The American College of Obstetricians and Gynecologists (ACOG) has issued a practice bulletin on the medical management of tubal pregnancy. ACOG Practice Bulletin No. 3 was published in the December 1998 issue of Obstetrics and Gynecology. The seven-page practice bulletin was developed by the ACOG Committee on Practice Bulletins with the assistance of Steven J. Ory, M.D. The purpose of the report is to present evidence about methotrexate as an alternative treatment to surgery for selected patients with ectopic pregnancies. Methotrexate is a folinic acid antagonist that inhibits dihydrofolic acid reductase. It has been used in the treatment of patients with small unruptured tubal pregnancies.

The ACOG document includes discussions on the incidence, etiology and diagnosis of ectopic pregnancy, the effects of therapy, and success rates of using methotrexate. Clinical considerations and recommendations that are covered in the report include how to select candidates for medical management; how methotrexate is used; potential problems associated with medical management; counseling about medical therapy; cost-effectiveness of medical management; and the role of expectant management.

According to ACOG, the success rates reported from various studies on the resolution of ectopic pregnancy without surgical intervention range from 67 to 100 percent (median: 84 percent for the single-dose regimen). Some women require more than one dose. ACOG notes that the different success rates in the studies may be caused by selection criteria and management differences.

The report provided the following absolute indications for a patient to receive methotrexate: hemodynamic stability with no active bleeding or signs of hemoperitoneum, a nonlaparoscopic diagnosis, desire to get pregnant again, contraindication for general anesthesia, willingness to comply with follow-up care and no contraindications to the drug itself.

The side effects of methotrexate are signficant, and ACOG recommends counseling patients about the potential problems of taking the drug. Counseling should include information about drug-related side effects, as well as treatment-related complications and treatment failure. Side effects include nausea, vomiting, stomatitis, diarrhea, gastric distress, dizziness, pneumonitis and, although rare, severe neutropenia and reversible alopecia. Additional treatment is necessary in the case of treatment failure and if rupture occurs, rapid surgical intervention is necessary.

The following three recommendations taken from the ACOG summary of the report are based on limited scientific evidence:

• Intramuscular methotrexate is appropriate for selected patients with small, unruptured tubal pregnancies.

• Successful treatment may require more then one dose of methotrexate.

• Failure of beta human chorionic gonadotropic (β-hCF) levels to decrease by at least 15 percent from day 4 to day 7 after methotrexate administration indicates the need for an additional dose of methotrexate or surgery.

ACOG bases the following recommendation primarily on consensus and expert opinion:

• There may be a role for expectant management of hemodynamically stable patients with presumptive ectopic pregnancy in whom β-hCF levels are low and declining.