As we see, few couples manage to completely avoid strict geneticists - children with any blood type can only happen if one parent has a second group, and the other has a third. In all other cases there are restrictions.
Doesn't match?
Your blood type does not match the table value? So what should we do? Well, double-check the tests, and then? - I have three explanations for this situation (they are arranged in order of decreasing probability: first the most common case, last - the most exotic).
1. You are the result of cuckolding.(According to companies conducting research, a third of their male clients find out that they are raising other people’s children. Let’s make allowances for the fact that this third probably had some reason to contact geneticists, i.e. among them the likelihood of cuckoldry higher than the average - and we get 15-20%. About every fifth woman conceives a child from one, and says “he’s yours” to the other.)
2. You are an adopted child.(About 1.5% of the total number of children in Russia are adopted).
What to do?- Bow down to your adoptive parents and love them even more than before. Think about it: parents forgive their children for their terrible behavior, because “dear blood”, “he will grow up and become wiser”, “he himself is good, it’s his friends who have a bad influence on him” and so on, and similar nonsense. After all, if native If the child does not go too far, then his parents will not go anywhere, they will not put him further than the corner. But if you have been tolerated for so many years reception rooms parents... - They are holy people!
3. You are the result of a mutation.(The probability is about 0.001%.) There are two known mutations that can affect blood type:
- cis-position of genes A and B (allows a parent with blood group 4 to have a child with group 1, probability 0.001%);
- Bombay phenomenon (allows anything at all, but the probability among Caucasians is even lower - only 0.0005%).
(The mechanisms of these mutations are discussed in the elective.)
What to do? If you didn't like the first two options - believe in the third. One thousandth of one percent is, of course, one out of a hundred thousand people, not very common. But the courts, cunning ones, because of this one hundred thousandth, do not consider the blood type to be proof or refutation of paternity, give it to them.
For those who do not match: by which you can determine the relationship.
The everyday life of the laboratory, which is visited by non-matched parents, is described in the article
Inheritance of blood type and Rh factor by a child is carried out in accordance with genetic laws. During breastfeeding, anti-Rhesus antibodies are destroyed in the baby's stomach.
When planning a pregnancy or when a pregnant woman goes to an antenatal clinic for observation, one of the main tests is determination of group and Rh factor blood future parents. This is necessary for many reasons, one of which is the prevention of complications associated with incompatibility of the blood of the mother and fetus.
What are blood groups
Blood Difference different people consists in various combinations of specific protein complexes or in the absence of some of them. The classification of blood groups is carried out in accordance with the main polysaccharide-amino acid complexes built into the erythrocyte membrane. They are antigens, that is, foreign to another organism. In response to them, ready-made antibodies are produced or are already available that neutralize (destroy) the antigen.
If group antigens are located in erythrocytes, then antibodies are located in serum. When red blood cells with one blood group enter the plasma of a person with another group, they stick together and are destroyed by antibodies, which in mild cases manifests itself as so-called hemolytic (hemolysis - destruction) anemia or jaundice, and in severe cases - death of the body.
Normally, each person’s blood contains both antigens (agglutinogens) and antibodies (agglutinins), but not to their own agglutinogens. Conventionally, antigens are designated “A”, which correspond to antibodies “α” and “B” (antibodies - “β”). Thus, in accordance with this, four blood groups are determined, programmed in genetic code each person and designated by the AB0 system (0 - absence of antigens).
Inheritance of blood groups
According to the laws of genetics, separating chromosomes with the genetic set of one parent and combining them with the genetic set of the other in the offspring can give various combinations, on which the blood type of the fetus will depend. The probability of these combinations in the unborn child as a percentage is displayed in blood group inheritance table:
| Blood groups mother and father | I gr. baby (%) | II gr. baby (%) | III gr. baby (%) | IV gr. baby (%) |
| I ; I | 100 | 0 | 0 | 0 |
| I ; II | 50 | 50 | 0 | 0 |
| I ; III | 50 | 0 | 50 | 0 |
| I ; IV | 0 | 50 | 50 | 0 |
| II; II | 25 | 75 | 0 | 0 |
| II; III | 25 | 25 | 25 | 25 |
| II; IV | 0 | 50 | 25 | 25 |
| III; III | 25 | 0 | 75 | 0 |
| III; IV | 0 | 25 | 50 | 25 |
| IV; IV | 0 | 25 | 25 | 50 |
There are extremely rare exceptions when a child is determined to have a blood type that should not be there. This is called the Bombay phenomenon. It means the suppression of agglutinogens in the body of one of the parents, and his blood manifests itself as the properties of other groups. In this case, the suppressed gene is passed on to the child and manifests itself in him.
Due to the fact that antigens “A” and “B” are large molecules, they are not able to penetrate the placental barrier. During normal pregnancy different groups blood of the mother and fetus do not show themselves in any way. During birth, some of the mother's antibodies and antigens, due to placental abruption, can penetrate into the baby's blood, as a result of which the child develops hemolytic jaundice in the first days after birth. More often it is unexpressed and passes quickly, but in severe cases it can be dangerous and require intensive treatment.
Rh factor inheritance
The Rh factor is a lipoprotein that is present on the membrane of red blood cells in 85% of people. Its presence is indicated by "Rh+". The absence of this factor in 15% of people is designated as “Rh-”. Inheritance is carried out according to the following principle:
- If both parents have the Rh factor, the child also inherits the Rh factor of blood.
- In cases where it is absent from the parents, it is (usually) absent from the child.
- If one parent is Rh+ and the other is Rh negative, then the probability of inheritance is 50%.
- There are cases of inheritance after several generations, when a child may be born with the absence of the Rh factor even if both parents have it.
If the mother's blood is Rh negative and the child inherits the Rh positive gene, then the mother's blood produces antibodies. Arises Rhesus conflict, as a result of which there may be spontaneous abortions, develop difficult hemolytic disease newborns. This usually happens with repeated births, since antibodies are produced slowly during the first birth. And although the blood circulation of the fetus and mother are separate, in case of various infections and the pathological course of repeated pregnancy, existing antibodies easily penetrate into the blood of the fetus. To prevent their formation, a woman during her first birth is given anti-Rhesus immunoglobulin during the first three days.
Rhesus conflict does not arise:
- in the absence of the Rh factor in both parents;
- if the mother has Rh+ blood;The rhesus of the father and the fetus in this case does not matter;
- If the mother has Rh- blood and the father has Rh+ blood, the child inherits the genes of Rh-negative blood.
There is still no consensus regarding feeding breast milk with Rhesus conflict. Antibodies disappear from breast milk during the first 2 weeks, after which feeding is possible. But it is now believed that they are destroyed in the child’s digestive tract, despite its imperfections. Therefore, in maternity hospitals, breastfeeding is increasingly allowed from the first days.
It happens that a child’s blood type does not match the parent’s, which raises a lot of questions. This question was discovered by a scientist from Australia, K. Landsteiner. By studying the behavior of red blood cells in different people, he derived three AOB systems. In some, red blood cells are evenly distributed, in others they stick together. Genes with information about the presence or absence of agglutinogens are inherited. This is how I (OO), II (AA or AO) and III (BB or VO) appeared, and the fourth (AB) was discovered a little later. In all compounds, the first letter means information about the presence or absence of an agglutinogen that the child will receive from the mother, the second - from the father.
For example:
- with I (OO), antigens A and B are absent, therefore, if the father and mother have the first group, then the child will inherit it;
- one parent is with the first, the other with the second, then the offspring can be born with I or II;
- if the mother has II, and the father III, or vice versa, then the children will take any of the four;
- I and III – give only the first and third;
- if the parents have the fourth, then the baby will be born with any but the first, since both agglutinogens are present in the hereditary set. Thus, the child’s blood type may not coincide with the parent’s.
There are exceptions to all rules
Scientists have identified the fact of exclusion when both parents have IV (AB), and the child is born with I (OO). There are agglutinogens in the blood, but for some reason they do not appear; this phenomenon is still being studied. This fact is quite rare, and even rarer among the Caucasian race. The “Bombay phenomenon,” as it is called, appears more often among dark-skinned people, among Indians.
Blood transfusions can affect the genetic makeup, making it difficult to determine the exact group in a newborn baby. The agglutinogenic composition can be changed by many factors; it is quite difficult to determine this. Therefore, the blood group of parents and children cannot be called 100% interconnected and, moreover, paternity cannot be established using it. Initially, studies on the presence of heredity were not conducted, and are not being conducted now.
The most common are I and II, they are owned by almost 40% of the world's population. The rarest is IV, which only 3–5% of people have.
In addition to the group, blood is divided into Rh factor - positive and negative. Which also has its own rules and exceptions. A person with group I and negative Rh factor considered a universal donor. The most commonly required IV transfusion in the world is Rh positive.
A newborn baby's blood type is inherited from his mother and father. It is impossible to plan what it will be, but modern medicine allows us to calculate “options”. What blood type does the child have from his parents, a table with the Rh factor, the compatibility of a man with a woman when planning a pregnancy, the problem of Rh conflict - all this and much more will be discussed below.
How many blood types are there?
It would seem that all blood looks the same, but no, it contains specific red blood cell antigens, called A and B, due to which the main body fluid has special differences and is divided into types. Let's look at what blood types are:
- the first (0) – does not contain specific antigens;
- the second (A) – has only antigen A;
- third (B) – has only antigen B;
- the fourth (AB) – “can boast” of containing two antigens A and B.
What is the Rh factor (Rh)? This term refers to the protein lipoprotein, which is located on the surface of red blood cells. Based on its presence or absence, blood groups are divided into positive (Rh+) and negative (Rh-). Medical statistics show that only 15% of people have negative Rhesus, all the rest live with the positive group.
So, how many blood types does a person have? In case of allocation directly common types, then there are four of them, but if we take into account the fact that each of them can have both a positive and a negative indicator, then human blood can be divided into 8 subgroups.
Some statistics in percentages about people by blood type
As we have already found out, human plasma has 8 subgroups. An interesting fact is that the percentage of people by blood type differs significantly and has the following form:
Analyzing the statistics, we can say that Rh positive-factor is predominant and is present in 85% of the population. As for blood plasma, the first group is dominant in both the positive and negative subgroups. It is type I that is the main one, because it can be used for all other groups, although such blood itself does not accept any other subgroup.
The same table answers the question of which blood group is the rarest in the world. This is the fourth negative, which flows in the veins of only 0.4% of the world's population.
Parental compatibility, or what is meant by Rh conflict
It turns out that in order to conceive a child, potential parents must be compatible in blood type and Rh factor. Quite often, medical practice uses such a concept as parental incompatibility. What is it?
Incompatible parents
Many couples face such a problem as the lack of children. The examination reveals the incompatibility of a man and a woman, due to which the long-awaited first-born “does not work out.” To conceive a child, ideally the same Rh should be present, since otherwise, the course of labor may end in the following tragedies:
- If the woman is (-) and the man is (+), then the development of Rh conflict and fetal rejection with subsequent miscarriage is possible.
- When the woman is (+) and the man is (-), pregnancy is difficult, but if a miracle occurs, pregnancy continues without interruption.
Rhesus conflict, how not to lose a child
Typically, women with Rh- suffer from Rh conflict, since when conceived from an Rh+ owner, in 80% of cases the child receives the paternal Rh positive. A immune system A “minus” pregnant woman regards an embryo with a plus factor as pathogenic foreign cells and actively resists, in every possible way excluding its presence in the female body. The fetus's red blood cells are attacked by the antibodies produced by the pregnant woman, leading to the loss of red blood cells.
The embryo, fighting for life, produces new ones, which leads to an enlargement of the spleen and liver. Such rapid growth causes oxygen deprivation, leading to brain damage and, as a consequence, the death of the unborn child.
Expectant mother having Rh negative, should be under constant supervision of a gynecologist. She needs to be constantly tested for the presence and amount of antibodies produced.
The newborn's blood is immediately taken to determine the Rh factor. If he is Rh positive, then the “minus” woman is given anti-Rh immunoglobulin as quickly as possible. This is done in order to be able to bear and give birth to another healthy toddler in the future. Anti-Rhesus immunoglobulin is also administered if a pregnancy with Rh conflict ends in miscarriage or artificial birth in the later stages.
Blood type of the child from the parents, table with Rh factor
Blood type is a genetically inherited factor that is inherited from mom and dad. What blood type the child will have can be calculated. How? Now we'll explain everything.
Table of the possible blood type of a newborn based on the parents’ indicators:
The table clearly shows how specific erythrocyte antigens A and B are distributed. It should be noted that a parent with the first group cannot have a child with indicators of both A and B, even if the second parent has two of these antibodies. But those with IV(AB) will never get a child with group I(0). The most unpredictable are the results for parents who have all three types of indicators (A, B, 0) between them, for example, the mother has (A0), and the father (AB), here the child can inherit any of the four groups.
As for the Rh factor, it is inherited in a recessive-dominant manner. Rhesus positive is considered dominant, and rhesus minus is considered to be recessive, so if one of the parents has Rh+, then in up to 90% of cases the toddler will be born “positive”. Let's imagine the blood types of a child from his parents, in the form of a table with Rh factors.
| Mother's Rh factor | Dad's Rh factor | Possible Rh factor of the child in % |
| Rh+ | Rh+ | (Rh+) – 75%, (Rh-) – 25% |
| Rh+ | Rh- | (Rh+) – 50%, (Rh-) – 50% |
| Rh- | Rh+ | (Rh+) – 50%, (Rh-) – 50% |
| Rh- | Rh- | (Rh-) – 100% |
The times when mother III(B0) and father II(A0) born child IV(AB) were considered “fed up” have sunk into oblivion, today science has proven that human blood is inherited from parents, and its subgroup can be unpredictable and differ from parental. People preparing to become parents are simply obliged to know their Rhesus, since the compatibility of these indicators directly affects whether you will become happy parents or not.
