How do I get a new blood group card?

Answer

Best,

For a blood group determination, a lab needs a reliable sample. So it shouldn’t be too old. If your determination was made several years ago, the lab will likely request a new blood draw before issuing a new card. You can normally find out through your doctor which lab determined your blood group and your doctor can also perform a new blood sample if necessary.
Some labs require 2 separate blood samples to reliably determine your blood group. Errors can creep in, but if you have 2 separate determinations with the same result, there is a very good chance that the determination is correct.

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