Single dose methotrexate for treatment of ectopic pregnancy: risk factors for treatment failure|
Objective: To identify risk factors for single dose methotrexate (MTX) failure among patients treated for ectopic pregnancies.
Design: Retrospective cohort.
Materials and methods: Seventy women diagnosed with an ectopic gestation treated with MTX. After a single dose, 66 (94.3%) patients experienced ectopic resolution, three (4.3%) patients needed a second dose of MTX, and one (1.4%) patient had a subsequent tubal rupture.
Main outcome measure(s): Predictive variables for failure of single dose MTX, including human chorionic gonadotropin (hCG) value, fetal sac size, patient age, parity and history of previous miscarriages.
Result(s): Ectopic pregnancies that failed to resolve following a single dose MTX were associated with increased maternal age, history of spontaneous abortions, larger sac sizes (>3.4 cm), and higher β-HCG levels (>2000 mIU/mL). Multiple regression analysis demonstrated that the size of the embryonic sac was the most important variable in failures of single dose methotrexate treatment.
Conclusion: Size of gestational sac and the pre-treatment level of HCG should be considered as independent risk factors for treatment failure of single dose methotrexate treatment.
Ectopic pregnancy, methotrexate, human chorionic gonadotropin, embryonic sac size, tubal rupture.