Optimal Treatment for Women With a Persisting Pregnancy of Unknown Location

Inclusion Criteria: * Female with a persisting pregnancy of unknown location: * A pregnancy of unknown location is defined as a pregnancy in a woman with a positive pregnancy test but no definitive signs of pregnancy in the uterus or adnexa on ultrasound imaging. A definitive sign of gestation includes ultrasound visualization of a gestational sac with a yolk sac (with or without an embryo) in the uterus or in the adnexa. Ultrasound must be performed within 7 days prior to randomization. * Persistence of hCG is defined as at least 2 serial hCG values (over 2-14 days), showing \< 15% rise per day, or \< 50% fall between the first and last value. * Patient is hemodynamically stable, hemoglobin \>10 mg/dL * Greater than or 18 years of age Exclusion Criteria: * Hemodynamically unstable in need of acute treatment * Most recent hCG \> 5000 mIU/mL * Patient obtaining care in relation to a recently completed pregnancy (delivery, spontaneous or elective abortion) * Diagnosis of gestational trophoblastic disease * Subject unwilling or unable to comply with study procedures * Known hypersensitivity to MTX * Presence of clinical contraindications for treatment with MTX * Prior medical or surgical management of this gestation * Subject unwilling to accept a blood transfusion