This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
Which of the following would be most likely causing methotrexate therapy failure in ectopic pregnancy treatment. 
Select and explain. 
A. Multiparous woman, B. Ectopic size > 2.5 cm, C. Previous history of ectopic pregnancy, D. Serum β hcG level of 9000 mIU / mL.
D: Serum β hcG level of 9000 mIU / mL.
Answer: D: Serum β hcG level of 9000 mIU / mL. 
Explanation: With methotrexate therapy, serum β-hcG levels should decline. If β-hcG rises then it is failure of medical management.