Blood group Rhesus Antigen

Patient: Ok my son is 9 years old, what i do know is that his mother is rh negative, i am o positive what are the chances that the two parents would make a child with a positive blood type

Doctor: Your son may inherit the Rhesus antigen from either parent. If he inherits the Rhesus antigen from you (O+) he will be R hesus positive. If he inherits Rhesus status from his mother (-ve), he will not inherit the Rhesus antigen and will be Rhesus negative. Basically there is a 1 in 2 chance that he is Rhesus positive. Blood groups are inherited from both parents; this does not mean that your son’s blood group is identical to either parent or siblings.