Q: Good evening doctor, thanks a lot for your answer its really helping us. Please Doc, I will want to know if it is possible for a mother and father to be A+ while the child is o+

A: Everyone’s blood contains antigens and antibodies which form the blood’s defense against foreign bodies. The antigen and antibody present in your blood determines your blood group.

Your blood is made up of red blood cells (which carry oxygen round the body), white blood cells (which help fight infections) and platelets (which help clotting) suspended in plasma (a liquid).

Your blood group depends on genes inherited from your parents.

People with blood group A have A antigen on their red blood cells and Anti-B antibodies in their plasma. Thus, giving this person blood from someone with blood group B will lead to the antibodies (anti-B) attacking that person’s B antigen.

A is dominant to O and so people with A blood group can either have the genotype ‘AA’ or ‘AO’. If two parents have the ‘AO’ blood type genotype, they have a 25% chance of having a child with O+ blood group, 75% of having children with blood group A (25% with AA blood type genotype and 50% with AO blood type genotype).

So the simple answer is yes, it is possible to have an O+ child even when both parents are A+

All the best!