Find out the child's blood type. Real examples of children inheriting blood types from their parents

It often happens that, having learned the blood type of their child, parents are at a loss. The mother is nervous: how did it happen that I have the third group, my husband has the first, and our daughter has the fourth? Thinking begins on the topic: what if the child was changed in the maternity hospital, but how is this possible if the child looks like his father and mother, and the blood types of the children and parents do not match? It turns out that such cases are also possible.

Story

From a historical point of view, people learned about the existence of groups only at the beginning of the 20th century thanks to the Austrian scientist Karl Landsteiner. He proved that if the blood of two people is mixed, there are two options for the development of events: the red blood cells of these people stick together or do not stick together. This allowed the scientist to conclude that everyone’s blood is different, and to talk about the compatibility or incompatibility of groups.

Karl Landsteiner greatly helped doctors with his discovery. Now it was only necessary to determine the compatibility of the donor and the patient and avoid tragic outcomes, especially when saving children, because sometimes the child’s blood type does not match the parents, and the latter cannot always become donors for their child. 20 years later, scientists learned that in a person’s receipt of a particular blood group important role The factor of inheritance plays, which depends on the laws of genetics, which work here strictly according to certain rules. The fact is that any inherited trait is determined by the genes of the mother and father, and different blood types in parents and children are the result of the interaction of these genes. The child's blood may be the same as that of the mother or father, or completely different.

How do groups differ?

Karl Landsteiner divided red blood cells into two categories depending on their composition (the presence of antigens in them). The first category contains antigens A, the second - antigens B. In addition, a separate group of red blood cells that does not contain antigens was defined as “0”. A little later, followers of the teachings of Karl Landsteiner discovered group 4, which contained antigens A and B.

Four groups

And to this day, according to the generally accepted standard classification, there are four groups according to the ABO system (“a, b, zero”). The first is 0, the second is A; III group B, fourth, respectively, AB. A and B are dominant genes, and 0 is recessive, which does not manifest itself in any way, and it is not possible to determine which people have this hidden gene. But if this gene combines with its own kind, then it can form the first group (00). In addition to the group, the Rh factor of the parents is directly involved in the formation of the child’s blood. The blood type of children and parents are certainly interconnected, and blood does not change over the course of a person's life.

"Plan"? It's possible!

Today you can recognize the group of an unborn baby based on the elementary laws of genetics. Each of us has two genes of the group, and the child inherits one gene from his mother and father.

From the inheritance table you can see how the blood type of children and parents correlate, and you can always independently determine the group of the future baby.

Group inheritance table

So, if the mother has the first group, then if the father has a similar situation, the child is guaranteed to inherit the first group. If dad is a carrier of the fourth group, then (with the mother’s first) the baby may equally have both... the second and third groups. Moreover, if the father has the second and third groups with the AA and BB genes, respectively, the child will have the second (A0) and third (B0) groups, respectively.

The blood type of children and parents often does not match. If the mother’s blood is of the second group with A0 genes, then if the father has the first group, there is a 50% probability that blood of either group I or group II (with A0 genes) will flow in the child’s veins. The second group of the father with the AO genes will provide the child with 25% of the possible presence of group I (the probability of the child having the second group will be 75%, respectively). At the same time, if the parents have blood type 3, the child will not be able to achieve type 2. If the father is a carrier of the fourth group, everything is much more complicated and incomprehensible. The probability of such a couple (mother is the second group, father is the fourth) having a child even with the third group is 25%, so sometimes there is a misunderstanding why the child has the third group, and the parents have the second and fourth.

Now let’s consider the question, what is the child’s blood group if the parents have 3? If the mother and father have the third group with B0 genes, then the probability of the child having the first group with 00 genes is 25%, the third group B0 is 50%, and, finally, the third BB is 25%.

If the mother has the third group with BB genes, then if the father has the group blood III with BB genes, a child will 100% inherit the third blood group with B0 genes. And if, with the same mother’s blood, the father’s blood of the third group has B0 genes, the child will inherit the third group with B0 or BB genes with a probability of 50%. That is, when the parents have group 3, the child cannot have group 2.

If the parents are carriers of the most rare group- fourth, then the child can become a carrier of any group except the first.

If both parents are carriers of the same groups with the same genes (AA or BB), then, accordingly, the child will have blood of the same group with the same genes.

Using the group inheritance table, you can determine the characteristics of the most important body fluid in a child. child by parents with most likely? Tests and advice from doctors will help with this. By the way, it is also possible here reverse stroke: if you know your group, you can determine possible options blood types of their parents.

Disease Prevention

Modern advances in medicine will tell you how to determine the blood type of a child based on its parents, but not only that. Diagnostic systems allow you to determine possible defects fetal development, and there is no point in talking about the importance of this information once again.

Donor for a child? Who can't become one?

The blood type of children and parents may match, and the parents will ideal donors blood for your child. If necessary, mom or dad can save their child. Or vice versa. You just need to remember that there is a certain category of people who cannot become donors. These are the people:

People with somatic diseases are also not eligible to be donors:

diseases of the central nervous system,
drug addicts and people with alcohol addiction,
persons with cardiovascular diseases,
people with respiratory diseases and other diseases of the sensory organs.

Rh factor

Now it is clear how a child’s blood type is formed from his parents - the table clearly shows us all the possible options. But we should not forget that another characteristic of blood is the Rh factor, which in a person can be either positive or negative and is determined by the presence of certain proteins in the blood.

People whose red cells have the D antigen are Rh positive. This is a characteristic of almost 85% of Europeans and 90% of blacks and Asians. In the absence of antigen D in the blood, a person acquires the status of an individual with a Rh-negative factor; such people are in the minority.

If the mother and father have negative Rhesus, the child is born only with negative Rh factor. If mom or dad is Rh positive, the baby can have any Rh. Contrary to popular belief, there is no complete incompatibility of the Rh factor during pregnancy. It is advisable that the mother and father's Rhesus be positive. A risk factor can occur when the mother has a negative Rh factor, the father has a positive Rh factor, and the child inherits the father's Rh factor. The mother's body will begin a “war” against the child’s blood by producing antibodies. But this can also be dealt with by following the advice of doctors.

Blood type incompatibility

It will appear if a woman has the first blood group (0), and a man has the fourth, second, third. If a woman is a carrier of the second blood group, then the risk exists if the man has the third or fourth. The third blood group of a woman “does not like” the second and fourth male groups.

Planning the gender of the child by blood type

Not only the blood type of a child is inherited from his parents. The table below demonstrates the possibility of planning the gender of the unborn child depending on the blood characteristics of the parents.

If the mother has the first group, and the father is a carrier of the first or third, then the child has high probability be born a girl, in other cases a woman has a greater chance of giving birth to a boy. To give birth to a girl, a mother who has the second group must select a partner with the second or fourth group, and if the mother has the third group, then the girl will most likely be born from contact with a male carrier of the first group. Let's say a pregnant woman is a carrier of the fourth group. If there is a desire to give birth to a girl, the father of the child must be a carrier of blood type II. This technique is not a 100% guarantee. Therefore, it is necessary to take into account the error when using it.

Inheritance of blood type and Rh factor by a child is carried out in accordance with genetic laws. During breastfeeding anti-Rhesus antibodies are destroyed in the child's stomach.

When planning a pregnancy or a pregnant woman contacts antenatal clinic for observation purposes, one of the main analyzes is determination of group and Rh factor blood future parents. This is necessary for many reasons, one of which is the prevention of complications associated with incompatibility of the blood of the mother and fetus.

What are blood groups

Blood Difference different people consists in various combinations of specific protein complexes or in the absence of some of them. The classification of blood groups is carried out in accordance with the main polysaccharide-amino acid complexes built into the erythrocyte membrane. They are antigens, that is, foreign to another organism. In response to them, ready-made antibodies are produced or already available that neutralize (destroy) the antigen.

If group antigens are located in erythrocytes, then antibodies are located in serum. When red blood cells with one blood group enter the plasma of a person with another group, they stick together and are destroyed by antibodies, which in mild cases manifests itself as so-called hemolytic (hemolysis - destruction) anemia or jaundice, and in severe cases - death of the body.

Normally, each person’s blood contains both antigens (agglutinogens) and antibodies (agglutinins), but not to their own agglutinogens. Conventionally, antigens are designated “A”, which correspond to antibodies “α” and “B” (antibodies - “β”). Thus, in accordance with this, four blood groups are determined, programmed in the genetic code of each person and designated by the AB0 system (0 - absence of antigens).

Inheritance of blood groups

According to the laws of genetics, the separation of chromosomes with the genetic set of one of the parents and their combination with the genetic set of the other in the offspring can give various combinations, on which the blood type of the fetus will depend. The probability of these combinations in the unborn child as a percentage is displayed in blood group inheritance table:

Blood groups mother and father	I gr. baby (%)	II gr. baby (%)	III gr. baby (%)	IV gr. baby (%)
I; I	100	0	0	0
I; II	50	50	0	0
I; III	50	0	50	0
I; IV	0	50	50	0
II; II	25	75	0	0
II; III	25	25	25	25
II; IV	0	50	25	25
III; III	25	0	75	0
III; IV	0	25	50	25
IV; IV	0	25	25	50

There are extremely rare exceptions when a child is determined to have a blood type that should not be there. This is called the Bombay phenomenon. It means the suppression of agglutinogens in the body of one of the parents, and his blood manifests itself as the properties of other groups. In this case, the suppressed gene is passed on to the child and manifests itself in him.

Due to the fact that antigens “A” and “B” are large molecules, they are not able to penetrate the placental barrier. At normal course pregnancy different groups blood of the mother and fetus do not show themselves in any way. During birth, some of the mother's antibodies and antigens, due to placental abruption, can penetrate into the baby's blood, as a result of which the child develops hemolytic jaundice in the first days after birth. More often it is unexpressed and passes quickly, but in severe cases it can be dangerous and require intensive treatment.

Rh factor inheritance

The Rh factor is a lipoprotein that is present on the membrane of red blood cells in 85% of people. Its presence is indicated by "Rh+". The absence of this factor in 15% of people is designated as “Rh-”. Inheritance is carried out according to the following principle:

If both parents have the Rh factor, the child also inherits the Rh factor of blood.
In cases where it is absent from the parents, it is (usually) absent from the child.
If one parent is Rh+ and the other is Rh negative, then the probability of inheritance is 50%.
There are cases of inheritance after several generations, when a child may be born with the absence of the Rh factor even if both parents have it.

If the mother's blood is Rh negative and the child inherits the Rh positive gene, then the mother's blood produces antibodies. Arises Rhesus conflict, as a result of which spontaneous abortions may occur and severe hemolytic disease of the newborn may develop. This usually happens when repeated births, since antibodies are produced slowly during the first birth. And although the blood circulation of the fetus and mother are separate, but with various infections And pathological course repeat pregnancy already existing antibodies easily penetrate into the fetal blood. To prevent their formation, a woman during her first birth is given anti-Rhesus immunoglobulin during the first three days.

Rhesus conflict does not arise:

in the absence of the Rh factor in both parents;
if the mother has Rh+ blood;The rhesus of the father and the fetus in this case does not matter;
If the mother has Rh- blood and the father has Rh+ blood, the child inherits the genes of Rh-negative blood.

There is still no consensus regarding feeding breast milk with Rhesus conflict. Antibodies disappear from breast milk during the first 2 weeks, after which feeding is possible. But it is now believed that they are destroyed in digestive tract child, despite his imperfections. Therefore, in maternity hospitals, breastfeeding is increasingly allowed from the first days.

What blood type will he inherit? future baby?, - this question worries many couples who are “waiting for a miracle.” To find out, we will tell you what blood type and Rh factor are, and whether it is possible to predict in advance what they will be like in a child.

What is blood?

Blood is nothing more than liquid tissue circulating within human body and supporting proper metabolism.

It consists of:

liquid part, that is, plasma and cellular elements;
erythrocytes and leukocytes;
platelets;
gas (nitrogen, oxygen and carbon dioxide);
from organic matter, which includes proteins, carbohydrates, fats and nitrogenous compounds.

What are the different blood types?

Blood type is nothing more than a difference in the structure of proteins. As an indicator, it cannot change under any circumstances. Therefore, blood group can be considered a constant value.

It was discovered by the scientist Karl Landsteiner at the dawn of the 19th century, who stood at the origins of the definition of the AVO system.

According to this system, blood is divided into 4 known groups:

I (0) - group in which antigens A and B are absent (molecules involved in the formation of immunological memory);
II (A) - blood with antigen A in its composition;
III (B) - blood with antigen B;
IV (AB) - this group contains two antigens, A and B.

The unique ABO (blood group) system changed scientists' understanding of the composition and nature of blood and, most importantly, helped to avoid errors during transfusion that occurred as a result of incompatibility of the patient's blood with the donor's.

Rh factor - what is it?

The Rh factor is a protein antigen found on the surface of red blood cells. Scientists first discovered it back in 1919 in monkeys and a little later confirmed the existence of the Rh factor in humans.

The Rh factor includes more than 40 antigens, which are designated using numbers and letters. The most common Rh antigens found in nature are D (85%), C (70%), E (30%) and E (80%).

According to statistics, 85% of Europeans become carriers of a positive Rh factor, and the remaining 15% - negative.

Rh factor mixing

Surely you have heard that when mixing the blood of parents with different Rh factors, a conflict often occurs. This happens if the mother is Rh negative and the father is Rh positive. In this case, the child’s health depends primarily on whose rhesus is “stronger.”

If the future baby decides to inherit the father’s blood, then the mother’s blood will “increase” the content of Rh antibodies every day. The problem is that, penetrating inside the fetus, they will destroy red blood cells, then the body itself, which ultimately can lead to hemolytic disease crumbs.

What are Mendel's laws?

The laws of Gregor Mendel, an Austrian biologist, which geneticists and doctors rely on, are nothing more than a clear description of the principles of the transmission of certain characteristics by inheritance.

They served as a strong basis for the subsequent emergence of the science of genetics, and it is on them that one should rely when predicting the blood type of a child.

Principles of inheritance of blood groups according to Mendel

According to the laws of Gregor Mendel, if parents have blood type 1, they will have children without antigens A and B.
If the parents of the unborn baby have blood groups 1 and 2, then the children will inherit them. The same applies to groups 1 and 3.
Blood group 4 is a chance to conceive children with group 2, 3 or 4, excluding the first.
The child’s blood type is not predicted in advance if his parents are carriers of groups 2 and 3.

The exception to these rules, which have not changed over the years, was “ bombay phenomenon». It's about about people whose phenotype contains A and B antigens, but for some reason they do not manifest themselves in any way. This situation It is found very rarely and most often among Hindus.

How is the Rh factor inherited?

The Rh factor is designated by the letters Rh. Being positive, it carries the prefix “plus”, and negative – the sign “minus”.

It is possible to guess its type with 100% accuracy only in the case when both parents are Rh negative; in all other cases, Rh will be different.

Inheritance system

The positive Rh factor, which is determined by the D gene, has different alleles in its structure: dominant (D) and recessive (d). In other words, a person with the Rh(+) type can carry both the DD and Dd genotypes. A person with Rh(-) Rhesus is a carrier of type dd.

Knowing this pattern of inheritance, it is quite possible to predict the future Rh factor in a child who has not yet been born. If the mother is negative with the dd genotype, and the father is positive (DD or Dd), then the baby can inherit any of the possible variants. This is clearly demonstrated by the following table:

Thus, if the father carries the DD type, the offspring of the couple will receive Rh-positive Rhesus, and if he has the Dd type, then this probability is reduced to 50%.

What else can a baby inherit?

Of course, parents are concerned not only with what blood type their child will have. They are also wildly curious whether the baby will inherit, for example, their eye or hair color.

Dominants and recessives

Such intriguing questions are answered by genetics, and this is done through its knowledge of two types of genes: dominant and recessive. The former always precede the latter and suppress them.

Overwhelming, dominant signs include such appearance features as blood type, freckles or dark skin, dimples, fluffy eyelashes, a hump on the nose, myopia or early graying.

So, for example, when brown eyes father and blue mother, the little one will be dark-eyed.

Traits that are inherited

The following can be inherited:

blood type and Rh factor (as we found out earlier);
skin color;
vision features (myopia or strabismus and other defects);
height (short or tall);
individual structural features of the arms and legs;
hearing characteristics (musical hearing, normal or deafness);
facial features (including freckles and dimples);
shape of the mouth, nose and ears;
hair color;
diseases (for example, diabetes mellitus and hemophilia).

But it is quite difficult to predict the baby’s character based on these signs. If only you try to determine the psychotype of personality to which the child will belong.

What about IQ?

Of course, a child can take not only blood type and external signs at their parents. However, the IQ value, which expectant mothers and fathers are also often worried about, does not greatly depend on heredity.

Oddly enough, for the development of a child’s intelligence and brain, a favorable family environment and early communication bring much greater benefit than heredity.

At the same time, according to experts, women who constantly exercise during pregnancy can give birth to a gifted child. It also stimulates the child's mental activity and breast-feeding(increases IQ by 6 units).

Health issue

As for diseases, everything has been known for a long time that, unfortunately, along with eye and hair color, a bunch of various diseases can be transmitted to us from our parents, including allergies, schizophrenia and even mental retardation.

But there is good news: today a person can receive his own individual genetic passport in order to find out about the dangers that threaten him. You can obtain it by contacting medical laboratory, engaged in DNA analysis and genetic research(and not just such standard tests as blood type and Rh factor).

Having done such an analysis, you will receive a personal “decoding” of the body’s characteristics, which will indicate a tendency to certain diseases, an attitude towards sports, a list of foods undesirable for consumption, and even a list climatic conditions, unfavorable for living.

Having learned about pregnancy, women strive 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 genetic laws, you can easily find out what blood type 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 type is nothing more than a feature of the structure of a protein. It does not undergo any changes, regardless of the circumstances. That's why this indicator considered as a constant value.

Its discovery was carried out in the 19th century scientist Karl Landsteiner, thanks to whom the AVO system was developed. According to this theory, 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 occurs;
IV (AB) - both antigens exist at once.

The presented ABO system contributed complete change scientific opinions regarding the nature and composition of blood fluid. In addition, mistakes that were previously made during transfusion and were manifested by incompatibility of the patient’s and donor’s blood were no longer allowed.

There are three groups 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 occur if one parent has M and the other has N.

Rh factor and its meaning

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

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

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

Mendel's laws

In his laws, Gregor Mendel clearly describes the pattern of inheritance of certain characteristics in a child from his parents. It is these principles that were taken as a strong basis for the creation of such a science as genetics. In addition, they must be considered first 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 group 1, 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;
the parents have the fourth - the child develops any one except the first.

The child’s blood group cannot be predicted from the parents’ blood group in a situation where mom and dad have 2 and 3.

How does a child inherit from parents?

All human genotypes are designated according to the following principle:

the first group is 00, that is, the baby’s first zero is transmitted from his mother, the other from his 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 indicator;
fourth - AB.

A child's inheritance of a blood type from its parents occurs according to generally accepted genetic laws. As a rule, 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 does Rh factor inheritance occur?

This indicator is also determined based on the presence of protein, which is usually 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 where 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.

Inheritance of the Rh factor is carried out by dominant trait. If two parents do not have the antigen that determines this indicator, then the child will also have a negative value. If one parent 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 Rh positive. It is also worth noting that in this case there is high probability a child receiving genes from a close relative who has a negative value for this indicator.

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

How to find out the blood type of your unborn baby

To determine whose blood type the child inherits, experts have developed a special table that allows each future parent to make predictions independently.

Upon careful study of the tabular results, the following interpretation is possible:

the blood of parents and children will be the same only if mom and dad have the first group;
if there is a second group 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 is the same as in the previous described cases.

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

Could there be 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. In the beginning this concept used exclusively for transfusion.

The blood fluid administered must not only match the group, but also have the same Rh factor. If this is not followed, conflict arises, which ultimately leads to fatal outcome. Such consequences are explained by the fact that when hit incompatible blood red blood cells are destroyed, which leads to a cessation of oxygen supply.

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

When pregnancy occurs, it is also possible that there may be a blood conflict between the child and the woman. Such situations are predicted in two cases:

The woman's blood is negative, and 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, her blood fluid will begin to produce antibodies.
If you expectant mother the first group, and for a man any other except 1. In this case, if the child does not also inherit the 1st group, a blood conflict cannot be ruled out.

If the first situation arises, everything may not end with the most favorable consequences. When inherited by a fetus positive rhesus immune system A pregnant woman will perceive the baby's red blood cells as foreign and strive to destroy them.

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

If this is your first pregnancy, then Rh conflict can be avoided. However, with each subsequent one the risks increase significantly. In such a situation, a woman should be constantly monitored by a specialist. She will also need to have blood tests done quite often for antibodies.

Immediately after the baby is born, his blood fluid group and its Rh factor are determined. If the value is positive, the mother is given anti-Rhesus immunoglobulin.

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

The second option does not pose a threat to the baby's life. In addition, it is diagnosed extremely rarely and does not have a complex process. The exception is hemolytic disease. If you suspect the development of this pathology, you will need to undergo regular tests.. In this case, for the birth to be successful, the most favorable time frame is considered to be 35-37 weeks.

Most experts argue that with a higher value of father's blood relative to mother's, the likelihood of having a healthy and strong child almost equals 100 percent.

Conflicts due to parental blood type incompatibility are not the same rare occurrence, but not as dangerous as with a discrepancy in the Rh factor.

If you conduct a timely examination, regularly visit a gynecologist and do not ignore the doctor’s instructions, this will increase the likelihood of a successful conception, pregnancy and birth of a baby.

Inheritance of blood groups 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 birth of the child.