With what Rhesus can not get pregnant. Can it be that partners do not fit together: blood types and their compatibility when conceiving a child

12.09.2019

Questions of blood compatibility are quite a relevant topic of modern medicine. It gained its significance with the development of genetics and immunohistochemistry, which were able to substantiate absolutely paradoxical cases in medical practice. After all, sometimes things happen that defy absolutely no logical justification. This happens especially often when determining the compatibility of blood for conception when planning a family, pregnancy or the need for a transfusion. All these paradoxes once again confirm that there is nothing absolute in medicine, since a lot of things are still covered with secrets that humanity has to reveal. But even what is already known deserves close attention.

The basic concept of the Rh factor

The specificity of any organism is determined by a set of proteins or antigens that are part of any tissue. In relation to blood and its erythrocytes, these are their surface antigenic complexes. One of them is the Rh factor or Rh antigen. Depending on its presence, all people are divided into Rh-positive (carriers of the antigen) and Rh-negative (people who do not have the Rh antigen). All life situations that are associated with the need to mix the blood of different people are determined by the ability of the blood not to disrupt its structure after such a procedure. In many respects it depends on Rh compatibility.

Important to remember! Compatible blood according to the Rh factor system is that which will be perceived by the body as its own. This means that only blood that is identical in terms of the Rh factor can be so!

Blood compatibility for conception

Family planning is a very correct direction of obstetrics, which has significantly reduced the number of complicated or unwanted pregnancies. This was manifested by the birth of a smaller number of seriously ill children. Today, every woman knows about all the threats that can await her and her child in the case of a cold-blooded attitude to some details of proper family planning. One of these details is the compatibility of the blood of sexual partners.

In fact, this topic is slightly misrepresented in the media. Everyone who misunderstood it interprets everything in his own way, spreading unreliable and, most importantly, untrue information. In this regard, it is worth considering the issues of immunological compatibility of spouses and compatibility of the blood of spouses at conception, which were mixed with each other and are discussed as one and the same problem. This sows panic and makes people look for a non-existent truth. Therefore, it is important to understand that:

The compatibility of spouses when a woman is unable to become pregnant does not depend on the compatibility of blood groups or the Rh factor, but on the immunological compatibility of a woman and a man. This means that antibodies are produced for the components of a particular male sperm in the body of a woman who simply does not perceive it. The group and the Rh factor have nothing to do with it at all;
An Rh-negative mother can give birth to a child with Rh-positive blood. This can only affect the course of pregnancy and the condition of the fetus, but cannot be regarded as Rh factor incompatibility for conceiving a child;
A couple with different Rh factors can quite easily have healthy children. It is not necessary to destroy the relationship due to the fact that the Rhesus of the mother and fetus can potentially be incompatible. But you should definitely follow the recommendations in the framework of family planning, which will be pointed out by specialists. Some of these recommendations are given in the next section.

It is impossible to reliably predict the development of Rh-conflict pregnancy

Blood compatibility during pregnancy

If a married couple has decided on pregnancy, they must follow this process from the planning stage to the birth of a child. With regard to the potential for Rhesus conflict during pregnancy, the following should be alert:

Married couples in which the woman is Rh-negative and the man is Rh-positive. The maximum probability of a conflict pregnancy is 50% if the partner is homozygous (each of the chromosomes of one pair encodes the Rh antigen) and 25% if it is heterozygous (Rhesus is encoded by only one chromosome from the pair);
Spouses whose blood mixing is potentially capable of ending with an Rh-conflict pregnancy, with previous pregnancies and childbirth. Their favorable outcome does not mean anything. On the contrary, the likelihood of developing maternal and fetal blood incompatibility increases with each subsequent pregnancy.

Compatibility of blood groups and the table is compatible with the Rh factor with possible options for its inheritance by the child.

Rh factor of the mother	Father's Rh factor	The probability of Rh belonging to the child	The likelihood of Rh-conflict pregnancy
Positive	Positive	If the parents are homozygous - 100% positive; If parents are heterozygous - 50% positive; If one of the spouses is homozygous, and the second is heterozygous - 75% positive.
Positive	Negative	If the partner is Rh positive or the partner is homozygous for Rh - 50% positive; If heterozygous - 25% positive.	The probability of a conflict developing does not exceed 50%
Negative	Positive
Negative	Negative	The blood of the child in 100% of cases will be Rh-negative.	Conflict pregnancy does not occur

Note: A homozygous is a person who contains identical genes on similar chromosomes. They, getting into the composition of the chromosome set of the fetus, will unambiguously encode the synthesis of the Rh factor. A heterozygote contains such a gene only in one of the chromosomes, which significantly reduces the risk of its inheritance.

Important to remember!!!

The blood of an Rh-positive mother is compatible with any fetal blood;
The probability of a conflict in the Rh system is possible only in mothers with Rh-negative blood and does not exceed 50%;
The inheritance of the Rh factor by a child depends not only on the actual Rh of the parents, but also on the set of genes that did not manifest themselves, but were inherited by the child.

Donor compatibility

Despite all modern concepts and the desire of physicians to avoid transfusion of blood and its components, in practice this is not feasible. After all, thousands of situations arise every day when only these drugs can save a person's life. One of the main postulates in this regard is the determination of the compatibility of the blood of the donor and the recipient. Indeed, otherwise, inappropriate blood will not only not help, but will also cause the death of the patient.

With regard to donor compatibility, only erythrocyte preparations (erythrocyte mass and washed erythrocytes) are considered. Before direct blood transfusion, blood group compatibility and Rh compatibility are determined. In the classic version, only blood with an identical Rh factor and group is considered absolutely compatible. But this rule does not always work in practice. In some situations where an emergency blood transfusion is required in a matter of minutes, there is no time to determine compatibility. The only salvation is the transfusion of whole blood or red blood cells on the principle of hypothetical compatibility. Its options are given in the form of a table.

Donor Recipient	First	Second	Third	Fourth
First 0(I)	Compatible	Incompatible	Incompatible	Incompatible
Second A (II)	Compatible	Compatible	Incompatible	Incompatible
Third B(III)	Compatible	Incompatible	Compatible	Incompatible
Fourth AB(IV)	Compatible	Compatible	Compatible	Compatible

The following practical conclusions can be drawn from the table:

People with the first blood group are, but they themselves can only become recipients of the blood of the first group;
People with are a universal recipient, although they themselves can only be donors for people with the fourth group;
Donor compatibility is possible only if the donor's erythrocytes do not contain the appropriate antibodies that will cause their destruction after transfusion.

Important to remember! Rh factor compatibility of blood is determined only in two ways, regardless of group affiliation: people with Rh-negative blood can only be transfused with Rh-negative blood. People with Rh-positive blood can become recipients of blood from both Rh-positive and Rh-negative donors!

Blood group compatibility is a problem that deserves attention from both scientists and the average person. This topic is touched upon in various life circumstances: family planning, transfusion of biological fluid, bearing a child. Deciding which blood type is appropriate plays an important role in donor practice. Without an appropriate test, the examination during pregnancy is incomplete. Therefore, you should know which blood groups are incompatible, when blood transfusion can be performed, and in which blood transfusion is contraindicated.

A little about the main

The blood group test is very important for a person. It allows you to be prepared for different life situations: donation, the development of genetic pathology, bearing a child. Of great importance is the compatibility of blood for conception. In its absence, the husband and wife, the process of pregnancy is accompanied by serious difficulties.

The emergence of different types of people is due to the expansion of the zone of human habitation, a change in the diet. The daily menu began to include meat and dairy products. This was reflected in the qualitative composition of the biological fluid.

Changed the parameters of its main elements.

Classification by human blood groups is represented by the AB0 system. It is based on two metrics:

the presence in erythrocytes of special substances of a protein nature - antigens A and B;
the presence in the plasma of antibodies - agglutinins α and β.

According to the AB0 system, four types are distinguished:

The question of which blood groups are compatible and which are not should be of interest even before the onset of a problem situation. The test can be done in any laboratory fairly quickly. Knowing your blood type, its compatibility with others and a timely examination for this will significantly save precious time if necessary.

The concept of Rh compatibility

The Rh factor is an antigenic structure located on the surface of red cells. Depending on its presence, another classification is distinguished:

having an antigen (Rh positive);
people with its absence (Rh negative).

The Rh factor for transfusion or conception compatibility also plays an important role. When combining two different types of biological fluid, serious consequences for humans can develop. For example, a 2 positive cannot be transfused to a person with a second negative. Therefore, determining the presence of an antigenic complex is one of the important medical procedures.

Conception and Compatibility

Family planning has become one of the directions of modern obstetrics. A thorough examination of both spouses, preparation for the appearance of children - had a beneficial effect on reducing the birth rate of sick children, reducing the number of infant mortality. Therefore, both a woman and a man should be aware of what the Rh factor is and how it can affect the process of conception, whether the compatibility of blood groups plays a role in conceiving a child, why incompatibility is possible in the presence of one group.

In doing so, keep in mind the following points:

the compatibility of a man and a woman is manifested in an immunological combination, in the absence of which the female body of the spouse produces antibodies to sperm components (compatibility by blood type and Rh factor does not matter here);
a family where the husband and wife have different poles of the Rh factor can have healthy children, but subject to all the recommendations of a specialist;
Rh incompatibility between mother and fetus affects the pregnancy process, but not the possibility of conception.

Carrying a child and compatibility

Pregnancy is always a difficult process. This is due to various factors. Among them, the occurrence of a Rh-conflict situation is of great importance. It occurs when the mother has a negative group, and the unborn child has a positive group. In this case, the female body reacts to the fetus as if it were a foreign body, producing antibodies. The latter, penetrating the placenta, have a detrimental effect on the red blood cells of the child, causing the corresponding complications of pregnancy.

A conflict pregnancy can result in:

miscarriage;
increased work of the liver and spleen of the fetus;
the development of anemia as a result of excessive activity of the liver.

In order to avoid the negative consequences of the development of a conflict pregnancy, it is necessary to take a test on time, which allows you to identify the compatibility of blood types in spouses at conception. In the absence of a timely examination of a married couple, the manifestation of the following pathologies in a newborn child is possible:

anemic condition;
development of dropsy;
development of jaundice;
problems with mental development.

In order for the pregnancy period to proceed calmly and without complications for the mother and her baby, it is necessary to register in a medical institution on time. Thanks to modern diagnostic procedures, the process of bearing a child is always under the control of specialists. This will allow you to take appropriate action:

take a biopsy of the chorion - the procedure is necessary to determine the pole of the Rh factor in the fetus;
administer immunoglobulin to a woman on time;
conduct timely stimulation of artificial labor;
carrying out the procedure of cordocentesis (puncture of the vessels of the umbilical cord) if necessary.

Compatibility in donor practice

The effectiveness of transfusions in donation is largely determined by the compatibility of blood groups during transfusion. Knowing the features associated with this allows you to avoid medical errors.

After all, despite significant advances in the field of medicine, blood transfusion is still an important procedure that has saved the lives of many people.

Before carrying out any blood transfusion, it is imperative to check whether the donor's biological fluid is suitable for the recipient, that is, the one to whom it will be transfused.

There is the following table for this:

	Recipient	Donor
Group 1	I, II, III, IV	I
Blood type 2	II, IV	I, II
Blood type 3	III, IV	I, III
Blood type 4	IV	I, II, III, IV

Analyzing the tabular data, we can say that:

Type 1 is universal, it can be transfused to any person (however, the body of donors with this type is able to accept biological fluid only of its own type);
people with type 4 blood can be transfused with other types of blood (but they can only become donors to those who have the fourth group);
group compatibility during transfusion is possible only when there are no antibodies in the donor erythrocytes that can cause their destruction after transfusion (in other cases, the biological fluid is unsuitable);
the donor is compatible only with the second and fourth blood groups of the person who is being transfused;
the combination of the third group of the donor is possible with the third and the first group of the recipient.

It is important to remember that blood compatibility, based on the pole of the Rh factor, is possible only in the following cases:

the donor's Rh negative type is compatible with the recipient's Rh negative type (for example, 1 positive blood is not transfused into first negative recipients);
the Rh positive type of recipient is compatible with the blood of donors with different Rh factors, while the compatibility of blood groups is in no way related to the compatibility of the Rh factor.

The situation of compatibility of blood types is relevant in connection with the consequences that it entails. At all stages of pregnancy, its control is necessary for the birth of healthy children. Blood transfusion is an important medical procedure, without which it is impossible to carry out many surgical interventions. Therefore, the question of which blood types are compatible is most acute. Timely examination, knowledge of the necessary parameters of your condition will allow you to control your health, preventing the development of serious illnesses.

In contact with

Pregnancy planning includes a set of measures aimed at optimizing the conditions for conception and the birth of healthy offspring. It is desirable for future parents to examine the body, give up bad habits, lead a correct lifestyle, and prepare yourself emotionally.

Doctors recommend pre-determining the blood group and Rh factor. The most important nuance for conceiving a child in marriage is to check the compatibility of parents by blood group and Rh factor according to the tables that are presented in our article.

Story

Human blood is characterized by one of four groups, distinguished by a set of specific proteins within the red blood cells. Usually, proteins (another name for antigens or agglutinogens) are denoted by the letters A and B. The erythrocytes of the first blood group do not contain antigens, the bodies of the second include only protein A, the third - B, the fourth - both of the above proteins.

The age of the first antigenic phenotype is estimated at 60-40 thousand years.

It is most common in areas of South and Central America., which is due to minimal migration and the absence of mixed marriages between local residents and representatives of other nations.

The second appeared much later in Asia, approximately 25-15 thousand years ago, a large proportion of carriers live in Europe and Japan. It is interesting that the number of people of groups I and II prevails and makes up 80% of the population.

The emergence of the third group is regarded by some researchers as the result of evolution that has changed the human immune system, others as the result of a mutation.

The emergence of the fourth group is a mystery to scientists. According to the investigations of the substance on the Shroud of Turin, in which the body of Jesus Christ was wrapped, he was the owner of this youngest group.

A child inherits a set of proteins from parents, based on the laws of genetics. To determine the possible combination of antigens of the future baby, we find probable inheritance options at the intersection of the columns of the mother and father groups.

Inheritance during pregnancy

Table of inheritance of a blood group in a child.

In this way, mother and father with the second and third groups give life to children of any combination of agglutinogens with the same probability. In a couple with the first group, children are born whose red blood cells lack proteins. The carrier of the fourth group will never give birth to the offspring of the first.

Genetics, like other sciences, is not without exceptions. In a small percentage of people, red blood cells include the A and B antigens that do not manifest themselves.

As a result, the infant inherits a different set of agglutinogens than is possible. The paradox is called the "Bombay phenomenon" and is determined by one in 10 million people.

The circulatory system of the baby is formed in the womb. Antigens appear in cells in the early stages of pregnancy (2-3 months).

When the baby inherits from the father a protein that is absent in the mother's blood, there are cases of formation in a woman of antibodies to a protein foreign to her. This process is called blood type conflict or immunological conflict, in which case their compatibility is in question.

Incompatibility develops in the following cases:

in a woman I group, in a man II, III, IV;
in a woman II, in a man III, IV;
in a woman III, in a man II or IV.

The alignment is especially dangerous when a woman of the first group bears a baby with II or III. This situation often causes complications.

Fortunately, most incompatibilities are easy. and does not require intensive care. Incompatibility during re-conception does not entail more unpleasant consequences.

Compatibility table for conception by blood type of husband and wife.

Sometimes the female immune system begins to produce anti-sperm antibodies that kill sperm. Then an absolutely healthy couple faces problems of conception.

Therefore, proper pregnancy planning involves testing for antisperm antibodies.

Rh father and mother

In addition to the group, blood is characterized by the presence of another antigen in erythrocytes - the Rh factor.

Most people on the planet are carriers of the Rh factor (Rh) They are called Rh-positive.

Only 15 percent of the population does not contain Rh in red cells, they are Rh-negative.

The inheritance of the antigenic phenotype and the Rh factor occur independently of each other.

It is possible to say exactly which Rh factor a child will receive only when both parents have Rh negative.

In other situations, it is impossible to predict Rhesus, it can be anything.

Table for determining the rhesus of a child.

Some cases are characterized by immunological incompatibility for the Rh factor between the mother and the fetus. The conflict manifests itself in a small percentage of the fair sex. with a negative Rh, if the baby inherited the positive Rh of the father.

The mother's body produces antibodies that attack the baby's red blood cells through the placenta. Unfortunately, the placental barrier provides 100% protection only in the ideal course of pregnancy, which is very rare. Attacks on a still unformed being destroy the liver, heart, kidneys.

Pregnancy complicated by Rhesus conflict often ends in miscarriage. When the baby manages to survive, dropsy, jaundice, anemia, and mental health problems are likely.

And how does a Leo man behave in love and relationships? We will talk about the bright representatives of the “fiery” sign in this article:.

How to behave in case of Rhesus conflict

The expectant mother must know the blood type and Rh. Planning for conception first of all, it is worth passing the appropriate tests(to determine the blood type and Rh factor), because the compatibility of spouses is important for the birth of healthy children, but not required.

Note that it is possible to bear and give birth to a healthy, strong child even with an immune conflict. The girl needs to be under the supervision of a doctor. If antibodies are detected, treatment is prescribed.

During the bearing of the firstborn, such a conflict appears less frequently, which is due to a number of biological reasons. Risk factors for Rh - negative women are previous miscarriages, abortions,.

Antibodies tend to accumulate this means that the destruction of red blood cells during subsequent pregnancies will begin earlier, respectively, will cause more severe consequences.

The most serious complication of the above situation is hemolytic disease of the newborn. It is distributed in three forms:

icteric - yellowing of the skin;
anemic - jaundice, no edema;
edematous - accompanied by general edema, jaundice.

Diagnosis of maternal and fetal incompatibility start with determining the Rh of the fetus. In the presence of Rh-positive blood in the father and Rh-negative in the mother, pregnant women have at least a monthly blood test for antibodies.

Bearing occurs without discomfort, only slight weakness is possible.

Symptoms of incompatibility are detected only by ultrasound examination. When there are more antibodies, and ultrasound shows abnormalities in the development of the fetus do intrauterine blood transfusions.

In the event of a threat to the life of the pregnant woman and the fetus, a decision is made on artificial childbirth.

The birth of a new life is a great happiness, which is sometimes overshadowed by a doctor's diagnosis after potential parents have been tested. Pregnancy planning is the most important stage, but not a panacea for unpleasant surprises.

In this video, there is some more information about why it is so important for parents to take tests to determine the blood type and Rh factor when registering during pregnancy:

Even if you got pregnant out of the plan, don't worry. It should be remembered that love conquers everything, and a timely appeal to an experienced specialist and an examination will significantly increase the chance of a favorable development of the baby.

There are four blood groups according to the AB0 system. This is due to the presence or absence of antigens in it. The antigens found in erythrocytes (red cells) are called agglutinogens.

Reference! Agglutinogen is a protein compound that identifies foreign substances (for a specific organism) and interacts with antibodies. Plasma antigens (the liquid part of the blood) are agglutinins.

Agglutinin is a protein substance that performs the reaction of agglutination of blood cells, bacteria and other antigens, is involved in the immune response. Agglutinogens are of two types and are signed with capital letters A and B.

Group I does not contain agglutinogens. Denoted 0 or "zero";
II Group designated A because it contains this type of agglutinogen;
III Group includes agglutinogen B, and has the same name;
IV Group contains both agglutinogens and is signed as AB.

Agglutinins are also of two types. Denoted by small letters alpha (a) and beta (b).

Group I includes both agglutinins - a and b;
II Group contains agglutinin b;
III Group carries agglutinin a;
IV Group does not contain agglutinins.

The combination of erythrocyte and plasma antigens distinguishes different blood types, and we will consider their effect on conception further.

Do their combinations affect the conception of a child and pregnancy?

Representatives of the beautiful half of humanity often ask questions: “What blood types are compatible and suitable for each other, with what type is the probability of conceiving a child higher, is it possible to get pregnant if they have the same blood as their husband, is this possible when one spouse has the first or third positive , and the second has the second or fourth negative, is there a group with which it is difficult to get pregnant when a woman cannot terminate a pregnancy?

You can get pregnant and have children with any blood type. Different combinations of blood types of parents do not affect their reproductive system, partner compatibility, conception and pregnancy.

The likelihood of conception is determined by many factors, here are some of them:

The state of health of the spouses.
Partner fertility.
The phase of a woman's menstrual cycle when unprotected intercourse took place.

Sexually transmitted infections (STIs), some systemic diseases, as well as bad habits adversely affect the reproductive system of both partners. Fertility in relation to a man determines his ability to fertilize an egg. It comes from the moment the production of mobile and live spermatozoa begins.

Female fertility (the ability to conceive and bear a child) begins from the moment menstruation is established. However optimal reproductive age - 22-35 years when a girl is psychologically ready for motherhood and is able to endure the hormonal changes in the body associated with pregnancy.

Reference! Ovulation (the release of an egg from the ovary) occurs only once a month. Its viability is 12-24 hours. The viability of spermatozoa in a woman's body is 3-5 days, rarely up to a week. This time will be the most successful for conceiving a child.

Is there any incompatibility between the parents?

There is a myth that the development of incompatibility during conception is possible in cases where one parent has agglutinogens in the blood, and the other has the agglutinins corresponding to them, for example, A and a or B and b.

These indicators are important to take into account when transfusing blood, in order to avoid its intravascular coagulation. On the probability of conceiving a child, intrauterine development of the fetus, as well as on the course of pregnancy, these factors for any blood type do not affect in any way.

Termination of pregnancy and Rh factor

When terminating a pregnancy, it is important to consider not the group, but the Rh affiliation.

The Rh factor is an antigen of a protein nature. If it is present, it indicates a positive Rh factor, a negative Rh indicates its absence. Abortion always poses a certain risk to the female body. Especially if a woman has a negative Rh, she may subsequently remain infertile, the likelihood of an Rh conflict or the birth of a dead child increases.

If the pregnant woman has a negative Rh, and the child is positive, then the woman's body may begin to secrete anti-Rh antibodies to foreign antigens. During the first pregnancy, very few of them are produced, and the girl bears and gives birth to an absolutely healthy child.

During abortion, the body becomes sensitized (increased sensitivity and accumulation of antibodies). In the next pregnancy (if the child's Rh is also positive), there is repeated contact with foreign proteins, which is almost always accompanied by an active release of specific anti-Rh antibodies.

What is hemolytic disease of the newborn?

A disease characterized by the pathology of red blood cells, with their accelerated destruction and release of indirect bilirubin. This condition is associated with an immunological (antigen-antibody) reaction of the blood of the child and mother. Most often, hemolytic disease of the fetus develops with an Rhesus conflict (usually manifested during the second or third pregnancy).

Important! It happens that a woman has a positive Rh, but an immunological reaction develops - this means that there has been a conflict over other antigenic systems. In any case, the conflict between mother and fetus develops after the previous sensitization of the woman's body.

Where did the information about the problems of conception in partners come from?

There is a lot of information on the Internet about the incompatibility of partners during conception on various grounds: according to the blood type according to the ABO system and the Rh factor. And if everything is clear with the last blood indicator from the above explanations, then even gynecologists have not heard about the problems of conceiving a child and pregnancy due to different groups, whether it is 1 or 2 positive in men, 3 or 4 negative in women.

This information is probably a distorted version of various physiological processes in the human body. Therefore, if there are doubts when planning because of ABO affiliation, or there are real difficulties with conceiving a baby, then it is better to consult an obstetrician on this issue and dispel your doubts once and for all.

When are couples incompatible?

If a married couple who has been sexually active for a long time fails to conceive a child, they should think about immunological incompatibility. This type of incompatibility can be described as a negative reaction of the female body to the partner's sperm. That is, with immunological incompatibility, the woman's immunity perceives spermatozoa as foreign antigens, and produces antisperm antibodies that prevent fertilization.

Antibodies can appear not only in the female body. They are also found in semen. In large numbers, they are capable of destroying spermatozoa, making it impossible for a woman to be fertilized. If the spermatozoa manage to survive and reach the egg, there is a threat of developing fetal pathology or miscarriage. Therefore, when planning a pregnancy, both partners need to be examined.

Aristotle believed that the genes and external characteristics inherited by a child at conception come not only from mom and dad, but also from all the men with whom a woman had sexual relations before pregnancy, the first sexual partner is especially important. This the theory of inheritance of traits from all sexual partners was called "Telegony".

Proponents of this idea note that there were cases when a woman and a Caucasian man had a child with a dark skin color. At the same time, the girl had previously met with a Negroid man, but had no pregnancies from him. Science explains this by the manifestation of a recessive gene from distant ancestors.

Tables of inherited indicators

Some parents are surprised by the blood type of their child. Sometimes she is different from the group of both father and mother, which gives rise to conflict situations in a young family that is not familiar with Mendel's laws of inheritance.

Australian scientist Gregor Mendel discovered that From each parent, the baby receives one gene. So, he will have one gene from a pair from his mother, and the second from his father. Genes are dominant and recessive. Dominant genes always appear, while recessive ones are stored in the genotype, but appear only when two recessive genes are combined in one pair.

According to the AB0 system, dominant genes are A and B, recessive 0. That is, if one parent has group I (0), and the other II (A) or III (B), the child at conception will inherit the A0 or B0 genotype and the second or third groups. In the table, we will consider all possible options from the first negative to the fourth positive blood type for conceiving a child and the likelihood of a conflict:

Dad mom	First	Second	Third	4th
First	I (100%)	I (50%) II (50%)	I (50%) III (50%)	II (50%) III (50%)
Second	I (50%) II (50%)	I (25%) II (75%)	I (25%) II(25%) III (25%) IV (25%)	II (50%) III (25%) IV (25%)
Third	I (50%) III (50%)	I (25%) II(25%) III (25%) IV (25%)	I (25%) III (75%)	II (25%) III (50%) IV (25%)
4th	II (50%) III (50%)	II (50%) III (25%) IV (25%)	II (25%) III (50%) IV (25%)	II (25%) III (25%) IV (50%)

It is clear from this table that it is not necessary for the child's blood type to match that of one or both parents.

You can also determine the likelihood of a child inheriting the Rh factor. Positive Rh dominates over negative. There are three types of Rh genotype: DD, Dd, dd. If at least one parent has the DD genotype, the child will inherit Rh positive. If the Rh-positive parent has the Dd genotype, the child can be either Rh-positive or Rh-negative.

Pregnancy and blood types of parents is an important issue that should be considered by a young family. At the first visit to the antenatal clinic, a pregnant woman donates blood to determine the group and Rh affiliation.

In the case of different Rh factors of the spouses, the pregnancy will take place under the increased attention of the antenatal clinic. it increased attention will help to identify the likelihood of a risk of conflicts on the Rh factor and will be the key to a successful pregnancy.

Useful video

We invite you to watch a video about the Rh factor when planning a pregnancy:

Blood is the internal environment of the body, formed by liquid connective tissue. Blood consists of plasma and formed elements: leukocytes, erythrocytes and platelets. Blood group - the composition of certain antigenic characteristics of erythrocytes, which are determined by identifying specific groups of proteins and carbohydrates that make up the membranes of erythrocytes. There are several classifications of human blood groups, the most significant of which are the AB0 classification and the Rh factor. Human blood plasma contains agglutinins (α and β), human erythrocytes contain agglutinogens (A and B). Moreover, of proteins A and α, only one can be contained in the blood, as well as of proteins B and β. Thus, only 4 combinations are possible that determine a person's blood type:

α and β define 1 blood group (0);
A and β determine the 2nd blood group (A);
α and B determine the 3rd blood group (B);
A and B determine the 4th blood group (AB).

The Rh factor is a specific antigen (D) found on the surface of red blood cells. The widely used terms "Rh", "Rh-positive" and "Rh-negative" refer specifically to the D-antigen and explain its presence or absence in the human body. Blood group compatibility and Rh compatibility are key concepts that are individual identifiers of human blood.

Blood type compatibility

The theory of blood group compatibility emerged in the mid-20th century. Hemotransfusion (blood transfusion) is used to restore the volume of circulating blood in the human body, to replace its components (erythrocytes, leukocytes, plasma proteins), to restore osmotic pressure, with aplasia of hematopoiesis, infections, burns. The transfused blood must be compatible both in group and in Rh factor. The compatibility of blood groups is determined by the main rule: the erythrocytes of the donor should not be agglutinated by the plasma of the receiving party. So, when the agglutinins and agglutinogens of the same name (A and α or B and β) meet, the reaction of sedimentation and subsequent destruction (hemolysis) of erythrocytes begins. Being the main mechanism of oxygen transport in the body, blood ceases to perform the respiratory function.

It is believed that the first 0(I) blood group is universal, which can be transfused to recipients with any other blood group. The fourth blood group AB (IV) is a universal recipient, that is, its owners can be transfused with blood of any other groups. As a rule, in practice, they are guided by the rule of exact compatibility of blood groups, transfusing blood of one group, taking into account the Rh factor of the recipient.

1 blood group: compatibility with other groups

Owners of the first blood group 0(I) Rh– can become donors for all other blood groups 0(I) Rh+/–, A(II) Rh+/–, B(III) Rh+/–, AB(IV) Rh+/–. In medicine, it was customary to talk about a universal donor. In case of 0(I) Rh+ donation, the following blood types can become recipients: 0(I) Rh+, A(II) Rh+, B(III) Rh+, AB(IV) Rh+.

Currently, blood type 1, which has been proven compatible with all other blood groups, is used for blood transfusion to recipients with a different blood type in extremely rare cases in volumes not exceeding 500 ml. For recipients with 1 blood type, compatibility will be as follows:

with Rh+, both 0(I) Rh– and 0(I) Rh+ can become a donor;
with Rh–, only 0(I) Rh– can become a donor.

2 blood group: compatibility with other groups

2 blood group, which compatibility with other blood groups is very limited, can be transfused to recipients with A (II) Rh + / - and AB (IV) Rh + / - in the case of a negative Rh factor. In the case of a positive Rh factor Rh + group A (II), it can be transfused only to recipients A (II) Rh + and AB (IV) Rh +. For owners of blood type 2, compatibility is as follows:

with own A(II) Rh+, the recipient can receive the first 0(I) Rh+/– and the second A(II) Rh+/–;
with own A(II) Rh–, the recipient can receive only 0(I) Rh– and A(II) Rh–.

Blood type 3: transfusion compatibility with other blood groups

If the donor is the owner of blood group 3, the compatibility will be as follows:

with Rh+, recipients are B(III) Rh+ (third positive) and AB(IV) Rh+ (fourth positive);
at Rh–, B(III) Rh+/– and AB(IV) Rh+/– become recipients.

If the recipient is the owner of blood group 3, the compatibility will be as follows:

for Rh+, donors can be 0(I) Rh+/–, as well as B(III) Rh+/–;
with Rh–, owners of 0(I) Rh– and B(III) Rh– can become donors.

4 blood group: compatibility with other groups

Owners of the 4th positive blood group AB (IV) Rh + are called universal recipients. So, if the recipient has a 4th blood group, the compatibility will be as follows:

with Rh+, donors can be 0(I) Rh+/–, A(II) Rh+/–, B(III) Rh+/–, AB(IV) Rh+/–;
with Rh–, donors can be 0(I) Rh–, A(II) Rh–, B(III) Rh–, AB(IV) Rh–.

A slightly different situation is observed when the donor has the 4th blood group, the compatibility will be as follows:

at Rh+ the recipient can be only one AB(IV) Rh+;
with Rh–, recipients can become owners of AB(IV) Rh+ and AB(IV) Rh–.

Blood type compatibility for conceiving a child

One of the key meanings of the compatibility of blood groups and Rh factors is the conception of a child and the bearing of a pregnancy. Compatibility of blood types of partners does not affect the likelihood of conceiving a child. The compatibility of blood types for conception is not as significant as the compatibility of Rh factors. This is explained by the fact that when an antigen (Rhesus factor) enters an organism that does not have it (Rh-negative), an immunological reaction begins, in which the recipient's body begins to produce agglutinins (destroying proteins) to the Rh factor. When Rh-positive erythrocytes enter the blood of a Rh-negative recipient again, agglutination (adhesion) and hemolysis (destruction) reactions of the resulting erythrocytes occur.

Rh-conflict - the incompatibility of the blood groups of the Rh-negative Rh- mother and the Rh + fetus, which results in the breakdown of red blood cells in the child's body. The blood of the baby, as a rule, enters the mother's body only during childbirth. The production of agglutinins to the antigen of the child during the first pregnancy is quite slow, and by the end of pregnancy does not reach a critical value that is dangerous for the fetus, which makes the first pregnancy safe for the child. Rhesus-conflict conditions during the second pregnancy, when agglutinins are preserved in the Rh- mother's body, are manifested by the development of hemolytic disease. Rh-negative women after the first pregnancy are recommended the introduction of anti-Rh globulin in order to break the immunological chain and stop the production of anti-Rh bodies.

Video from YouTube on the topic of the article: