Urgent referral Hemodynamic instability Peritoneal signs Ultrasonography shows ectopic pregnancy with fetal cardiac activity Ultrasonography shows substantial fluid in the cul-de-sac and/or beyond

Other indications for referral Barriers to close follow-up or refusal to accept blood transfusion High initial β-hCG levels (> 5,000 to 10,000 mIU per mL [5,000 to 10,000 IU per L]) or ectopic pregnancy > 4 cm Insufficient decline in β-hCG levels after administration of methotrexate Medical conditions that preclude medical management with methotrexate (e.g., active peptic ulcer disease, active pulmonary disease, anemia, breastfeeding, clinically important hepatic or renal disease, immunodeficiency, leukopenia, thrombocytopenia)