At a Glance
Why Get Tested?
To determine your ABO blood group and Rh type
When to Get Tested?
When you need a transfusion of blood or blood components; when you donate blood at a collection facility or donate an organ, tissue, or bone marrow for transplantation; before or during a woman's pregnancy to determine the risk of Rh incompatibility with the fetus
A blood sample drawn from a vein in your arm or, for infants, from a heelstick
Test Preparation Needed?