The blood type of a child is determined by both the father’s and mother’s blood types. There is no gender difference in the influence of the father or mother on the blood type of the baby, referred to as one person and the other. If the father, called one person, is type O and the other person is also type O, the baby’s blood type can only be O. If one person is O and the other is A, the baby’s blood type can only be O or A. If one person is O and the other is B, the baby’s blood type can only be O or B. If one person is O and the other is B, the baby’s blood type can only be O or B. If one person is O and the other is AB, the baby’s blood type can only be A or B. If both are type A, the baby’s blood type can only be O or A. If one person is A and the other is B, the baby’s blood type may be O, A, B or AB. If one person is A and the other is AB, the baby’s blood type may be A, B or AB. If both are type B, the baby’s blood type may be O or B. If one person is type B and the other is type AB, the baby’s blood type may be B, A or AB. If both people have blood type AB, the baby’s blood type may be A, B or AB.