If the parents have 1 positive. Rules for the inheritance of blood groups. Their main features are

Blood groups are a set of properties of red blood cells, depending on the presence of certain types of carbohydrates and proteins that include the membranes of these cells. This indicator always remains the same, plays an important role in many areas of life and is inherited.

How many blood types are there? To date, there are four of them.

Influence on character

According to one theory (Ludwig Hirtzsfeld, Poland), all ancient people had the first group, since they ate raw meat and were predators by nature. Such people were inclined to eat heavy food of animal origin (meat), more aggressive.

With a gradual increase in the population and a change in the natural conditions of life, there were fewer opportunities to get meat, which forced people to switch to plant products. The digestive and immune systems had to adapt and changed slightly. This led to the emergence of a new - vegetarian blood type - the second.

The third arose in the conditions of mountain life, in the territory of present-day India and Pakistan. There people had to exist in difficult variable climatic conditions. Hence, its owners have such character traits as patience, endurance, purposefulness. To survive, they kept cattle, which added milk to their diet.

The fourth group - the youngest, was formed as a result of mixing the second and third. Due to its relatively recent introduction, only 6% of the population has one.

The preferences and character of each person depend on the blood type:

• I - purposeful and active people. They must eat food rich in proteins in order to gain strength and energy. Physical activity has a beneficial effect on their health, improves well-being. Among these people there are many leaders, as they are able to achieve their own, sociable, although at the same time emotional and ambitious.
• II - these people love order and harmony in everything, they are very responsible and diligent. They will work, no matter what, even to the detriment of their health. Emotionally stable, friendly, easy to get along with people. Their disadvantage is the inability to relax.
• III - the owners of this blood group easily adapt to different living conditions, like to travel, do not suffer from moving to another city or changing jobs. A calm and balanced life makes them bored and discouraged. They are very demanding both to themselves and to others. Among them are often creative personalities.
• IV - its owners are very amenable to emotions, think for a long time on one issue and often cannot make any definite decision. Tactful, fair and frank. For these qualities, they are loved and appreciated by others. These people have many friends.

Of course, many other factors also influence the personality, character, health and psyche of a person.

AB0 system

There are several systems by which blood groups are determined. The generally accepted system is AB0, which was developed in 1900 by the Austrian scientist K. Landsteiner. He found out that plasma contains antigen proteins: agglutinins a, b. Erythrocytes contain other antigens - agglutinogens A, B. It is interesting that a person can have only one type of protein: A or a, B or b.

What is an AB0 blood group? The presence of typical proteins or their absence determine the signs of blood, its belonging to a certain group. It is easy to calculate that 4 options for combining proteins are possible:

• A and B - the fourth group or AB;
• a and B - the third group or B;
• A and B - the second or A;
• a and b are the first or 0.

Rh(+) and Rh(-)

In addition to the group, an important characteristic of blood for life and health is the Rh factor (Rh). It is a protein (antigen) found on the surface of red blood cells. It was discovered by K. Landsteiner and A. Weiner in 1940.

In an analysis demonstrating the presence of the Rh factor in a person, the blood is considered Rh-positive and is designated as Rh (+). In the absence of this antigen, the blood is Rh-negative, which is designated as Rh (-). Most people have an Rh factor - approximately 85-90% of the population are Rh-positive. The presence of this protein varies by race. Among Indians and Asians, there are practically no Rh-negative representatives, but Europeans have about 15% of those.

The presence or absence of this antigen is inherited.

How to find out the group and Rh?

These data must be determined and entered into the patient's medical record and his passport, so that if an urgent transfusion is needed, no time is wasted on additional tests.

You can find out such information by passing an analysis at a polyclinic or at a donor center.

In a laboratory study, one of the four most popular methods is used to determine the blood group:

1. Standard - a blood sample is taken from a finger, after which the group is determined.
2. Double cross reaction - analysis is used to refine the results of the standard method.
3. Zolicloning - the reliability of the result approaches 100%.
4. Express method - the result is known already 3 minutes after adding the reagents. Often used in extreme conditions.

To determine the Rh factor, venous blood is taken. The result is known within 10 minutes. Rh blood is necessarily determined during pregnancy, preparation for a planned operation, in donors and recipients during transfusion.

You can find out your blood type at home using a special test (the results of the analysis, of course, are approximate). With a needle from the kit, you need to pierce your finger and drip blood into three places on the reagent card. Then, for the time specified in the instructions, wait for what will happen. In some places, small flakes may appear in the drop - this is erythrocytes sticking together (a phenomenon called agglutination). If this happens in the anti-A field, then the person has a second blood group; in the field of anti-B - the third; when both there and there - the fourth. If the drop remains transparent - this is the owner of the 1st group.

Transfusion

The blood of different groups may or may not be combined. This is of great importance in transfusion, because if the recipient and donor groups are incompatible, there will be serious complications, even death. In order to prevent this, an appropriate analysis is necessarily done in medical institutions.

• I - is universal, and its owners can be donors for anyone. Moreover, if Rh is negative, then it can be poured into both people with negative and positive Rh. If positive - only in the blood, the erythrocytes of which have protein. On the contrary, injection is impossible. For the first blood type, only the first is suitable, while a negative Rh is suitable for both positive and negative Rh, and a positive one is suitable only for owners of I (+).
• II - can be infused in those patients who have groups II and IV, but strictly on condition that the donor's Rh is negative. If he has an indicator II (+), then he can give his blood only to those who have II (+) or IV (+).
• III - if Rh is negative, then a person can become a donor only for people with III (+), III (-), IV (+), IV (-). III (+) is poured into those who also have III (+) or IV (+).
• IV - IV (-) to IV (-) and IV (+); IV (+) to IV (+).

Blood type compatibility rule:

• Blood with a negative Rh is allowed to be transfused to people with both Rh (-) and Rh (+). People with Rh-positive blood can only be donors for those with the same Rh. This is especially important to consider if the transfusion is not primary. When blood with a positive Rh factor enters the body of a person with a negative Rh factor, the recipient's immune system begins to produce antibodies against a protein that is unnatural for it. If re-transfused, they will work, which can lead to death.
• Those with the first group are ideal donors. Their blood is suitable for all people.
• People with the fourth group were the luckiest. Almost everyone can help them if they need a transfusion.

The best infusion option is when the blood of the donor and recipient is identical in group and Rh.

Blood and pregnancy

Compatibility of blood types of a man and a woman is important not so much at conception, as when carrying a fetus. Group compatibility is shown below:

• woman (I), man (I), compatibility (+);
• woman (I), man (II), compatibility (+);
• woman (I), man (III), compatibility (+);
• woman (I), man (IV), compatibility (+);
• woman (II), man (I), compatibility (-);
• woman (II), man (II), compatibility (+);
• woman (II), man (III), compatibility (-);
• woman (II), man (IV), compatibility (+);
• woman (III), man (I), compatibility (-);
• woman (III), man (II), compatibility (-);
• woman (III), man (III), compatibility (+);
• woman (III), man (IV), compatibility (+);
• woman (IV), man (I), compatibility (-);
• woman (IV), man (II), compatibility (-);
• woman (IV), man (III), compatibility (-);
• woman (IV), man (IV), compatibility (+).

This does not mean that couples with incompatible blood types will not be able to have children. But it will be much more difficult for them: more time may be spent on conception, pregnancy may be with complications, sometimes miscarriages occur.

More dangerous is the difference between parents by Rh-affiliation. It is desirable that the future father and mother both either have the corresponding antigen or not. Otherwise, a Rh conflict may occur, especially if the woman has a negative Rh, and the man is positive, and the baby has inherited Rh (+) from dad.

The body of a pregnant woman will perceive the fetus as a foreign body, and will try in every way to get rid of it. It will produce special antibodies that, penetrating the placenta, will adversely affect the child, leading to jaundice, anemia, and mental retardation. With a strong attack of antibodies, the fetus may even die. To prevent this from happening, a pregnant woman with Rh (-) needs to go to the gynecologist more often than the rest and take tests. Based on their results, the doctor sees the concentration of antibodies, and in the case when it exceeds the norm, the expectant mother is prescribed the introduction of drugs that suppress the production of antibodies.

The first pregnancy is relatively easy, but subsequent ones are more difficult, because anti-Rhesus antibodies are already present in the woman's body. For women with negative Rh, miscarriages and abortions are very dangerous - a second pregnancy may not take place.

Modern medicine has reached a high level and copes with the incompatibility of blood groups and Rh. The main thing is to identify them before pregnancy in order to undergo appropriate therapy. During the bearing of a child, it is important to visit a doctor in a timely manner and take all tests.

Heredity

The blood type of the child depends on which group the parents have. The baby gets the genes of the father and mother, which carry information about the presence of agglutinogens A and B in the blood or their absence. People with the first group do not have these; on the other hand, they possess agglutinogens A; from the third - B; and with the fourth A and B. What blood type the baby will have depends on his parents:

• parents: (I), (I), child (I);
• parents: (I), (II), child (I, II);
• parents: (I), (III), child (I, III);
• parents: (I), (IV), child (II, III);
• parents: (II), (I), child (I, II);
• parents: (II), (II), child (I, II);
• parents: (II), (III), child (I, II, III, IV);
• parents: (II), (IV), child (II, III, IV);
• parents: (III), (I), child (I, III);
• parents: (III), (II), child (I, II, III, IV);
• parents: (III), (III), child (I, III);
• parents: (III), (IV), child (II, III, IV);
• parents: (IV), (I), child (II, III); ;
• parents: (IV), (II), child (II, III, IV);
• parents: (IV), (III), child (II, III, IV);
• parents: (IV), (IV), child (II, III, IV).

The Rh factor is also inherited. So, if both the father and mother have Rh-negative blood, then the baby will also be Rh (-). When the resources of a woman and a man are different, then it is more likely that the child will inherit mother's Rh, but another option is also possible. With Rh-positive parents, the probability that the child's blood will be Rh (+) is from 75 to 95%.

As you can see, blood groups and Rh largely affect the life, condition and health of a person, the ability to have healthy offspring. These indicators cannot be selected or changed, but it is necessary to do an analysis in order to know your data. This will help you be prepared for any situation.

How to determine the blood type of a child by parents

• How to recognize a group in children
• How to determine the Rh factor
• Gender of the baby according to the blood type of the parents
• Gender by Rh factor
• Conclusion

According to the classification adopted today, blood is divided into four groups: I (0) - the first, II (A) - the second, III (B) - the third, IV (AB) - the fourth. They are distinguished by the presence or absence of certain antigens on the surface of red blood cells. If red cells do not contain any antigens, then this is the first group, if they contain only antigen A - the second, only B - the third, both antigens (A and B) - the fourth. In addition, red blood cells can contain on their surface a specific lipoprotein called the Rh factor, and then the blood will be Rh-positive (Rh +). This complex protein is found in red cells in only 85% of people, while the rest do not have it. The remaining 15% are Rh negative (Rh-).

How to recognize a group in children?

Many future parents are interested in knowing what type of blood their offspring will have and how this information is transmitted. Inheritance occurs according to the laws of genetics, which are well studied today. In the AB0 system, three genes are responsible for the group - A, B and 0, of which A and B are dominant, 0 is recessive. Each person receives one gene from their mother and one from their father. Genotypes in a simplified form can be represented as follows:

• The first (I) is 00. A person will pass only 0 to his offspring.
• The second (II) is AA or A0. Children can get either A or 0.
• The third (III) is BB or B0. Either B or 0 is inherited.
• Fourth (IV) - AB. Children can get either A or B.

Based on the blood type of the parents and the knowledge of some simple and understandable patterns of distribution of hereditary traits in the offspring, formulated in Mendel's law, it is possible to calculate the possible variants of the blood of future children:

1. If the pair has I (0), the heirs will have the same one, and there cannot be another.
2. If one has I (0) and the other II (A), the children will have I or II.
3. If one parent has I (0) and the other has III (B), the offspring may have either I or III.
4. If one has I (0), the other has IV (AB), the children will inherit II or III.
5. If both mother and father have II (A), the child will receive either II or I.
6. If one has II (A), the other has III (B), children can have any with an equal degree of probability.
7. If one parent has II (A) and the other IV (AB), the offspring may have II, III, or IV.
8. If both parents have III (B), the heirs will receive III or I.
9. If one has III (B), the other has IV (B), the children will have II, III or IV.
10. If both are owners of IV (AB), the offspring will inherit II, III, or IV.

You can determine the percentage of the probability of inheritance of a particular blood, taking into account the combinations of genes in mom and dad. Examples:

1. What kind of blood can a child have if the future mother has the second, the father has the fourth? A woman in this case can have the following combinations: AA and A0, a man - only one option - AB. The offspring can inherit the following variants: in the first case - AA, AB, AA, AB, in the second - AA, AB, 0A, 0B. When the AA genes are combined in the mother, children can get the second and fourth with a probability of 50 to 50. With the A0 genotype in a woman, they will have the second with a probability of 50%, the third with a probability of 25% and the fourth with a probability of 25%.
2. How to determine the group of the unborn child, if the mother has the first, the father has the third? In this case, a woman has only one combination - 00, a man has two - BB and B0. The offspring can inherit the following combinations: 0B, 0B, 0B, 0B and 0B, 00, 0B, 00. Thus, if the father has the genotype BB, then the children will have blood of the third group by 100%, if the genotype is B0, then the probability of the first and the third is 50%.

More clearly, the results of calculations can be presented using a table.

We can say about some patterns of inheritance:

1. If both in a pair have no antigens on the surface of red cells (neither A nor B), then all their children will inherit this trait, that is, they will have only group I, and no other. In this case, you can determine the group of the child absolutely accurately, 100%.
2. If one in a pair has I(0) and the other II(A), then the children will either have I(0) or II(0). Similarly, for a pair with I (0) and III (B) - the offspring will inherit I (0) or III (B).
3. It is impossible to predict what kind of blood the children will have if one of the spouses has II (A) and the other has III (B). In this case, any options are possible.
4. People with IV (AB) cannot have children with I (0), no matter what blood the partner has.

How to determine the Rh factor?

According to this system, there are only two types: Rh-negative and Rh-positive. Responsible for the inheritance of the Rh gene, which can have two alleles D and d, where D is the presence of Rh, d is its absence: Rh (D) is dominant, Rh (d) is recessive. Thus, it becomes clear that an Rh-positive person has the DD or Dd gene, while an Rh-negative person only has dd. If one parent has the DD gene, then all children will be Rh positive. If both mother and father are Rh-negative, that is, both have the dd genotype, then all children will have Rh-negative only. If future parents have Rh (+), while their genes are Dd, then they can have children with both positive Rh and negative. In this case, combinations are possible: DD, Dd, dd.

Gender of the baby according to the blood type of the parents

Most expectant mothers and fathers are interested in who will be born - a boy or a girl, and whether it can be determined by the blood of their parents. Such a theory does exist, but it has no scientific justification, so it is hardly worth trusting. It is used both at the stage of preparation for conception, and after the pregnancy has already begun.

According to this method, the probability of having children of one sex or another is as follows:

1. A woman with the first group has a high probability of having a girl from a man from the first and third, a boy from a man from the second and fourth.
2. If the mother has the second, the girl will be born in a pair with a man with the second and fourth, the boy - from the father with the first and third.
3. A woman with a third is more likely to give birth to a girl from a man with a first. In other cases, more likely, there will be a son.
4. A mother with a fourth will have a daughter if a man with a second becomes the father, in other cases she should expect a boy.

Gender by Rh factor

This method also has no scientific confirmation. Determining gender by this indicator is very simple. According to this theory, the birth of a daughter should be expected if the parents or both are Rh positive, or both are negative. In other cases, the birth of a son is assumed.

Conclusion

Nowadays, a lot can be learned about future offspring even before their birth. Modern medicine allows at the stage of pregnancy planning to determine the likelihood of developing genetic diseases based on a blood test. Thus, future parents can avoid various unpleasant consequences and give birth to healthy babies. Determining the blood type of children by parents using existing tables cannot be considered accurate, one can only assume possible options. To find out this information, for sure, it will turn out only after conducting laboratory tests.

After learning about pregnancy, women seek to get as much information as possible about their future baby. It is, of course, impossible to determine what character or eye color he will inherit. However, when referring to the genetic laws, you can easily find out what type of blood the child will have.

This indicator is directly related to the properties of the blood fluid of mom and dad. To understand how inheritance occurs, it is necessary to study the ABO system and other laws.

What groups exist

A blood group is nothing more than a structural feature of a protein. It is not subject to any changes regardless of the circumstances. That is why this indicator is considered as a constant value.

Its discovery was carried out in the 19th century by the scientist Karl Landsteiner, thanks to whom the ABO system was developed. According to this theory, the blood fluid is divided into four groups, which are now known to every person:

• I (0) - no antigens A and B;
• II (A) - antigen A is present;
• III (B) - B takes place;
• IV(AB) - both antigens exist at once.

The presented ABO system contributed to a complete change in the opinion of scientists regarding the nature and composition of the blood fluid. In addition, the mistakes that were made earlier during transfusion and manifested by the incompatibility of the patient's and donor's blood were no longer allowed.

There are three groups represented in the mn system: N, M, and MN. If both parents have M or N, the child will have the same phenotype. The birth of children with MN can only be if one parent has M, the second has N.

Rh factor and its meaning

This name was given to a protein antigen that is present on the surface of red blood cells. It was first discovered in 1919 in monkeys. A little later, the fact of its presence in humans was confirmed.

The Rh factor consists of more than forty antigens. They are marked in numerical and alphabetic terms. In most cases, antigens such as D, C and E are found.

According to statistics, in 85% of cases, the Europeans have a positive Rh factor, and 15 percent - negative.

Mendel's laws

In his laws, Gregor Mendel clearly describes the pattern of inheritance of certain traits in a child from parents. It was these principles that were taken as a solid basis for the creation of such a science as genetics.. In addition, it is they that must be considered first of all in order to calculate the blood type of the unborn baby.

Among the main principles according to Mendel are the following:

• if both parents have 1 group, then the child will be born without the presence of antigens A and B;
• if the father and mother have 1 and 2, then the baby can inherit one of the presented groups; the same principle applies to the first and third;
• parents have a fourth - a child develops any, except for the first.

The blood type of a child according to the blood type of the parents cannot be predicted in a situation where mom and dad have 2 and 3.

How is inheritance from parents to children

All human genotypes are designated according to the following principle:

• the first group is 00, that is, the 1st zero in the baby is transmitted from the mother, the other from the father;
• the second - AA or 0A;
• the third is B0 or ​​BB, that is, in this case, the transfer from the parent will be B or 0 of the indicator;
• fourth - AB.

The inheritance of a blood group from parents by a child occurs according to generally accepted genetic laws. As a rule, the parental genes are passed on to the baby. They contain all the necessary information, for example, the Rh factor, the presence or absence of agglutinogens.

How is the Rh factor inherited?

The determination of this indicator is also carried out on the basis of the presence of a protein, which, as a rule, is present on the surface of the erythrocyte composition. If the red blood cells contain it, then the blood will be Rh positive. In the case when the protein is absent, a negative Rh factor is noted.

According to statistics, the ratio of positive and negative indicators will be 85 and 15%, respectively.

The inheritance of the Rh factor is carried out according to the dominant trait. If two parents do not have an antigen that determines this indicator, then the child will also have a negative value. If one of the parents is Rh positive and the other is Rh negative, then the probability that the child can act as a carrier of the antigen is 50%.

If the mother and father have factors with a “+” sign, then in 75 percent of cases the baby inherits a positive Rh. It is also worth noting that in this case there is a high probability that the child will receive the genes of a close relative who has a negative value of this indicator.

For a more accurate understanding of how the Rh factor is inherited, you can consider in detail the data shown in the table below.

How to find out the blood type of an unborn baby

To determine whose blood type a child inherits, specialists have developed a special table that allows each future parent to make predictions on their own.

With a careful study of the tabular results, the following decoding is possible:

• the blood of parents and children will be the same only if mom and dad have the first group;
• if the second group is present in both parents, the child will inherit 1 or 2;
• when one parent has the first, the baby cannot be born with the fourth;
• if mom or dad has the third group, then the probability that the child will inherit the same, the same as in the previous described cases.

If the parents have 4 groups, the baby will never have the first.

Could there be an incompatibility?

In the second half of the 20th century, after the definition of group 4 and the recognition of Rh factors, a theory describing compatibility was also developed. Initially, this concept was used exclusively for transfusion.

The injected blood fluid must not only correspond to the group, but also have the same Rh factor. If this is not adhered to, conflict arises, which ultimately leads to death. Such consequences are explained by the fact that when incompatible blood enters, the destruction of red blood cells occurs, which leads to a cessation of oxygen supply.

Scientists have proven that the first is considered the only universal group. It can be transfused to any person, regardless of the group affiliation of the blood composition and Rhesus. The fourth is also used in all situations, but with the condition that the patient will only have a positive Rh factor.

When pregnancy occurs, the moment is also not excluded that a blood conflict between a child and a woman is possible. Such situations are predicted in two cases:

1. The woman's blood is negative, while the father's is positive. Most likely, the baby will also have a value with a “+” sign. This means that when it enters the mother's body, antibodies will begin to be produced in her blood fluid.
2. If the expectant mother has the first group, and the man has any other, except for 1. In this case, if the child does not also inherit the 1st group, a blood conflict is not ruled out.

When the first situation arises, everything may end in not the most favorable consequences. When the fetus inherits a positive Rh, the immune system of a pregnant woman will perceive the child's red blood cells as foreign and seek to destroy them.

As a result, when the child's body loses red blood cells, it will produce new ones, which gives a very noticeable load on the liver and spleen. Over time, oxygen starvation occurs, the brain is damaged, and fetal death is also possible.

If the pregnancy is the first, then the Rh conflict can be avoided. However, with each successive, the risks increase significantly. In such a situation, a woman should constantly be observed by a specialist. She will also need to do blood tests for antibodies quite often.

Immediately after the baby is born, the blood fluid group and its Rh factor are determined. With a positive value, anti-Rhesus immunoglobulin is administered to the mother.

Such actions help prevent adverse consequences when conceiving a second and subsequent children.

The second option does not pose a threat to the life of the baby. In addition, it is diagnosed extremely rarely and does not differ in the complex course of the process. An exception is hemolytic disease. If you suspect the development of this pathology, it will be necessary to regularly take tests.. In this case, in order for the birth to be successful, the most favorable terms are 35-37 weeks.

Most experts argue that with the highest value of father's blood relative to mother's, the probability of having a healthy and strong child is almost equal to 100 percent.

Conflicts due to incompatibility in the blood type of parents are not such a rare occurrence, but not as dangerous as with a mismatch in the Rh factor.

If you conduct a survey in a timely manner, regularly visit a gynecologist and do not ignore the instructions of the attending physician, this will increase the likelihood of a successful conception, bearing and birth of a baby.

The inheritance of blood types is not such a complicated science. Knowing all the subtleties and nuances, you can find out what group and Rhesus he will have even before the baby is born.

Pregnancy is a time of joyful expectations and anticipation. Parents make plans for an heir, choose a name. But first, the future father and mother want to know the child's gender, hair color, eye tone, and how the child's blood type is inherited from the parents.

What are the blood types?

The Austrian biologist and botanist Gregor Mendel is considered the founder of the study of genes. His research concerned the transmission of maternal and paternal genes to the child, as a result of which he came to the conclusion about certain signs of inheritance. These conclusions he formulated into laws. Mendel found that the heir must have one maternal gene, and the second paternal. Moreover, the inherited trait can be dominant (will appear) or recessive (will not appear). Mendel found that genes A and B are dominant, and gene 0 is recessive.

A blood group is a complex of red blood cells with a certain set of antigens. They are characterized by special organic substances having a carbonyl and hydroxyl group (carbohydrates) and high-molecular organic substances connected by a peptide bond (proteins) located in the shell of red blood cells.

According to the totality of the properties of red blood cells, people are distinguished by belonging to any blood group. It is personal for everyone, it is given from birth and does not change anymore. Blood is divided into 4 groups according to the AB0 system and into two groups according to the Rh factor system.

The first blood group is I (0). A characteristic feature of this group is the absence of substances that the body considers as foreign or dangerous. It is not easy for people with such a group to find a donor, since the first group is compatible with the same group. But it is universal for everyone else.

II (A) - the second blood group. The erythrocytes of this group contain an enzyme that transfers saccharide residues (A) and agglutinin beta. People with such a group are recipients for groups 0 and A.

III (B) - the third group. It is characterized by the presence of alpha antibodies and B antigens. People with such blood can act as a donor for groups III and IV.

IV (AB) - the fourth. This group does not contain antibodies. For people with such a group, any of the groups will be suitable for transfusion.

Of course, many factors are taken into account when transfusing blood, but the group remains one of the main ones.

Rh system: what Rh will the child take?

The Rh factor is an indicator of the presence or absence of a substance considered as foreign (protein) on the plane of erythrocytes. Rhesus is important in the formation of a pathological condition in a newborn - the breakdown of red blood cells ().

Rhesus, like the group, is congenital and does not change. It is taken into account in two situations:

• in preparation for various medical operations, donation;
• during pregnancy with placental exposure. If the expectant mother has a negative Rh factor, and the father, on the contrary, has a plus, during pregnancy the woman is under special control for spontaneous abortion. In Rh-conflict, the mother's body rejects the fetus with Rh-positive blood, as it considers it foreign.

How does blood type affect health?

Various studies have made it possible to determine the relationship between blood type and susceptibility to certain diseases:

• the threat of the appearance of a slowly progressive chronic neurological disease Parkinson's disease in the owners of the third group is higher than in the rest;
• people with all blood groups except the first are predisposed to heart disease.
• the owners of the third group are less likely to get plague.
• stomach ulcers are much more common in owners of the first blood group.

Experts have compiled special diets based on blood type, which contribute to the fastest recovery.

How exactly is a blood type inherited from a child's parents?

If the parents have the same blood type, then it is not at all necessary that the child will have just such a set of red blood cells. This is due to a recessive gene (O).

If the mother has the first blood group (I) and the father (I), then the probability for the child to be born with the first blood group is 100%.

Both parents (II) second group: child's blood (II) - 94%, (I) - 6%;

Both parents (III) third group: child group (III) - 94%, (I) - 6%;

Parents with the fourth group (IV): the child's group (IV) - 50%, (III) - 25%, (II) - 25%.

What blood type the child will have in the case of different blood types of father and mother can be clearly seen in the table:

The inheritance system of the Rh factor looks like this:

• if a negative Rh is inherent in both parents, then the child will have exactly the same;
• if, on the contrary, it is positive for both parents, then the probability of a positive Rh in a child is 94%, and this suggests that Rh-positive parents may well have an Rh-negative child;
• if parents have different Rh, then 75% of children inherit a positive Rh.

It is important to remember that calculations using various tables, schemes are only an assumption, the exact blood type and Rh factor are determined by a special laboratory analysis.

Compatibility of blood types of future mothers and fathers

One of the first tests that a pregnant woman takes is the blood type and Rh factor. The resistance of the Rh factors of the parents is fully reflected in the health of the baby, since there is a possibility that a conflict situation will arise.

This is necessary to know in order to smooth out the humoral response of an Rh-negative mother to the antigens of an Rh-positive fetus. In the event that the baby inherited a positive Rh from the father, and the mother is Rh-negative, this can lead to hemolytic diseases of the heir.

The risks for a baby with a Rh conflict increase with each new physiological process (pregnancy), even if it did not end in childbirth (abortion, ectopic pregnancy).

Some life situations (upcoming surgery, pregnancy, desire to become a donor, etc.) require an analysis, which we used to call simply: “blood type”. Meanwhile, in the broad sense of this term, there is some inaccuracy here, since most of us mean the well-known AB0 erythrocyte system, described in 1901 by Landsteiner, but do not know about it and therefore say “blood test per group”, thus separating, another important system.

Karl Landsteiner, who was awarded the Nobel Prize for this discovery, continued to work throughout his life on the search for other antigens located on the surface of red blood cells, and in 1940 the world learned about the existence of the Rhesus system, which occupies the second place in importance. In addition, scientists in 1927 found protein substances secreted into the erythrocyte systems - MNs and Pp. At that time, this was a huge breakthrough in medicine, because people suspected that it could lead to the death of the body, and someone else's blood could save lives, so they made attempts to transfuse it from animals to humans and from humans to humans. Unfortunately, success did not always come, but science has been steadily moving forward and at the present time we are only out of habit talking about the blood type, meaning the AB0 system.

What is a blood type and how did it become known?

The determination of the blood group is based on the classification of genetically determined individually specific proteins of all tissues of the human body. These organ-specific protein structures are called antigens(alloantigens, isoantigens), but they should not be confused with antigens specific for certain pathological formations (tumors) or infection-causing proteins entering the body from outside.

The antigenic set of tissues (and blood, of course), given from birth, determines the biological individuality of a particular individual, which can be a person, any animal, or a microorganism, that is, isoantigens characterize group-specific features that make it possible to distinguish these individuals within their species.

The alloantigenic properties of our tissues began to be studied by Karl Landsteiner, who mixed the blood (erythrocytes) of people with the sera of other people and noticed that in some cases, erythrocytes stick together (agglutination), while in others the color remains homogeneous. True, at first the scientist found 3 groups (A, B, C), the 4th blood group (AB) was discovered later by the Czech Jan Jansky. In 1915, the first standard sera containing specific antibodies (agglutinins) that determined group affiliation were already obtained in England and America. In Russia, the blood group according to the AB0 system began to be determined in 1919, but the digital designations (1, 2, 3, 4) were put into practice in 1921, and a little later they began to use alphanumeric nomenclature, where antigens were designated in Latin letters (A and C), while antibodies are Greek (α and β).

It turns out there are so many...

To date, immunohematology has replenished with more than 250 antigens located on erythrocytes. The major erythrocyte antigen systems include:

These systems, in addition to transfusiology (blood transfusion), where the main role belongs to AB0 and Rh, most often remind of themselves in obstetric practice.(miscarriages, stillbirths, the birth of children with severe hemolytic disease), however, it is not always possible to determine the erythrocyte antigens of many systems (except for AB0, Rh), due to the lack of typing sera, the production of which requires large material and labor costs. Thus, when we talk about blood groups 1, 2, 3, 4, we mean the main antigenic system of erythrocytes, called the AB0 system.

Table: possible combinations of AB0 and Rh (blood groups and Rh factors)

In addition, approximately from the middle of the last century, antigens began to be discovered one after another:

1. Platelets, which in most cases repeated the antigenic determinants of erythrocytes, however, with a lesser degree of severity, which makes it difficult to determine the blood group on platelets;
2. Nuclear cells, primarily lymphocytes (HLA - histocompatibility system), which opened up wide opportunities for organ and tissue transplantation and solving some genetic problems (hereditary predisposition to a certain pathology);
3. Plasma proteins (the number of described genetic systems has already exceeded a dozen).

The discoveries of many genetically determined structures (antigens) made it possible not only to take a different approach to determining the blood group, but also to strengthen the position of clinical immunohematology in terms of fight against various pathological processes, made possible safe, as well as transplantation of organs and tissues.

The main system that divides people into 4 groups

The group affiliation of erythrocytes depends on group-specific antigens A and B (agglutinogens):

• Containing in its composition protein and polysaccharides;
• Closely associated with the stroma of red blood cells;
• Not related to hemoglobin, which does not participate in the agglutination reaction in any way.

By the way, agglutinogens can be found on other blood cells (platelets, leukocytes) or in tissues and body fluids (saliva, tears, amniotic fluid), where they are determined in much smaller quantities.

Thus, on the stroma of erythrocytes of a particular person, antigens A and B can be found.(together or separately, but always forming a pair, for example, AB, AA, A0 or BB, B0) or not to be found there at all (00).

In addition, globulin fractions (agglutinins α and β) float in the blood plasma. compatible with the antigen (A with β, B with α), called natural antibodies.

Obviously, in the first group, which does not contain antigens, both types of group antibodies, α and β, will be present. In the fourth group, normally, there should not be any natural globulin fractions, because if this is allowed, antigens and antibodies will begin to stick together: α will agglutinate (glue) A, and β, respectively, B.

Depending on the combinations of options and the presence of certain antigens and antibodies, the group affiliation of human blood can be represented as follows:

• 1 blood group 0αβ(I): antigens - 00(I), antibodies - α and β;
• 2 blood group Aβ(II): antigens - AA or A0(II), antibodies - β;
• 3 blood group Bα (III): antigens - BB or B0 (III), antibodies - α
• 4 blood group AB0 (IV): antigens only A and B, no antibodies.

It may surprise the reader to learn that there is a blood type that does not fit into this classification. . It was discovered in 1952 by a resident of Bombay, which is why it was called "Bombay". Antigen-serological variant of erythrocyte type « bombey» does not contain antigens of the AB0 system, and in the serum of such people, along with natural antibodies α and β, anti-H are found(antibodies directed to substance H, which differentiates antigens A and B and does not allow their presence on the stroma of erythrocytes). Subsequently, "Bombay" and other rare types of group affiliation were found in different parts of the world. Of course, you cannot envy such people, because in case of massive blood loss, they need to look for a saving environment all over the globe.

Ignorance of the laws of genetics can cause tragedy in the family

The blood group of each person according to the AB0 system is the result of the inheritance of one antigen from the mother, the other from the father. Receiving hereditary information from both parents, a person in his phenotype has half of each of them, that is, the blood group of the parents and the child is a combination of two traits, therefore it may not coincide with the blood type of the father or mother.

Mismatches between the blood types of parents and the child give rise to doubts and suspicions in the minds of individual men about the infidelity of their spouse. This happens due to the lack of elementary knowledge of the laws of nature and genetics, therefore, in order to avoid tragic mistakes on the part of the male, whose ignorance often breaks happy family relationships, we consider it necessary to once again explain where this or that blood type comes from in the child according to the AB0 system and bring examples of expected results.

Option 1. If both parents have the first blood type: 00(I) x 00(I), then the child will have only the first 0(I) Group, all others are excluded. This is because the genes that synthesize antigens of the first blood group - recessive, they can only manifest themselves in homozygous state when no other gene (dominant) is suppressed.

Option 2. Both parents have the second group A (II). However, it can be either homozygous, when two traits are the same and dominant (AA), or heterozygous, represented by a dominant and recessive variant (A0), so the following combinations are possible here:

• AA(II) x AA(II) → AA(II);
• AA(II) x A0(II) → AA(II);
• A0 (II) x A0 (II) → AA (II), A0 (II), 00 (I), that is, with such a combination of parental phenotypes, both the first and second groups are likely, third and fourth are excluded.

Option 3. One of the parents has the first group 0 (I), the other has the second:

• AA(II) x 00(I) → A0(II);
• A0(II) x 00(I) → A0(II), 00(I).

Possible groups in a child are A (II) and 0 (I), excluded - B(III) and AB(IV).

Option 4. In the case of a combination of two third groups inheritance will follow option 2: a possible membership would be the third or first group, while the second and fourth will be excluded.

Option 5. When one of the parents has the first group, and the second the third, inheritance is the same option 3– the child may have B(III) and 0(I), but excluded A(II) and AB(IV) .

Option 6. Parent groups A(II) and B(III ) when inherited, they can give any group membership of the system AB0(1, 2, 3, 4). The emergence of 4 blood types is an example codominant inheritance when both antigens in the phenotype are equal and equally manifest themselves as a new trait (A + B = AB):

• AA(II) x BB(III) → AB(IV);
• A0(II) x B0(III) → AB(IV), 00(I), A0(II), B0(III);
• A0(II) x BB(III) → AB(IV), B0(III);
• B0(III) x AA(II) → AB(IV), A0(II).

Option 7. With a combination of the second and fourth groups parents can the second, third and fourth group in a child, the first one is excluded:

• AA(II) x AB(IV) → AA(II), AB(IV);
• A0(II) x AB(IV) → AA(II), A0(II), B0(III), AB(IV).

Option 8. A similar situation develops in the case of a combination of the third and fourth groups: A(II), B(III) and AB(IV) will be possible, and the first one is excluded.

• BB(III) x AB(IV) → BB(III), AB(IV);
• B0(III) x AB(IV) → A0(II), BB(III), B0(III), AB(IV).

Option 9 - the most interesting. Presence of blood types 1 and 4 in parents as a result, it turns into the appearance of a second or third blood type in a child, but never – first and fourth:

• AB(IV) x 00(I);
• A + 0 = A0(II);
• B + 0 = B0 (III).

Table: child's blood type based on parents' blood types

Obviously, the statement about the same group affiliation in parents and children is a delusion, because genetics obeys its own laws. As for determining the child's blood group according to the group affiliation of the parents, this is only possible if the parents have the first group, that is, in this case, the appearance of A (II) or B (III) will exclude biological paternity or motherhood. The combination of the fourth and first groups will lead to the emergence of new phenotypic traits (group 2 or 3), while the old ones will be lost.

Boy, girl, group compatibility

If in the old days, for a birth in the family of an heir, they put the reins under the pillow, but now everything is put almost on a scientific basis. Trying to deceive nature and “order” the sex of the child in advance, future parents perform simple arithmetic operations: they divide the father’s age by 4, and the mother’s age by 3, whoever has the largest balance wins. Sometimes this coincides, and sometimes it is disappointing, so what is the probability of getting the desired gender using calculations - official medicine does not comment, therefore it is up to everyone to calculate or not, but the method is painless and absolutely harmless. You can try, what if you get lucky?

for reference: what really affects the sex of the child - combinations of X and Y chromosomes

But the compatibility of the blood type of the parents is a completely different matter, and not in terms of the sex of the child, but in the sense of whether he will be born at all. The formation of immune antibodies (anti-A and anti-B), although rare, can interfere with the normal course of pregnancy (IgG) and even feeding the baby (IgA). Fortunately, the AB0 system does not interfere with reproduction so often, which cannot be said about the Rh factor. It can cause miscarriage or the birth of babies with, the best consequence of which is deafness, and in the worst case, the child cannot be saved at all.

Group affiliation and pregnancy

Determining the blood group according to the AB0 and Rhesus (Rh) systems is a mandatory procedure when registering for pregnancy.

In the case of a negative Rh factor in the expectant mother and the same result in the future father of the child, you don’t have to worry, because the baby will also have a negative Rh factor.

Do not immediately panic a "negative" woman and first(abortions and miscarriages are also considered) pregnancies. Unlike the AB0 (α, β) system, the Rhesus system does not have natural antibodies, so the body still only recognizes the “foreign”, but does not react to it in any way. Immunization will occur during childbirth, therefore, so that the woman’s body does not “remember” the presence of foreign antigens (Rh factor is positive), on the first day after childbirth, a special anti-Rhesus serum is introduced to the puerperal, protecting subsequent pregnancies. In the case of a strong immunization of a "negative" woman with a "positive" antigen (Rh +), compatibility for conception is a big question, therefore, without looking at long-term treatment, the woman is haunted by failures (miscarriages). The body of a woman with a negative Rh, having once “remembered” a foreign protein (“memory cell”), will respond with active production of immune antibodies at subsequent meetings (pregnancy) and will in every possible way reject him, that is, her own desired and long-awaited child, if he has positive Rh factor.

Compatibility for conception sometimes should be borne in mind in relation to other systems. By the way, AB0 is quite loyal to the presence of a stranger and rarely gives immunization. However, there are known cases of the emergence of immune antibodies in women with AB0-incompatible pregnancy, when the damaged placenta allows access to the fetal erythrocytes in the mother's blood. It is generally accepted that the highest probability of isoimmunization of a woman is introduced by vaccinations (DPT), which contain group-specific substances of animal origin. First of all, such a feature was noticed for substance A.

Probably, the second place after the Rhesus system in this regard can be given to the histocompatibility system (HLA), and then to Kell. In general, each of them is sometimes able to present a surprise. This is because the body of a woman who has a close relationship with a certain man, even without pregnancy, reacts to his antigens and produces antibodies. This process is called sensitization. The only question is to what level sensitization will reach, which depends on the concentration of immunoglobulins and the formation of antigen-antibody complexes. With a high titer of immune antibodies, compatibility for conception is in great doubt. Rather, we will talk about incompatibility, requiring huge efforts of doctors (immunologists, gynecologists), unfortunately, often in vain. A decrease in titer over time also does little to reassure, the “memory cell” knows its task ...

Video: pregnancy, blood type and Rh conflict

Compatible blood transfusion

In addition to compatibility for conception, no less important is transfusion compatibility where the AB0 system plays a dominant role (transfusion of blood that is incompatible with the AB0 system is very dangerous and can be fatal!). Often a person believes that the 1 (2, 3, 4) blood type of him and his neighbor must be the same, that the first will always suit the first, the second - the second, and so on, and in some circumstances they (neighbors) can help each other friend. It would seem that a recipient with a 2nd blood group should accept a donor of the same group, but this is not always the case. The thing is that antigens A and B have their own varieties. For example, antigen A has the most allospecific variants (A 1, A 2, A 3, A 4, A 0, A X, etc.), but B is not much inferior (B 1, B X, B 3, B weak, etc. .), that is, it turns out that these options may simply not be combined, even though when analyzing blood for a group, the result will be A (II) or B (III). Thus, given such heterogeneity, can one imagine how many varieties can a 4th blood group have, containing both A and B antigen in its composition?

The statement that blood type 1 is the best, as it suits everyone without exception, and the fourth accepts any, is also outdated. For example, some people with 1 blood type are for some reason called a "dangerous" universal donor. And the danger lies in the fact that, having no antigens A and B on erythrocytes, the plasma of these people contains a large titer of natural antibodies α and β, which, entering the bloodstream of a recipient of other groups (except the first), begin to agglutinate the antigens located there (A and / or AT).

blood type compatibility during transfusion

At present, transfusion of different types of blood is not practiced, with the exception of some cases of transfusions that require special selection. Then the first Rh-negative blood group is considered universal, the erythrocytes of which are washed 3 or 5 times to avoid immunological reactions. The first blood group with a positive Rh can be universal only in relation to Rh (+) erythrocytes, that is, after determining for compatibility and washing the erythrocyte mass can be transfused to a Rh-positive recipient with any group of the AB0 system.

The most common group in the European territory of the Russian Federation is the second - A (II), Rh (+), the rarest - 4 blood group with negative Rh. In blood banks, the attitude towards the latter is especially reverent, because a person with a similar antigenic composition should not die just because, if necessary, they will not find the right amount of erythrocyte mass or plasma. By the way, plasmaAB(IV) Rh(-) is suitable for absolutely everyone, since it contains nothing (0), however, such a question is never considered due to the rare occurrence of 4 blood groups with negative Rh.

How is the blood group determined?

Determination of the blood group according to the AB0 system can be done by taking a drop from the finger. By the way, every health worker with a diploma of higher or secondary medical education should be able to do this, regardless of the profile of their activity. As for other systems (Rh, HLA, Kell), a blood test for a group is taken from a vein and, following the method, the affiliation is determined. Such studies are already within the competence of a laboratory diagnostics doctor, and immunological typing of organs and tissues (HLA) generally requires special training.

A blood test per group is done using standard sera made in special laboratories and meeting certain requirements (specificity, titer, activity), or using tsoliklones obtained in the factory. Thus, the group affiliation of erythrocytes is determined ( direct method). In order to exclude an error and obtain complete confidence in the reliability of the results obtained, at blood transfusion stations or in laboratories of surgical and, especially, obstetric hospitals, the blood group is determined cross method where serum is used as the test sample, and specially selected standard erythrocytes act as a reagent. By the way, in newborns, it is very difficult to determine the group affiliation by the cross method, although α and β agglutinins are called natural antibodies (data from birth), they begin to be synthesized only from six months and accumulate by 6-8 years.

Blood group and character

Does the blood type affect the character and is it possible to predict in advance what can be expected in the future from a one-year-old rosy-cheeked toddler? Official medicine considers group affiliation in this perspective little or no attention to these issues. A person has a lot of genes, group systems too, so one can hardly expect the fulfillment of all the predictions of astrologers and determine the character of a person in advance. However, some coincidences cannot be ruled out, because some predictions do come true.

the prevalence of blood groups in the world and the characters attributed to them

So astrology says:

1. 1. Carriers of the first blood group are brave, strong, purposeful people. Leaders by nature, possessing indefatigable energy, they not only reach great heights themselves, but also carry others along, that is, they are wonderful organizers. At the same time, their character is not without negative traits: they can suddenly flare up and show aggression in a fit of anger.

1. Patient, balanced, calm people have the second blood type. slightly shy, empathetic and taking everything to heart. They are distinguished by homeliness, thriftiness, the desire for comfort and coziness, however, stubbornness, self-criticism and conservatism interfere in solving many professional and everyday tasks.
2. The third blood type involves the search for the unknown, a creative impulse, harmonious development, communication skills. With such a character, yes, move mountains, but that's bad luck - poor tolerance for routine and monotony does not allow this. The owners of group B (III) quickly change their mood, show inconstancy in their views, judgments, actions, dream a lot, which prevents the realization of the intended goal. Yes, and their goals are changing quickly ...
3. With regard to individuals with the fourth blood type, astrologers do not support the version of some psychiatrists who claim that among its owners there are most maniacs. People who study the stars agree that the 4th group has collected the best features of the previous ones, therefore it is distinguished by a particularly good character. Leaders, organizers, possessing enviable intuition and sociability, representatives of the AB (IV) group, at the same time, are indecisive, contradictory and peculiar, their mind is constantly fighting with their hearts, but which side will win is a big question mark.

Of course, the reader understands that all this is very approximate, because people are so different. Even identical twins show some kind of individuality, at least in character.

Nutrition and diet by blood type

The concept of a blood type diet owes its appearance to the American Peter D'Adamo, who at the end of the last century (1996) published a book with recommendations for proper nutrition, depending on the group affiliation according to the AB0 system. At the same time, this fashionable trend penetrated into Russia and was ranked among the alternative ones.

In the opinion of the vast majority of doctors with a medical education, this direction is anti-scientific and contradicts the prevailing ideas based on numerous studies. The author shares the view of official medicine, so the reader has the right to choose whom to believe.

• The assertion that at first all people had only the first group, its owners "hunters living in a cave", mandatory meat eaters having a healthy digestive tract can be safely questioned. Group substances A and B were identified in the preserved tissues of mummies (Egypt, America), whose age is more than 5000 years. Proponents of the concept "Eat right for your type" (the title of D'Adamo's book), do not indicate that the presence of 0(I) antigens is considered risk factors for diseases of the stomach and intestines(peptic ulcer), in addition, carriers of this group more often than others have problems with pressure ( ).
• The owners of the second group were declared clean by Mr. D'Adamo vegetarians. Given that this group affiliation in Europe is prevalent and in some areas reaches 70%, one can imagine the outcome of mass vegetarianism. Probably, mental hospitals will be overcrowded, because modern man is an established predator.

Unfortunately, the A (II) blood group diet does not draw the attention of those interested in the fact that people with this antigenic composition of erythrocytes make up the majority of the number of patients. , . They happen more often than others. So, maybe a person should work in this direction? Or at least bear in mind the risk of such problems?

Food for thought

An interesting question is when should a person switch to the recommended blood type diet? From birth? During puberty? In the golden years of youth? Or when old age knocks? Here the right to choose, we just want to remind you that children and adolescents should not be deprived of the necessary trace elements and vitamins, one should not be preferred and the other ignored.

Young people love something, something they don’t, but if a healthy person is ready, having just crossed the age of majority, to follow all the recommendations in nutrition in accordance with group affiliation, then this is his right. I just want to note that, in addition to the antigens of the AB0 system, there are other antigenic phenotypes that exist in parallel, but also contribute to the life of the human body. Should they be ignored or kept in mind? Then they also need to develop diets and it is not a fact that they will coincide with the current trends that promote healthy eating for certain categories of people who have one or another group affiliation. For example, the HLA leukocyte system is more than others associated with various diseases; it can be used to calculate in advance the hereditary predisposition to a particular pathology. So why not do just that, more real prevention immediately with the help of food?

Video: the secrets of human blood groups

Nowadays, future parents no longer have to guess the gender of the child. allow early. But the blood types of the parents can “tell” a lot about the future baby.

A certain combination of groups gives some guarantee that a boy or a girl will be born. There is a special table where the blood types of future mothers and fathers are compared. Depending on their combination, there is a certain probability of the appearance of a girl or a boy.

People can have one of four blood types and one of two Rh factors. Different parents will have a different set of these indicators.

• If the mother has the first blood group, and the father has the first or third, the probability of the birth of a female child is high.

The other two cases are more likely to give birth to a boy.

• Suppose the mother has a second blood type. Then she needs to find a partner with the same or a fourth group in order to give birth to a girl.
• With the first or third blood type of the father, they are most likely to become the parents of a son.
• Women with the third blood group can give birth to a girl when conceived by a man with the first group. In other cases, parents will receive a boy.

It turns out that the probability of women with such a blood type to give birth to a son is extremely high.

The same can be said about a pregnant woman with the fourth blood group, who can become the mother of a girl only in one case - if the man is a carrier of the blood of the second group.

Accordingly, other options involve the birth of a male baby.

But one cannot unequivocally treat such predictions, although they are justified from a scientific point of view. There is always a high probability of obtaining a completely different result.

Consideration should be given to the negative and positive Rh factors, which can affect the likelihood of having a baby of a certain gender.

• If both parents are Rh positive or Rh negative, a female baby is more likely to be born. If the rhesus are not the same, it is worth waiting for the appearance of a boy.

How to determine the sex of the child by the blood type of the parents?

You can consider determining the sex of a child by the blood type of the parents using a specific example. The woman is 34 years old and has two children from different partners.

Her blood type is second. From her first husband with the first group, she gave birth to a boy. In this situation, the results match the tabular data.

But the second civil husband has a third blood type. A similar combination should again lead to a similar result. A girl was born in the family.

Method validity

Even the most high-precision technique, except for ultrasound, does not give one hundred percent guarantees.

This method of determining the sex of a child by blood group raises many doubts, because the blood group does not change over the course of life (with rare exceptions), therefore, according to the above theory, only girls or boys will be born in the same couple.

In practice, everything looks different. Regardless of the blood type, many families have children of different sexes.

Parents often use a similar way of determining gender in a similar way and because of its simplicity. However, this method of determining the sex of a child does not always meet the expectations of parents.

However, this method allows you to plan the sex of the child. Only women with a negative Rh factor should be more careful, as there is a high probability of an Rh conflict.