ABO and Rhesus Compatibility in Blood Transfusion and Paternity

Understanding Blood Groups

Blood groups are classified based on the presence or absence of certain antigens on the surface of red blood cells. The two main systems are:

• ABO System: Determines blood type as A, B, AB, or O based on the presence of A and/or B antigens.
• Rhesus (Rh) System: Indicates the presence (+) or absence (-) of the Rh factor antigen, commonly referred to as Rh positive or Rh negative.

Blood Transfusion Compatibility

For a successful blood transfusion, the donor's blood type must be compatible with the recipient's. Incompatibility can cause serious reactions.

ABO Compatibility

• Type O: Universal donor; can donate to A, B, AB, and O.
• Type AB: Universal recipient; can receive from A, B, AB, and O.
• Type A: Can donate to A and AB; can receive from A and O.
• Type B: Can donate to B and AB; can receive from B and O.

Rhesus Compatibility

• Rh Positive (+): Can receive Rh+ and Rh- blood.
• Rh Negative (-): Should only receive Rh- blood to avoid complications.

Paternity and Blood Groups

Blood groups can help in determining paternity. By knowing the blood types of the mother, child, and alleged father, one can assess possible paternity.

Using Blood Groups in Paternity Testing

• If a child has blood type AB, one parent must have A and the other B.
• If a child is Rh+, at least one parent must be Rh+.