What are the different blood types

How many blood types are there?

Blood group systems are very complex. A blood group is a set of antigens, substances capable of inducing an immune response by interacting with other substances, and it differs from one individual to another within the same species.

There are currently 40 antigenic systems that allow blood cells to be identified and define blood compatibility and incompatibility between individuals. The best known and used are the ABO and Rhesus systems.

Blood type depends on each person’s genetic makeup, as well as the mixing of populations and geographical areas around the world. Some blood types are common, others less common, and others rare. Each individual has their blood type and this group remains the same throughout life.

The main blood groups

The ABO system is the oldest known blood group system. It is inseparable from the Rhesus system. Determining the ABO/Rhesus blood group is useful in determining blood compatibility between individuals, particularly during blood transfusions or during pregnancy.

There are 4 main ABO groups, determined by the antigens present in red blood cells (blood cells that carry oxygen in the blood): A, B, O, and AB.

Blood type is also classified according to the associated Rh group: positive (+) or negative (-) depending on the presence or absence of the Rh antigen on the surface of the red blood cells.

So there are 8 different main blood groups in total, including 3 common ones and 5 rarer ones:

Most common blood groups in France:

  • A positive: 38% of the population
  • O positive: 36% of the population
  • B positive: 8% of the population.

Rarer blood types:

  • A negative: 7% of the population, this is the universal group for platelet donation;
  • O negative: 6% of the population, this is the “universal donor” group;
  • AB positive : 3% of the population;
  • B negative: 1% of the population;
  • AB negative: 1% of the population.

Are there universal blood types?

The O negative group is the so-called “universal donor” group, which means that it can be used in blood transfusions for everyone, regardless of the recipient’s blood type. It is therefore used especially in emergencies.

Conversely, the AB-positive group can receive blood from all blood groups; this is the group called the “universal recipient”

How to know your blood type?

To determine an individual’s blood group, two blood samples must be taken. These samples are usually taken in France in these situations:

  • at birth: the blood group is determined at the birth of the child and recorded in their health record;
  • during pregnancy: if you are pregnant and do not know your blood type, the doctor in charge of monitoring you may prescribe a blood type and rhesus test during the first trimester;
  • during blood donation: the blood group is communicated following a blood donation because the compatibility test is mandatory to guarantee the safety of the recipient during the transfusion.

It is also possible to perform a blood group determination outside of these situations. In all cases, the samples must be prescribed by a doctor and carried out in an analysis laboratory or directly at the hospital.

Rare blood types

Every individual is different, and their blood is no exception: in France, a blood group is considered rare when:

  • less than 4 people in 1000 have it in the population;
  • There is no other compatible blood group to transfuse these patients.  

This would affect around 700,000 people in France. Around 250 rare blood groups have been identified in our country. In metropolitan France, for example, the blood groups that are particularly likely to be rare or uncommon are those of people from Africa, the Caribbean (Martinique, Guadeloupe, Guyana) or the Indian Ocean (Réunion, Mayotte, Comoros, etc.).

It is therefore essential to have many blood donors to save as many people as possible who may need a blood transfusion one day in their lives. Blood group diversity is as important as the donation itself to achieve a diversity of blood donors representing the diversity of the transfused population.

Livi doctors can prescribe a blood group determination, or give you information, particularly in the event of pregnancy. It should be noted that blood group determination is only reimbursed in France by Health Insurance for pregnant women and patients in a proven transfusion context.


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