Would you believe my whole family is O-, I am, DH is and all 4 boys are I was always lead to believe that O- is the universal blood, it can be given to anybody if there blood type is unknown, or their type of blood is unavailable.

Must say I hadn't really thought about having an alert, I will be making sure all boys know what there bloody type is, DH didn't find out until about 2 years ago.