Patient: Can a child have B negative or B positive blood if mother is O negative and father is A positive.
Doctor: There are basically four primary common Blood types A, B, AB, O. If one parent has A and the has O, they can either prod uce a child with A or O blood types, but never a B or AB blood type. The same happens with the Rh types. With one parent having a Rh positive and the other being Rh negative, the child can either be Rh positive or RH negative.