTIVE

To evaluate the efficacy of methotrexate treatment for extrauterine pregnancy and define criteria for prediction of success.

METHODS

Of 829 patients with an ectopic pregnancy admitted to E. Wolfson Medical Center, Holon, Israel, from January 1997 through December 2009, 238 had asymptomatic tubal pregnancies and increasing serum β-human chorionic gonadotropin (βhCG) levels. These patients were treated with a single intramuscular injection of 50mg of methotrexate (MTX) per square meter of body surface. Success was defined as undetectable βhCG levels without the need for a surgical intervention.

RESULTS

The groups of patients successfully treated (n=167 [70%]) and unsuccessfully treated (n=71 [30%]) were compared. They were similar regarding age and gravidity. The initial serum βhCG level was significantly higher in the latter group than in the former (3798 mIU/mL vs. 1601 mIU/mL, P<0.01). The success rate was 88% when initial βhCG levels were less than 1000 mIU/mL, 71% when they were between 1000 and 2000 mIU/mL, and only 59% when they were between 2000 and 3000 mIU/mL.

CONCLUSION

Methotrexate treatment is a safe and effective alternative to surgery. However, patients with initial βhCG levels higher than 2000 mIU/mL should only be offered the surgical approach.