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
A prosthetic valve patient switches to heparin at what time during pregnancy: 
Select and explain. 
A. 28 wks, B. 32 wks, C. 36 wks, D. Post partum
C: 36 wks
Answer: C: 36 wks 
Explanation: Anticoagulants in Pregnancy
2 main anticoagulants are