In medicine, blood types are generally divided into six types: AA, OA, BB, OB, AB, and O. Type AA and OA are collectively referred to as type A, and type BB and OB are also collectively referred to as type B.
The ABO blood group system is the most important blood group system in human blood transfusion. The ABO blood group system was discovered by Karl Landsteiner, an Austrian-American immunologist and pathologist, in 1901. He won the Nobel Prize in Physiology or Medicine in 1930 for this discovery.
The blood type of a child is a new blood type formed by mixing a part of the father's blood type (A, B, or O) with a part of the mother's blood type (A, B, or O). This new blood type is the child's blood type, so the child's blood type is related to the parent's blood type.
Blood types are inherited genetically from our parents. Each parent contributes one of two ABO genes to their child. The A and B genes are dominant, and the O gene is recessive. This means:
| Parental blood type | Child's possible blood type | Child's impossible blood type |
|---|---|---|
| A × A | A, O | B, AB |
| A × B | A, B, AB, O | - |
| A × AB | A, B, AB | O |
| A × O | A, O | B, AB |
| B × B | B, O | A, AB |
| B × AB | A, B, AB | O |
| B × O | B, O | A, AB |
| AB × AB | A, B, AB | O |
| AB × O | A, B | AB, O |
| O × O | O | A, B, AB |
Understanding blood types is crucial for several reasons:
In addition to the ABO system, there's another important blood group system called the Rh system. People are either Rh positive (+) or Rh negative (-). This factor is particularly important during pregnancy, as Rh incompatibility between mother and child can lead to complications.
Understanding blood types helps ensure safe medical procedures and can even save lives.