Efficacy of methotrexate treatment in extrauterine pregnancies defined by stable or increasing human chorionic gonadotropin concentrations

Abstract

Objective: To evaluate the efficacy of methotrexate treatment in selected cases of extrauterine pregnancy (EUP) defined by stable or increasing hCG concentration.

Design: Prospective cohort study.

Setting: Gynecology department of the Lis Maternity Hospital.

Patient(s): Fifty women with EUP diagnosed whenever an intrauterine gestational sac was not seen on transvaginal ultrasonography.

Intervention(s): Women received IM methotrexate at a dose of 50 mg/m(2) of body surface area. Failure of hCG levels to fall by >/=15% during any successive week resulted in repeated administration of methotrexate. Surgical intervention was performed for presumed tubal rupture.

Main outcome measure(s): Serial hCG measurement was performed weekly until hCG concentration reached 15 mIU/mL. Success was defined as the achievement of hCG concentration of 25 mIU/mL without surgical intervention.

Result(s): Forty-four women (88%) were successfully treated. The mean time from first methotrexate injection to success was 34 +/- 2.4 days. Women treated successfully and unsuccessfully differed significantly only with regard to serum hCG levels of 1,876 +/- 243 and 3,489 +/- 376 mIU/mL, respectively. When the initial hCG levels were lower or higher than 2,000 IU/L, the success rate was 97% and 74%, respectively (significant by Fisher's exact test).

Conclusion(s): When methotrexate treatment is administrated in a selected group of EUP defined by stable or increasing hCG, it may fail more frequently (26%) when initial hCG levels are >2,000 mIU/mL.