As you know, there are 4 blood groups. Blood type is inherited genetically, ie, the blood group of a child depends on the blood types of the parents. How to determine what blood group will the child?

Of course, the most reliable method  to find out the blood group of your baby is to do the analysis. By the results of the analysis, you will know both the blood group and the Rh factor. But if you want, you can "figure out \u0026 raquo; the blood group of a child even before his birth, knowing the blood groups of his parents.

System of division of blood groups, which is common currently, is called system AB0. According to this system, red blood cells (erythrocytes) of a person are characterized by the presence in them of special substances - antigens. The interaction of antigens influences, in particular, the compatibility of different blood groups in donors and recipients.

There are two categories of antigens — A and B. human blood may contain both antigens, one of them or neither. Depending on this there four blood groups :

  • I (0) — both antigen absent
  • II (A) to present the antigen to A
  • III (B) present the antigen to B
  • AB ( — ) are present in both antigen

But this information will help to determine what blood group the child? The fact that inheritance of blood group is the same as the inheritance of other characteristics  (for example, the color of the eyes and hair) and obeys the laws of genetics formulated by Mendel. Of course, these laws will not help to determine with 100% certainty what type of blood the child has, but a certain pattern can be traced:

  • Parents with I blood group will have children with I blood group.
  • Parents with II blood group will have children with I or II group of blood.
  • Parents with third blood group will have children with I or III blood group.
  • Parents with I and II or I and III children with one of these blood groups.
  • If one parent has IV blood group, the child can not be I group of blood.
  • If one parent has I group of blood, they can not be born child with IV group of blood.
  • Parents with II and III blood can be born children with any blood type.

For greater clarity, offer you a small table. In it, you can see what type of blood can be in a child with a certain combination of blood groups of parents.

Table inheritance of blood groups

In addition to blood groups, it is important to know it RH factor. Rhesus of blood is the protein (antigen) located on the surface of red blood cells. This protein is in most people, so they are considered Rh positive. Those who do not have this protein (and only about 15% of such people) are considered Rh negative.

Many people mistakenly believe that RH positive parents can only be born RH-positive child. In fact it is not. The fact that negative RH — is recessive, the "weak. This symptom may be present in the genotype, but "be suppressed \u0026 raquo; stronger sign - dominant.

If the genotype of both parents is present and dominant and recessive trait, then both will be positive RH, but there is 25% probability that their child will be RH negative as a result of combining two recessive traits.

Thus, if both parents or at least one of them has a positive RH factor, then can be born as RH-positive and RH-negative child. The same applies to couples in which one parent is RH-positive and RH-negative. Two parents with a negative RH factor can only be born RH-negative child .

As you can see, basic knowledge of genetics at the level of the school curriculum may help to determine what blood group the child — at least approximately. But if you don't want to remember you help our plate .

About how!
My parents have 2 +, I got 1-, how can this be?

Well, read the same article carefully, everything is written there)))) The tablet shows that parents with the 2nd blood group can have children with the first or second blood group, and about the Rh rhesus is written further - that parents with positive rhesus may well have a child with negative, it does not happen on the contrary

Hello, please tell me, my husband and I have positive and 2 positive, and a child 1 is negative, is this possible? I'm waiting for an answer.

and if I have 1 positive, my husband does not remember, it seems the second or third positive, and we have a child with a fourth negative, that I was replaced? a group of blood, and I and the child were determined several times - always converged.

at my daddy 4 +, and at mum 4, I was born with 1 +. Whether there can be such. I read the article that I can not.

[quote name=”the nike.vadim”]zdravst voice. please tell me may be such that Mom 1 blood type a positive and the father group 1 blood positive. may be such that the child 2 blood group a positive ?[/quotОТ

at parents 2ая, at me 3я

again the error analysis?(what do we have for medicine – all the mistakes)
or, again, “work up”?)) Oh well)) I so like her father)) and with the mother not only looks similar, but the character))
or an exception which? but what is the exception, if so many people claim it? (I judge not only this site)

Tell me please why my father has 4 positive and 2 has positive results, can a child be born with the first positive?