Determining a child's blood group is a study of a baby's blood sample, with the help of which a group is established according to the AB0 system. Also, this analysis helps to find out the Rh factor in a child. Why is this examination prescribed in childhood and how to take this test correctly?
Indications
The child will be assigned a blood group determination if:
- He will have a blood transfusion.
- The baby is planning to have an operation.
- The newborn is suspected of having hemolytic disease.
A blood sample is taken from the baby's vein for analysis. Most often, such an analysis is taken from a vein in the elbow region, but if the child is very small, blood can also be taken from other veins.
How is it determined?
The blood group depends on the presence of certain proteins in plasma and on erythrocytes. Such proteins on red blood cells are called antigens (they can be A and B) - agglutinogens. Antibodies to them, which are in the blood plasma, are called agglutinins (they are alpha and beta). Their different combination determines the allocation of 4 groups according to the AB0 system:
- 0 (zero) characterized by the absence of both types of antigens and the presence of both types of antibodies. This is the first group in our country.
- AND differs in the presence of agglutinogen A and beta antibodies. In our country, it is called the second.
- AT, in turn, has antibodies alpha and agglutinogen B. In domestic medicine, this is the third group.
- AB characterized by the absence of both types of antibodies and the presence of both types of agglutinogens. Domestic medicine calls it the fourth.
In the process of determining the group, antibodies are added to the test blood and the agglutination reaction (gluing of blood cells) is evaluated. For such an analysis, washed erythrocytes are used in newborns, and the reaction itself is carried out using monoclonal antibodies.
Rh factor
The Rh factor is a protein found in the blood of about 85% of people - the blood of such people is called Rh-positive. In the absence of such a protein, it is considered Rh negative. To determine Rhesus, antibodies are added to the blood sample and, after a few minutes, it is assessed whether the cells have agglutinated.
Is it possible to find out the blood group without analysis?
Without taking blood from a child, it is impossible to accurately determine the group and Rh. If there is a sample of the baby's blood and two ready-made serums (groups A and B), then it can be determined by gluing erythrocytes. You just need to mix the baby's blood with each serum in turn, and after 3 minutes you will see the adhesion of the cells.
Do I need to prepare for the test?
Special preparation for such an analysis is not required. It is often recommended to donate blood in the morning on an empty stomach, although this is not a prerequisite, but a recommendation, since food intake does not affect the level of antibodies and antigens.
