Analyzes on the establishment of paternity

What is the establishment of paternity?

The establishment of paternity is a medical study, the results of which allow us to conclude whether this man is the biological father of the child.

How is paternity determined?

First of all, they try to exclude the possibility that this man is the biological father of the child. For this, an analysis is made of the blood of the child, his mother and the alleged father.
Analysis of signs of blood groups

The blood group (A, B, AB or O) and the Rhesus factor are inherited according to a strict pattern. Therefore, in some cases, biological paternity can be excluded already based on the results of a blood test. In addition, not only the blood group and the Rh factor are evaluated, but also other properties characteristic of a particular blood group.

Finally, the study of erythrocytes, enzymes and many proteins circulating in the blood plasma also occurs with observance of certain regularities. When establishing paternity, individual differences in DNA are also examined. More and more important are the properties of leukocytes, which are inherited. The muzzle was that on the surface of leukocytes it was possible to establish the presence of certain antigens important for the human immune system.
Comparing the antigens of the leukocytes of the mother and father, it is possible to determine the existing correspondences. This method of investigation is much more complicated. It allows you to obtain more accurate information than the study of blood groups. When paternity is established, the patients' chromosomes are also compared (using standards called allelic ladders). In this case, the genetic code of chromosomes provides reliable information.

Determining the moment of pregnancy

Additional information can be obtained when determining the moment of pregnancy. In this case, the evaluation of the gestational age and the stage of development of the fetus try to establish the date of conception as precisely as possible. Thus, an additional (but not always reliable) criterion is obtained.

Ability to fertilize

Of course, it is necessary to take into account the ability of a man to fertilize. The reliability of methods for establishing paternity and the use of these methods makes it almost impossible to exclude the possibility of paternity almost completely. However, in the case of a positive test result, the answer to the request indicates that the probability of paternity exists. Thus, the probability of paternity is determined on the basis of statistical methods. Recently, this probability can be calculated so accurately that the paternity of a man is practically possible to prove.

Anthropological examination of heredity
Today, in the establishment of paternity, this method of research has lost its significance and is used very rarely. The principle of this method is comparison of external data, for example, eyes, hair color, face shape.

Analysis of the inheritance of blood groups of the ABO system

The blood group (A, B, AB or O) is inherited by strict rules. There are five combinations of blood groups of the father-mother, in the presence of which the child can not be asserted that this man is not the father. Then there is a need for other methods of establishing paternity.
Blood test:
The first is the definition of the blood type
Second - Hereditary plasma proteins
Third - Inherited enzyme system
Fourth - Leukocyte antigens
Fifth - the moment of pregnancy, the biological-statistical calculation of the probability of paternity, an anthropological assessment of inherited characteristics, the ability to fertilize.