Prophylactic methotrexate after linear salpingostomy: a decision analysis

Objective: To compare two strategies for managing women after linear salpingostomy for treatment of tubal pregnancy: observation and prophylactic methotrexate.

Design: Decision analysis.

Setting: Outpatient tertiary-care center.

Patient(s): One thousand hypothetical women treated with a linear salpingostomy for ectopic pregnancy.

Intervention(s): Observation after salpingostomy and treatment of persistent ectopic pregnancy with a single dose of methotrexate (current standard of care) versus treatment with prophylactic methotrexate at the time of salpingostomy.

Main Outcome Measure(s): Number of ruptured ectopic pregnancies, surgical procedures, complications, and cost for each group (observation vs. prophylaxis).

Result(s): Prophylactic methotrexate results in fewer cases of tubal rupture (0.4% vs. 3.7%) and fewer procedures (1.9% vs. 4.7%) at a lower cost ($67.55 less/patient) compared with observation alone. Methotrexate-associated complications occur more frequently with prophylaxis (5.5% vs. 0.8%). Certain conditions change which strategy is preferable. Observation is the best strategy when the persistent ectopic pregnancy rate is <9%, the success of prophylaxis is <95%, the complication rate associated with methotrexate is >18%, or the rupture rate of persistent ectopic pregnancies is <7.3%.

Conclusion(s): Prophylactic methotrexate at the time of linear salpingostomy for the treatment of ectopic pregnancy is preferable to observation as long as certain conditions exist.