Medical therapy can also be successful in treating certain groups of women who have an ectopic pregnancy. Medical treatment method involves the use of an anti-cancer drug called methotrexate (Rheumatrex, Trexall). This drug acts by killing the growing cells of the placenta, thereby inducing miscarriage of the ectopic pregnancy. Some patients may not respond to methotrexate, and will require surgical treatment. Methotrexate is gaining popularity because of its high success rate and low rate of side effects.

    There are certain factors, including the size of the mass associated with the ectopic pregnancy and the blood beta HCG concentrations that help doctors decide which women are candidates for medical rather than surgical treatment. The optimal candidates for methotrexate treatment are women with a beta-subunit (HCG) concentration less than or equal to 5000 mIU/mL. In a properly selected patient population, methotrexate therapy is about 90% effective in treating ectopic pregnancy. There is no evidence that the use of this drug causes any adverse effects in subsequent pregnancies. Additional tests (HCG) are usually ordered to confirm that methotrexate treatment is effective.