What Rh factor will the child have a table. There are some general patterns of inheritance

There can be a great many situations when a child needs to determine his belonging to one or another blood group. The initial factor may be banal curiosity.

Doubts about future paternity by a potential dad are also not ruled out. And of course, there are extra moments when a child urgently needs a blood transfusion, and the parents have not yet had any relevant information in this regard.

There is another pretty good reason, thanks to such information, to know about the danger in advance. There are diseases associated with blood.

First of all, we are talking about hemolytic disease of the newborn (or Rhesus conflict). Knowing some points in advance, you can calculate the likelihood of this threat.

How to determine the blood type of a child

To date, the definition of this factor can occur in the following ways (of course, knowing all the data of the parents):

with the help of ABO system;
taking into account the Rh factor.

Some general information about genetics

To get information about a possible blood type in a child, knowing both of the parents, you just need to remember the course from school biology (exactly the moment when genetics took place). There is nothing complicated here: each of us always receives a pair of genes from both parents (one from mom and the other from dad).

The gene that appears (having all the sharp signs) will be dominant, and the second, which is not realized in any way in the body, is recessive (weak). At the same time, the fact is not ruled out that when a child combines both a dominant with a recessive one, two dominant ones, and there can also be both recessive ones.

To understand this process, a simple analogy with eye color is given:

If one of the parents has brown eyes, and the other has light eyes, then the dark-eyed father (or mother) will be the dominant link. The child will inherit both of these genes, but his eyes will be exactly brown.
A recessive gene is also able to appear, but only when it is paired with a similar one. Provided that each of the parents has bright eyes, then the child in the same case will also have bright eyes.

Another point that needs to be remembered when solving all genetic problems, we designate dominants in capital letters, and suppressed (recessive) signs in small letters. The same example with eyes will help us understand this:

Brown eyes in one of the parents indicate that it is customary to write his genotype with the letters AA or Aa.
Light is definitely a "weak" factor and the record in this case can be only in one variant aa.

And the options themselves can be as follows:

With “diluted” dominant Aa genes, it turns out that a child can be brown-eyed in half the cases (50%), and sky-blue eyes in half.
If the trait of one of the parents is unambiguously defined as AA, then even though the child will have a 100% Aa genotype, his eyes will be brown.

How will this knowledge help determine what you are looking for with blood? Approximately on a similar principle, but taking into account some more knowledge.

AB0 system to the rescue!

You should know that all groups will divide because of what specific protein is present in their red blood cells. The scientific name of such substances is agglutinins, each of them is usually denoted by the Latin letters A and B.

It is important to know the following:

If there are no such proteins in erythrocytes, then this is the first group.
The second will contain A-agglutinogens.
The third contains B-proteins.
Both components will meet in the fourth.

How can a blood type be inherited from his parents under such a system? The answer is not easy, because here three genes are responsible for the task:

Knowing the interaction of antigens is very important, for example, in the case of potential donation and blood transfusion.

Let's try to present the calculation using the example of each of the parents:

Let mom have a second blood type. In this case, its genotype can be represented by two variants IAIA or IAI0.
If the father has the fourth group, then his set is IAIB.
According to calculations, a child may have a fifty percent inheritance of variants of both groups, both father and mother (that is, both the second and the fourth).

pattern of inheritance

According to the law of genetics, which were formulated by Mendel, the child himself may have one of the following options:

If the mother and father have the first blood type, then the child will also have the same sign.
In the case when both parents have II blood type, the child has the first, so the second.
The third blood group indicates that the baby can be born, both without specific proteins in red blood cells, and with B-antigens (that is, groups I or III).
If there are such variants of parents as I II or I III, then it can be assumed that children will be born with one of them.
But there are also some “denials” here: if one of the parents has the fourth blood group, then they can’t have a baby with the first one. And vice versa.
But moms and dads with the second and third groups may well have children with any of the above signs.

Rh factor calculations

As for the Rh factor, it is also a protein. In the case when it is present, we can talk about it as positive. If there is no such substance according to the results of the analysis, then it is considered negative.

Calculations here can be built on the basis of the examples given for calculating the estimated eye color. It will be possible to designate a positive Rh as K, and a negative Rh as a small letter k. Recall that the gene responsible for the positive aspect will be dominant, while its opposite has a recessive trait. Then you can write it down like this Kk and KK will become variants of the human genotype with dominant traits, and kk, respectively, will belong to one of the parents with a negative Rh factor.

The calculation is simple: if the father has CC, then the future baby will have a positive Rh factor in one hundred percent of the case. This joyful moment turns out, as a rule, not very “pleasant” for a future mother who has a kk.

The fact is that this can turn into a conflict of antibodies of a baby that has not even been born yet. For this reason, a pregnant woman with a similar state of affairs is constantly taking blood tests, which helps to control the situation and take appropriate measures in time.

Rhesus (a protein located on the surface of red blood cells) is found in 75% of the population of our planet. The remaining fifteen percent do not have it.

It turns out this picture:

If the parents have both traits (both the dominant and the recessive allele), then there is still a fourth of the possibility that the baby will have a negative Rh. This will happen if two recessive genes "meet".
If at least one of the parents has the Rh antigen, there is a fifty percent chance that the child will be born both with it and without it.
But if in a pair both parents have a negative Rh factor, then the result of the birth of the crumbs will be the same.

Is it possible to establish paternity this way?

But it is impossible to establish paternity in this way (no matter what doubts would overwhelm a potential dad). Only special DNA analyzes can give such a result, but not the antigenic composition of the blood group.

Determination of the child's blood group is a study of the baby's blood sample, with the help of which the 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 analysis correctly?

Indications

A child will be assigned a blood type determination if:

He needs a blood transfusion.
The baby is scheduled for surgery.
The newborn is suspected of having hemolytic disease.

Determination of the blood group in a child is not planned and is carried out according to indications

A blood sample for analysis is taken from the child's vein. Most often, for such an analysis, a vein is taken from a vein in the elbow area, but if the child is very small, blood can also be taken from other veins.

How is it determined?

The blood type depends on the presence of certain proteins in the plasma and on red blood cells. Such proteins on red blood cells are called antigens (they can be A and B) - agglutinogens. Antibodies to them in the blood plasma are called agglutinins (they are alpha and beta). Their different combination causes 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. In our country, this is the first group.
BUT characterized by the presence of agglutinogen A and beta antibodies. In our country, it is called the second.
AT, in turn, it 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 grouping, 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.

Determination of the blood group is necessary during operations

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 Rh, antibodies are added to the blood sample and, after a few minutes, it is assessed whether cell agglutination has occurred.

Is it possible to find out the blood type without analysis?

Without blood sampling from a child, it is impossible to accurately determine the group and Rh. If there is a blood sample of the baby and two ready-made sera (groups A and B), then it can be determined by gluing red blood cells. It is only necessary to mix the baby's blood with each serum in turn, and after 3 minutes the gluing of the cells will be visible.

Do I need to prepare for the test?

No special preparation is needed for this analysis. 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.

In cases where the concept of a blood group is used, it means the group (according to the ABO system) and the Rh factor Rh. The first is determined by antigens located on erythrocytes (red blood cells). Antigens are specific structures on the surface of a cell. The second component is . This is a specific lipoprotein, which may or may not be present on the erythrocyte. Accordingly, it will be defined as positive or negative. In this article, we will figure out which blood type of children and parents will be a priority during pregnancy.

If the organism defines such a structure as foreign, it will react aggressively to it. It is this principle that must be taken into account in the procedures for transfusion of lymph. Often people have a false idea that the parents should match. There is Mendel's law, which allows you to predict the performance of future children, but these calculations will not be unambiguous.

As mentioned, the ABO blood system is defined by the location of certain antigens on the outer shell of the erythrocyte.

So, there are 4 blood groups in children and adults:

I (0) - no antigens A or B.
II (A) - only A is present.
III (B) - B is determined on the surface.
IV (AB) - both antigens - A and B are detected.

Inheritance of blood types

Parents often wonder if the blood type of parents and children can differ? Yes, this is possible. The fact is that the child occurs according to the law of genetics, where genes A and B are dominant, and O - recessive. The baby receives one gene from the mother and father. Most human genes have two copies.

In a simplified form, the human genotype can be described as follows:

- OO: the child will only inherit O.
- AA or AO.
- BB or BO: both one and the second trait can be equally inherited.
- AB: children can get A or B.

There is a special table of the blood group of children and parents, according to which it is clearly possible to guess which group and Rh factor of the blood the child will receive:

Parents' blood groups	Probable blood type of the child
I+I	I (100%)	-	-	-
I+II	I (50%)	II (50%)	-	-
I+III	I (50%)	-	III (50%)	-
I+IV	-	II (50%)	III (50%)	-
II+II	I (25%)	II (75%)	-	-
II+III	I (25%)	II (25%)	III (50%)	IV (25%)
II+IV	-	II (50%)	III (25%)	IV (25%)
III+III	I (25%)	-	III (75%)	-
III+IV	-	II (25%)	III (50%)	IV (25%)
IV+IV	-	II (25%)	III (25%)	IV (50%)

It is worth paying attention to a number of patterns in the inheritance of traits. So, the blood type of children and parents must match 100% if both parents have the first. In cases where parents have 1 and 2 or 1 and 3 groups, children can equally inherit any trait from one of the parents. If a partner has a 4th blood group, then in any case he cannot have a child with 1 type. The blood type of children and parents may not match even if one of the partners has group 2 and the other has group 3. With this option, any result is possible.

Things are much simpler with the inheritance of Rh: the D antigen is either present or absent. A positive Rh factor is dominant over a negative one. Accordingly, the following subgroups are possible: DD, Dd, dd, where D is a dominant gene and d is a recessive one. From the above, it is clear that the first two combinations will be positive, and only the last one will be negative.

In real life, this situation will look like this. If at least one parent has DD, then the child will inherit a positive Rh factor, if both owners of dd, then a negative one. In the event that the parents have Dd, there is a possibility of a child with any Rh.

There is a version that you can determine the parents. Of course, it is impossible to believe in such a calculation with great certainty.

The essence of calculating the blood type of the unborn child is reduced to the following principles:

A woman (1) and a man (1 or 3) are more likely to give birth to a girl, if a man has 2 and 4, then the likelihood of a boy will increase.
A woman (2) with a man (2 and 4) is likely to get a girl, and with a man (1 and 3) a boy.
Mother (3) and father (1) will give birth to a girl, with men of other groups there will be a son.
A woman (4) and a man (2) should expect a girl, with men of a different blood there will be a son.

It is worth noting that there is no scientific evidence for this theory. The method suggests that the unity of parents according to the state of blood rhesus (both negative and positive) speaks in favor of the appearance of a daughter, in other cases - a son.

conclusions

Currently, medicine makes it possible to determine which may appear in a child even before his birth. Of course, you should not completely trust the tables and independent research. Accuracy in determining the group and Rhesus of the unborn child can only be expected after a laboratory study.

What is really worth paying attention to is the fact that by parental blood it is possible with a high probability to establish predispositions to diseases of the future child.

One of the most important tasks in determining the category of blood is to reduce the possible risk of its transfusion. If alien genes enter the human body, an aggressive reaction can begin, the outcome of which is very sad. The same situation occurs with inappropriate rhesus. These circumstances are important to consider for pregnant women, especially those with a negative factor.

Do not forget about the possible mutations of genes that occur on earth to one degree or another. The fact is that earlier there was one blood type (1), the rest appeared later. But these factors are so rare that it is not worth dwelling on them in detail.

There are certain observations regarding the correspondence between the character of a person and his blood. From this, scientists have drawn conclusions about the predisposition to certain diseases. So, the first group, being the earliest on Earth, seems to be the most enduring; leaders are most often found among the people of this subgroup. These are pronounced meat lovers, but, unfortunately, they also have strong allergic reactions.

People of the second blood group are more patient and practical, they are most often vegetarians, including because of the sensitive gastrointestinal tract. Their immune systems are weak and they are often exposed to infectious diseases.

The third subgroup is represented by passionate natures, extreme people. They tolerate environmental changes better than others and have excellent immunity.

People of the fourth blood subgroup are the rarest, they are very sensual and see this world in their own way. They have a receptive nervous system and are often very altruistic.

It is up to parents to decide whether to trust such characteristics, whether to make predictions about the nature of their child, based on such observations. But using the achievements of modern medicine to improve the health of the unborn baby is never superfluous.

Since ancient times, blood has been considered a special, almost magical liquid. It was with her that the family relationship of children and adults was associated. So they said - "blood relationship", emphasizing the special strength of this connection. Today, through the blood group, they are trying to explain the character traits or nutritional habits of people. It is not surprising, therefore, that parents are interested in what kind of blood their child may have.

And it is equally important for doctors to know what blood type the parents of the unborn baby have. And this question is by no means idle. The course of pregnancy and the health of the mother and child, the likelihood of possible complications depend on how they are combined in parents and the unborn child. Some of these relationships have already become a medical axiom, while others are only talked about by practitioners.

Let's try to figure out how the blood types of children and parents are related: the inheritance table will help us with this.

Although this scarlet liquid has always been treated as something special and its connection with human life and health was understood, the real properties were not known for a long time. Only in 1900, the Austrian physician and scientist Karl Landsteiner, who studied blood serum, made a discovery that later brought him the Nobel Prize, and allowed mankind to use the transfusion of this life-giving fluid in treatment as a completely ordinary and familiar procedure.

The scientist took blood from himself and five of his employees, separated the red blood cells from the serum and mixed their samples with the serum of different people. Karl Landsteiner discovered that red blood cells behave differently in different combinations. In some cases, the red blood cells "stick together", forming clots, and in others they do not.

The interpretation of the results allowed him to initially distinguish three blood groups depending on the presence or absence of special particles, which he designated with the letters A and B, and the absence of 0. Later, his successors identified another group that contained both AB markers at once. Then they began to be denoted by Roman numerals. Today, the generally accepted classification by blood type looks like this.

This made it possible to determine the compatibility of blood and predict its behavior during transfusion from one donor to another.

Rh factor

Further study of the properties of blood revealed another factor that affects its compatibility. In 85% of people, a special lipoprotein was found located on the membranes of red blood cells, called the Rh factor. Those who have it are Rh positive (Rh+), those who do not have it are Rh negative (Rh-).

The presence or absence of this antigen does not affect human health in any way, but it is of great importance for the expectant mother. Since the child that develops and grows in it has its own blood group with the Rh factor, this can lead to a conflict with the maternal immune system, especially during repeated pregnancy.

That is why the parents of the unborn child are asked to be sure to take tests to establish the blood type and Rh factor. If the Rh factor of the father and mother is the same (both positive, or both negative), then there is no reason to worry. But if the Rhesus of future parents are different, then the onset and course of pregnancy requires closer attention from doctors.

The option is especially difficult when the mother is Rh negative and the father is Rh positive, since most often the baby inherits a positive Rh. This leads to the occurrence of a Rh conflict between the mother's body and the fetus, especially during repeated pregnancies.

Why the blood types of the child and parents do not match

How to recognize a group in children

To find out the possible blood group and Rh in children, you need to know exactly the characteristics of this vital moisture of the father and mother. The inheritance of these parameters is determined by the same laws of genetics as.

Table 1. Inheritance of the blood type of the child, depending on the blood types of the father and mother

Mom + Dad	Baby's Blood Type: Options (B%)
I+I	I (100%)	–	–	–
I+II	I (50%)	I (50%)	–	–
I+III	I (50%)	–	III (50%)	–
I+IV	–	II (50%)	III (50%)	–
II+II	I (25%)	II (75%)	–	–
II+III	I (25%)	II (25%)	III (25%)	IV (25%)
II+IV	–	II (50%)	III (25%)	IV (25%)
III+III	I (25%)	–	III (75%)	–
III+IV	–	I (25%)	III (50%)	IV (25%)
IV+IV	–	II (25%)	III (25%)	IV (50%)

Table 2. Inheritance of the blood group of the Rh system, possible in a child, depending on the blood groups of his parents

As we know, the baby can only get what his parents have. But sometimes parents can hide the presence of hidden recessive genes behind a dominant trait, and then a blonde child is suddenly born to two brunettes. But two blondes cannot have a brunette. So it is with the Rh factor.

A positive Rh factor is a dominant trait, so it is most often inherited. If both parents are Rh-negative, then their children will have a similar Rh- no variants. But in mixed couples, or even if both parents are Rh positive, but there are hidden Rh- genes, in this case there is a chance of having a baby with Rh-.

pattern of inheritance

As already noted, the blood type is determined by the presence or absence of agglutinogens A and B in its composition. The groups of parents influence what kind of blood the baby will have. The easiest way is if both parents have the first group. This means that neither A nor B is in the blood, therefore, their children can only have the same group. In all other cases, children have different options. It will be possible to know exactly about the blood group of the crumbs only after the analysis.

Human blood types. Tips for parents

There are 7.55 billion people on our planet. Despite the diversity of races, nationalities, skin colors, humanity has four blood types:

O - the first I;
A - second II;
B - third III;
AB - fourth IV.

Their discovery took place in 1900. The Viennese biochemist Landsteiner, while conducting experiments, noticed that the erythrocytes of blood samples from laboratory employees in some cases do not mix, but stick together and settle to the bottom. This is how the classification into main groups appeared, which became the basis of modern hematology - the science of blood.

This discovery saved many lives during World War I. Prior to this, blood transfusions were carried out without any system. The one who got the blood that matched the group had a chance of survival. Now it is determined in a newborn in a maternity hospital. But, knowing the genetic laws, it is possible even before birth to calculate what blood type the child will have.

Human blood is a liquid medium consisting of plasma and cells - leukocytes, platelets and erythrocytes.

It is the red blood cells that give the blood its scarlet color. Their main function is to carry out gas exchange in the cells of the body. On the surface of the membrane of red blood cells are antigen proteins A or B. Their absence is indicated by O, and the joint - AB. Hence the designation of each of the four groups.

A person has his own blood type from birth, it is formed in the womb from the moment of conception. It is inherited according to a certain law, discovered by the geneticist Gregor Mendel. Remains constant throughout life.

The belonging to any of the groups is determined by exposure to a blood sample with special substances. According to the type of reaction, a designation is assigned - O, A, B or AB. Usually this information is entered into a medical record. It is customary for the military to indicate this indicator on the uniform.

30% of the world's population has the first group, 40% - the second, 20% - the third. The smallest is the fourth. Only every tenth person has it.

Determining the blood type is important for emergency transfusions, as well as for surgical interventions. Another characteristic necessary for medical manipulations is the Rh factor.

What is rhesus

It was discovered in 1940 by the same scientist, Landsteiner, in collaboration with the American biologist A. Wiener. Examining the erythrocytes of rhesus monkeys, they found that they contain another antigen - D. Its presence was designated Rh +. In the course of further experiments, it turned out that some people (approximately 15%) do not have this antigen. Such a sign began to be designated Rh-.

Rhesus is transmitted from parents to children, positive Rh is dominant. Remains unchanged throughout life, does not affect health. Determined in the laboratory.

How is blood type inherited?

The transmission of antigens occurs by inheritance, when the child's blood type and Rhesus are formed.

The human genotype consists of two parts - one he receives from his mother, the other from his father. The gene of the first blood group is recessive, that is, it is suppressed by the rest. In a pair, he does not manifest himself, but is present. You can schematically write down the possible options:

00 - the first group;
0A or AA - the second;
0V or BB - the third;
AB is the fourth.

Each of the parents subsequently carries their own set of genes that determine the characteristics of their blood.

At conception, one half of the father's gene is paired with the other half of the mother's gene. The offspring receives its unique biological material. What blood type the child will have can be calculated from table No. 1:

If a woman and her partner have 1 group, their baby will have the same at birth.

The largest number of options - four - can be in a child born to parents with 2 and 3 blood groups.

With a combination of 1 with 2 or 3 groups, the child will receive this indicator from the mother or father.

It happens that the blood type of the child does not match the parent. This happens if one of them has 4 and the other has 1 group.

How is the Rh factor inherited?

The presence or absence of Rhesus is transmitted according to the law of dominance. With a positive Rh in the parents, the child will definitely inherit it. If both parents have no D-antigen, then the baby will have a negative Rh.

A person inherits a trait from each of the parents, but even with a positive Rh, he can be a carrier of a recessive negative gene. Existing combinations can be written with a combination of letters:

DD and Dd are positive;
dd is negative.

The transfer of Rhesus from parents to baby in table number 2 looks like this:

In a father and mother who are both Rh-positive, but who are carriers of hereditary Rh-, the unborn child can inherit Rh-negative with a probability of 25%.

An example of the inheritance of blood type and Rh factor

A woman with blood with indicators A (II) and Rh-, and a man with B (III) and Rh +, should have a baby. How to find out the blood type of a child and his Rh?

In table No. 1, in the column at the intersection of the corresponding columns, it is indicated that the child has the probability of inheriting any group.

Table No. 2 contains information that the probability of having a baby with a positive or negative Rh is estimated as equal, 50 to 50 percent.

Next example. A man with A (II) and a woman with O (I) decided to have a baby. Both are Rhesus positive. What blood type and Rh does the unborn child inherit from the parents?

According to the tables, we determine that the possible options are O (I) or A (II). Rhesus can be negative with a probability of 25%. Dad and mom can be carriers of the Rh- gene, it will manifest itself when transferring traits to the heir. When two recessive genes are combined, they become dominant.

This is possible if both parental lines had Rh-negative ancestors. Carriership was inherited, without showing itself in any way.

Negative Rh factor in pregnant women

A pregnant woman is carrying a child whose D-antigen may not match her own. When they talk about Rh conflict, they mean negative Rh in the mother and positive in the fetus. In other cases, there are no complications during pregnancy associated with this indicator.

Rhesus conflict is most likely in the second and subsequent women if her partner is Rh-positive. In 75 cases out of 100, the child inherits the Rh father.

A complication of Rh-conflict can be fetal hemolytic disease, late miscarriage, intrauterine hypoxia.

To avoid dangerous consequences, the pregnant woman is put on a special account. The content of immunoglobulin M and G in her blood is regularly monitored. Control measures are carried out - ultrasound, cordocentesis, amniocentesis. This allows you to take action in time if something begins to threaten the child.

There is no need to panic ahead of time. Rh-conflict occurs no more often than in 10% of cases during the first pregnancy. To avoid it during repeated pregnancies, a woman receives a special drug - anti-Rhesus immunoglobulin - within three days after childbirth.

Even if the drug has not been administered, vaccination can be carried out at the next pregnancy. It will significantly reduce the risk of Rh-conflict between the mother and the unborn baby.

There are still some factors of incompatibility of the blood of the parents that need to be clarified before conceiving a child. If they are serious enough, and the spouses really want children, you need to prepare for his birth in advance.

After the fertilization of the egg by the sperm, conception occurs - the formation of a new organism that has maternal and paternal characteristics. Each of the parents endows the offspring with 23 chromosomes, where all hereditary traits are encoded. They can be dominant, that is, overwhelming, and recessive, not prevailing. genotype in advance. Genetics can give an answer, with some degree of probability, which eyes, nose or lips the baby will inherit.

Conclusion

The blood type of a child is determined according to the laws of genetic inheritance. Parents can find out in advance using tables and calculators. But one hundred percent certainty exists only in cases where only one option is possible.