There are plans to get pregnant, but how compatible are we? Which indicator is important - blood type or Rh factor? What do you need to know about the compatibility of people by blood type in sexual and family relationships? The ratio of blood groups at conception.

Blood group compatibility is information that is often decisive. Knowing compatibility allows you to quickly find a donor for blood transfusion, as well as avoid a difficult pregnancy and the development of pathologies in the embryo.

Which blood type is suitable?

Blood is a substance that contains plasma and formed substances. There are several classification systems, among which the most common is the AB0 system, according to which this biological material is divided into 4 types: I, II, III, IV.

Plasma consists of two types of agglutinogens and two types of agglutinins, which are present in a specific combination:

In addition, plasma may contain a specific antigen. If it is present, then the person is considered to have . If absent, negative.

When a person requires a transfusion, it is necessary to know which blood groups are compatible and which are not. Through numerous studies and experiments, scientists have found that I is universal, which is suitable for all others. This blood can be transfused to each other. IV (positive Rh factor Rh+) is also characterized by versatility; biological material of all others can be transfused into such blood.

Detailed characteristics of the four groups:

I - universal. People with a positive Rh factor have universal donor material, since it can be used for transfusion in any case. But recipients of this biological fluid are less fortunate - they only require single-group material. According to statistics, 50% of the world population have a universal blood composition.
II - inferior in versatility to the first. As a donor material, it is suitable only for owners of the second and fourth.
III - suitable only for owners of the third and fourth groups, provided they have the same Rh factor. The recipient of the third group can receive biomaterial from the first and third.
IV is a rare type of biological material. Recipients can accept any blood, but can only become donors for members of their own group.

Compatibility diagram by group for human blood transfusion:

Give away	Accept
1	1, 2, 3, 4	1
2	2, 4	1, 2
3	3, 4	1, 3
4	4	1, 2, 3, 4

The issue of compatibility is also taken into account in the field of family planning. The health of the mother and the unborn child depends on the group and Rh factors of the parents, therefore, before planning conception, you should get tested. Blood compatibility for conceiving a child is presented in the table.

Compatibility table:

		Father
		1	2	3	4
Mother	1	+	—	—	—
	2	+	+	—	—
	3	+	—	+	—
	4	+	+	+	+

“+” - compatible;
“-” - conflict.

First group

It does not contain antigens, so it is compatible in any case. The first positive characteristic is characterized by universality. During transfusion, 1 positive can be combined with II, III and IV, but it only accepts its own kind. The first negative is valued for the compatibility of blood for transfusion to any person in an emergency. But it is used in small quantities (no more than 500 ml).

For routine transfusion, single-group biological material should be used, and the Rh factors of the recipient and donor should be identical.

Options for compatibility of group 1 for conception:

There is a pattern in inheritance. If both parents have the first group, then the child will inherit it with 100% probability. If parents have 1 and 2 or 1 and 3, then the probability of having babies with groups 1 and 2 or 1 and 3 is 50/50%.

Second group

The presence of antigen A in it allows it to be combined with 2 and 4, which include this antigen. In terms of compatibility, 2 positive conflicts with 1 and 2. The reason is the presence of antibodies to antigen A in the latter.

If a person is second positive, then only the same blood group 2 is suitable for transfusion. If you are Rh negative, you need to look for a donor with Rh negative biomaterial. In case of emergency, blood type 2 can be combined with 1 Rh-.

The second group is compatibility when planning pregnancy:

Third group

It is not characterized by a combination with 1 and 2 (there are antibodies to antigen B), since group 3 contains antigen B. A person with the third negative is transfused only with identical biomaterial. In emergency cases, the first negative is used, subject to regular monitoring of compatibility.

Blood type 3 positive is rare, so it is difficult to find a donor for transfusion. A suitable biomaterial for transfusion to a person with a third positive is 3 Rh+ and Rh-, as well as 1 Rh+ and Rh-.

Blood group compatibility for conceiving a child:

Fourth group

It contains antigens A and B, for this reason, in relation to donation, group 4 is suitable only for people with the same group.

People with the fourth group are considered universal recipients, since any blood can be transfused to them. And rhesus does not always matter:

4 positive - full compatibility with others (1, 2, 3), regardless of the Rh factor.

You need to know which biomaterial is suitable for 4 negative. Anyone, but only with negative Rh.

Blood group 4 - compatibility with other groups during pregnancy:

Which blood types are incompatible?

Blood group compatibility during transfusion allows you to avoid situations where the body does not accept unsuitable donor blood. Transfusion shock is considered a dangerous complication of this situation, so you need to know which types of blood are incompatible. Moreover, when transfusion occurs, the Rh factor (Rh) matters.

The Rh factor is a protein that is found on the membrane of blood cells and exhibits antigenic properties. The transmission of this protein occurs by inheritance. Based on its presence, a conclusion is drawn regarding rhesus:

positive (Rh+) - protein is present on red blood cells;
negative (Rh-) - there is no protein on the red blood cells.

Transfusion of donor material should be carried out only taking into account rhesus. It is impossible for cells of Rh-positive biomaterial to interact with Rh-negative cells. Otherwise, the process of destruction of red blood cells begins.

Incompatibility:

I Rh+ - with everyone who has Rh-;
II Rh- - with I and III;
II Rh+ - with all except II and IV Rh+;
III Rh- - I and II;
III Rh+ - with all except III and IV Rh+;
IV Rh+ - c I, II, III and IV Rh-.

The types of blood that are incompatible for conceiving a child are the same as in the case of transfusion.

Rhesus conflict

Many people are interested in how the biomaterial of parents can affect the conception of a child and how the Rh factor affects conception. It has been established that parents of different groups with the same Rh factor are suitable for conceiving a healthy baby. If the biomaterial of the parents matches the background of different Rhesus, then difficulties in conceiving are possible.

The problem is that in case of incompatibility, a conflict regarding the Rh factor is possible - negative and positive red blood cells stick together, this is accompanied by a number of complications and pathologies.

If the positive Rh factor of the pregnant woman is stronger, then the risk of conflict is minimal. Pregnancy in women with Rh- will proceed normally, provided that the partner has the same Rh factor. If the partner has Rh+, then there is a high probability that the child will inherit it. In such a situation, Rh conflict between mother and child may arise. The Rh of the unborn child is determined based on the indicators of the mother and father.

Influence of Rh factors:

In practice, Rh conflict occurs in no more than 0.8% of cases. But this problem is given special attention, because it carries danger. Rh-positive fetal plasma poses a threat to a pregnant woman with Rh-negative plasma, so the woman’s body starts producing antibodies. Hemolysis occurs - a process in which antibodies begin to interact with the red blood cells of the embryo and have a detrimental effect on them.

During the metabolic process, the fetal bloodstream is enriched with nutrients and oxygen. At the same time, waste products of the embryo enter the bloodstream of the pregnant woman. A partial exchange of red blood cells occurs, as a result of which some of the baby’s positive cells enter the mother’s blood, and some of her cells enter the fetal bloodstream. In a similar way, antibodies enter the embryo’s body.

It has been noted that Rh conflict occurs less frequently during the first pregnancy than during the second. When the mother's cells first interact with the embryo's cells, large IgM antibodies are produced. They rarely and in small quantities enter the fetal bloodstream, so they are not capable of harm.

During the second pregnancy, IgG antibodies are produced. They are small in size, so they easily penetrate into the bloodstream of the unborn baby. As a result, hemolysis continues in his body and the toxic substance bilirubin accumulates. Fluid accumulates in the fetal organs, and the functioning of all systems in the body is disrupted. After birth, this process continues for some time, which aggravates the condition of the newborn. In such cases, a diagnosis is made.

In severe cases, Rh conflict negatively affects conception - the pregnant woman has a miscarriage. For this reason, pregnant women with Rh- need careful monitoring of their condition and all tests and studies.

Knowing blood compatibility allows you to prevent a number of complications, sometimes incompatible with life. And this applies not only to the transfusion procedure. Finding out compatibility should be one of the important stages in planning conception. This will help eliminate severe pregnancy, miscarriages, and the development of defects and pathologies in the child.

The desire to become parents and have a complete family is a natural need for many married couples. Planning a baby is an important stage in the life of spouses. That is why expectant mothers and fathers strive to obtain as much information as possible on all issues related to a future pregnancy. One of the important points worth paying attention to is blood compatibility for successful conception and subsequent pregnancy. Routine examinations at the stage of preparation for pregnancy will identify possible disorders, as well as situations requiring additional medical monitoring.

The term “blood type” is familiar to everyone. But not everyone knows how important this characteristic is for the further continuation of the human race.

Blood groups for conception - what are they?

Each parent has one of four blood groups - I (or O), II (or A), III (or B) and IV (or AB). Belonging to one or another category is determined by the presence of certain proteins - agglutinins α and β in plasma and agglutinogens A and B in red blood cells - erythrocytes. These “protein combinations” formed the following blood groups:

The first group is group (O), determined by the presence of α and β antibodies, but no antigens.
The second group, group (A), is characterized by the presence of A antigen and β antibodies.
The third group, group (B), is determined by the presence of proteins α and B.
The fourth group is group (AB), characterized by the presence of antigens A and B, but no antibodies.

Many parents wonder whether their blood type affects the successful conception and subsequent course of pregnancy. It’s worth mentioning right away that the group does not influence these processes in any way. However, depending on the initial data of the parents, one can assume a certain risk of developing certain deviations. Knowing the blood type of the parents, you can calculate the blood type of the unborn baby as a percentage. The results of blood group compatibility for conceiving a child are clearly demonstrated in the table below.

So, if both parents are carriers of the first blood group, then their baby with a 100% probability will also have this group.
The combination of the first and second or first and third groups will give an equal probability of having babies with the first and second, and first and third blood groups, respectively.
The most unpredictable is the combination of the second and third groups, since in this case your little one can have absolutely any blood type.

Immunological conflict

A responsible approach to planning and bearing a baby can significantly reduce possible negative phenomena that sometimes happen during the 9 months of waiting for a replenishment. One of the preventive tests - determining the compatibility of partners by blood group - may not play a special role for conception, but for the further development of the toddler its importance can be very great. A possible conflict between mother and baby in her womb due to the Rh factor is practically nothing new to anyone. But not everyone knows about the compatibility of blood in the mother-baby connection for conceiving and bearing a child. There are some combinations that can cause complications during pregnancy.

Blood type 1: compatibility for conception. If the mother has the first blood group, and the father of the child has any other, a conflict under the ABO system is possible. If a child has a blood type other than the first, then when they meet the mother’s blood cells, α and β antibodies destroy red blood cells with a foreign antigen. However, there is no need to panic in advance. The presence of the blood type situation described above does not always provoke a conflict, and even without outside intervention, healthy children are born. If the expectant mother wants to play it safe, then after the 30th week she can be tested (once a month) for group antibodies. This conflict (if detected) is less dangerous than the Rhesus conflict. Moreover, with each subsequent pregnancy, the risk of its occurrence decreases more often.
Blood type 2: compatibility for conception. When the blood of the second group circulates in the expectant mother’s body, the likelihood of incompatibility with the baby arises if the father’s blood is of the third and fourth groups.
Blood type 3: compatibility for conception. More careful attention is required when the child’s father has group A or AB (second and fourth, respectively), and the mother has the third group.
Blood type 4: compatibility for conception. If a woman has this blood type, then there is no likelihood of conflict.

This information in no way suggests that people with “possibly incompatible” blood types should not have children or that such a pregnancy will obviously be problematic. It’s just that future mothers and fathers should know that a certain combination of blood groups may require additional attention (blood tests, ultrasound) on their part. If antibodies are detected in the blood of a pregnant woman, treatment is not prescribed immediately and not always - the doctor monitors the dynamics of this indicator. If intervention is necessary, therapy is prescribed. The most effective and safe method is plasmapheresis, although it also has a number of contraindications. When a conflict is detected, the optimal therapy is selected by the doctor.

Blood compatibility for conceiving a child: pregnancy and Rh factor - introduction

Almost every person has heard the term “Rh factor”. However, not everyone fully knows and understands what information it contains. A special protein (antigen) that is located on the surface of red blood cells is the Rh factor. In cases where this protein is detected, they speak of a positive Rh factor; if it is not there, the person’s blood has a negative Rh factor. About 15% of the population does not have the antigen. Laboratory analysis allows you to determine whether you belong to one type or another.

You donate blood.
The laboratory technician determines the presence or absence of a specific protein and makes a conclusion about a positive or negative Rh factor.

Laboratory analysis is designed to determine the compatibility of blood groups and Rhesus to eliminate problems not so much during conception, but during the subsequent course of pregnancy. If the Rh factor of the expectant mother and father is the same, then problems almost never arise. But, unfortunately, this does not always happen.

Blood compatibility for conceiving a child - the occurrence of Rh conflict

Young people love each other, dream of having a baby together and don’t even think about any “Rhesus”. And suddenly a Rhesus conflict arises.

Causes of Rh conflict

Situations when the child’s father does not have protein on his red blood cells, but his mother has it (or vice versa) require additional attention. That is why, even before pregnancy, it is recommended to undergo tests to determine the compatibility of the parents’ blood in order to exclude the influence of negative factors both for conception and subsequent pregnancy. Moreover, in some cases, even before the appearance of a little man in the womb of a woman, the expectant mother needs to undergo therapy to prevent diseases and rejection of the fetus.

Let's look at these 2 cases in more detail:

The mother's Rh is positive, the father's Rh is negative. In most cases, this situation does not pose any threat to either the woman or the baby in her womb. Even if the baby has a negative Rh factor, a conflict will not arise, because the woman's blood contains the antigen, but the child's blood does not.
The mother's Rh is negative, the father's Rh is positive. But this situation is already dangerous. If the baby “takes” the father’s antigens, then a conflict arises between the immune systems of the mother and the fetus. The woman’s body is trying to get rid of the foreign object. The production of protein compounds—antibodies—begins, which are designed to eliminate the baby’s red blood cells.

That is why, if a woman donates blood to determine her group and Rh affiliation, an antigen is detected during the analysis, then the father’s Rh is often not even interested in her.

Rh conflict and subsequent pregnancies: how to prevent

The baby's Rh status is formed in the very early stages of pregnancy (at 6-8 weeks). If it is the first pregnancy, then even the presence of a special protein in the baby’s blood almost never leads to a conflict. This is explained by the fact that the first meeting of a woman’s immune system with the baby’s antigens leads to the production of class M immunoglobulin. The structure of this substance does not allow it to penetrate the placental barrier, and the baby is safe. However, information about this “meeting” is stored in the so-called cell memory. And during subsequent pregnancies, group G antibodies are produced, which easily penetrate the baby and can cause fetal death or premature termination of pregnancy. G-antibodies, once appearing in the blood, remain in the body for life.

A woman should also take into account that the production of immunoglobulin does not depend on whether the pregnancy ended with the birth of a baby or was artificially terminated, as well as on its location - uterine or ectopic attachment of the fetus. To prevent the occurrence of conflict in the future (2 and subsequent pregnancies), after the first pregnancy, within 48 hours, the woman is injected with anti-Rhesus immunoglobulin, which “erases the memory” of the presence of foreign cells. The sooner the drug is administered, the greater the likelihood of its effectiveness. Thus, the compatibility of Rh blood factors is of utmost importance not only for conception, but for the subsequent successful growth and development of the toddler.

Consequences of lack of therapy for Rhesus conflict

An active attack from the mother’s body often leads to not very good consequences for the baby. The lack of adequate and timely therapy can cause the baby to develop hemolytic disease. Its manifestations (forms) can be as follows:

Development of anemia. This is the mildest scenario and the prognosis is most often favorable.
Postpartum jaundice. This is a more severe form of disorders, which is manifested not only by yellowing of the baby’s skin, but also by anemia, enlargement of the liver and spleen. There is an increased level of bilirubin.
The edematous form is the formation of dropsy of the heart or brain. This is the most severe form of pathology. If the antibody attack occurs early, a miscarriage most often occurs. Defeat in subsequent weeks leads to the birth of a baby in a very serious condition. There is pallor and severe cardiopulmonary failure.

As a consequence of hypoxia, deviations in the mental development of the child are possible.

That is why it is very important not only to be examined in advance, but also to monitor your health throughout pregnancy. Timely start of therapy will allow you to give birth to a healthy baby at term.

All your friends already have children, and you and your significant other decided that it’s time for you to have offspring too. Of course, many future parents do not want to leave things to chance, wanting to prepare thoroughly. After all, the baby’s health depends on it. If to conception If you don’t prepare and check whether you are compatible, problems may arise both during pregnancy and after the baby is born.

Experts have found that about 15% of couples experience incompatibility problem. If this problem is not identified and prevented in a timely manner, the pregnancy can be terminated at any time. The same is to be expected if the couple is incompatible at the immunological level.

It is for this reason that it is so important that both the woman and the man undergo all examinations before conceiving a child.

What kind of incompatibility happens?

Immunity.

Immune system women are able to produce antibodies that fight the sperm of a man, who must act as the father of the unborn baby. This is, so to speak, an allergic reaction to the sperm of a certain man. A woman produces large quantities of antisperm antibodies. There are cases when a man’s body produced such antibodies.

This does not mean that the couple will not be able to conceive. baby, but the likelihood of saving the child is very low. The situation is aggravated by the fact that this incompatibility is accompanied by certain diseases that affect the reproductive system of the expectant mother.

To eliminate this possibility, it is necessary to do before the moment of conception test, confirming or refuting immunological incompatibility.

Blood group.

At the moment of conception blood women and men mix and a new composition of the child’s blood is formed. A child can have absolutely any blood type, since when a fetus is born, 4 blood groups are formed simultaneously. However, their percentages are different. The blood of the parents is predominant.

If mom and dad have the same blood type, then in 95% of cases the child will have the same blood type as the parents. If the parents have different blood types, then the probability that the toddler will have one of them is approximately 25%. In 99% of cases, the baby becomes the owner of the maternal blood types and Rh factor.

Experts say that the best option is when a man’s blood type is higher than that of a woman. In this case, the baby will be healthier. For example, if you women the first group, then a man should have any other. If a woman has a third blood group, then a man should have a fourth. Pregnancy proceeds best if the parents have the same blood groups.

Rh factor.

If a man and a woman have different Rh factors, there is a risk that the woman’s body will reject the developing fetus, considering it a foreign body. However, in comparison with the immunological factor, with this incompatibility it is quite possible to become pregnant and give birth to a baby. It is important to visit your doctor regularly and undergo all examinations prescribed by him.

You need to know that Rh conflict can arise if a woman is Rh negative and men Rh positive.

The risk increases during childbirth when the mother's blood combines with the father's blood. The immune system begins to produce antibodies that fight the man's Rh positive blood. However, today doctors have already found a way to solve this problem.

The problem of the Rh factor can also appear during the period of planning a second child. A woman can easily become pregnant, but the course pregnancy and its completion may be disastrous. To save the baby you will have to make a lot of effort. However, with a strong desire, everything can work out, so don’t panic ahead of time.

Genetics.

In most cases genetic compatibility Those couples are examined who, according to all other examinations, are fine, but they still cannot “get pregnant” or the woman cannot carry a child.

Every cell of our body has a protein on its surface called HLA. If the body is healthy, then these proteins can detect a foreign body and let the immune system know about it, which in turn produces antibodies for protection. Pregnancy is also a kind of invasion of a foreign body. As a rule, after conception, blocking antigens are formed in a woman’s body, which are responsible for protecting the placenta and fetus from rejection.

If a man's HLA is similar to a woman's HLA, then the body does not produce antibodies. The child's condition may be at risk.

When the issue of conceiving a child is of great importance, especially if it has not been possible to get pregnant for a long time, many couples turn to specialists. In fact, a family planning office must be visited from the very beginning. The examination will help determine all factors of compatibility between parents so that the baby is born healthy. Blood group compatibility for conception plays a particularly important role.

What effect does group compatibility have on conception?

The membrane of human red blood cells contains many antigens, which are protein or carbohydrate molecules. Antibodies can be formed in the blood serum to these antigens. By binding to antigens, antibodies cause the destruction of red blood cells (hemolysis). Over 4 dozen antigenic systems are known, but the most famous are the AB0 systems and the Rh factor, which influences the success of bearing a child. All doctors agree that the main influence on the fact of conception is the health status of the parents, and stories about the incompatibility of certain blood groups, which leads to the inability to get pregnant, are a myth.

If partners, despite unprotected sexual intercourse, fail to conceive at the moments of ovulation, this does not indicate incompatibility of groups, but the presence of serious diseases, often of the reproductive system. Common ones are:

diseases of the genitourinary system caused by infection;
diseases of the thyroid gland, endocrine system;
obstruction of the fallopian tubes, other similar pathologies;
problems with sperm motility in men, others.

As for infectious diseases of the genitourinary system, both spouses have them at once, so treatment is prescribed to both the husband and wife. In other cases, only one partner may need therapy.

Of course, genetic inheritance is an important factor determining the possibility of normal development of a child, so many women worry about blood type compatibility. But, as already mentioned, the conception and full development of the embryo is influenced by the compatibility of the parents according to the Rh blood factor.

What you need to know before conceiving

The main thing you need to know is what group both partners have. In addition to analysis to determine it, it is also recommended to test for antibodies to the Rh factor. Below we describe in more detail in which cases a Rh conflict can occur that interferes with bearing a healthy child.

Also, every expectant mother needs to find out more information about the following facts:

In some cases, problems can arise not only due to Rh factors, but also as a result of differences in the group itself: a woman has the second, a man has the third/fourth; for a woman it is the third, for a man it is the second/fourth.
According to statistics, the most problems with bearing a fetus occur in women of the fourth group, so they are usually under special medical supervision.
The ability to conceive is reduced not only due to blood type incompatibility, it can also be affected by pelvic diseases, fibroids, cysts, and other neoplasms.

To prevent possible problems, it is recommended to visit a gynecologist or a family planning office before conceiving.

Blood group compatibility table - I, II, III, IV

Many couples strive to find out the blood type of the unborn baby; this can be done without waiting for his birth, and earlier than the sex of the child on an ultrasound. To do this, it is enough to know the groups of both parents in order to predict the blood type of the unborn baby with a certain accuracy.

The table below helps determine the combination of different parent groups among themselves:


I positive and negative	I	I and II	I and III	II, III
II positive and negative	I and II	I and II	I, II, III, IV	II, III, IV
III positive and negative	I and III	I, II, III, IV	I, III	II, III, IV
IV positive and negative	II, III	II, III, IV	II, III, IV	II, III, IV

The table shows that when the parents’ groups are the same (except for 4), then the child will either have exactly the same one, or 1; if they are different, he may have one of them, or maybe a completely different one. In some cases, for example, when parents have groups 2 and 3, children can have absolutely any group.

Rhesus conflict during conception

Rh conflict is a serious problem that can be an obstacle to pregnancy or successful pregnancy. It occurs in cases where a woman has a negative Rh factor and a man has a positive Rh factor, while the fetus acquires a positive gene from the father.

To understand what happens in the female body, why it rejects the fetus, you need to have a shallow knowledge of genetics. When the embryo's red blood cells carry antigen proteins related to the positive Rh factor (Rh+), the mother's body perceives the child's red blood cells as foreign bodies and produces antibodies to them. These antibodies bind to antigens on the surface of red blood cells and destroy them.

However, the first pregnancy most often proceeds normally, because the blood circulation of the fetus and mother is normally isolated from each other. Only during childbirth does the blood of mother and child mix, and then the maternal body becomes sensitized and the production of antibodies begins. By the next pregnancy, antibodies to Rh-positive red blood cells are already circulating in the maternal blood. Their peculiarity is that they are able to penetrate the blood of the fetus and destroy its red blood cells.

Let's look at how the Rh factor is inherited.

Mother's Rh factor	Father's Rh factor
Mother's Rh factor	Rh+ (DD)	Rh+ (Dd)	Rh- (dd)
Rh+ (DD)	Rh+ (DD) - 100%	Rh+ (DD) - 50% Rh+ (Dd) - 50%	Rh+ (Dd) - 100%
Rh+ (Dd)	Rh+ (DD) - 50% Rh+ (Dd) - 50%	Rh+ (DD) — 25% Rh+ (Dd) - 50% Rh- (dd) - 25%	Rh+ (Dd) - 50% Rh- (dd) - 50%
Rh- (dd)	Rh+ (Dd) - 100%	Rh+ (Dd) - 50% Rh- (dd) - 50%	Rh- (dd) - 100%

Cases where Rh conflict occurs are highlighted.

As you can see from the table, even if both parents are carriers of a positive Rh factor, this is not a guarantee that they will not have a Rh negative child.

Important! Some partners do not know their Rh factor and are not even aware of the consequences of their negligent attitude towards the issue of conception. Doctors urge everyone to find out the characteristics of their blood type, doing this not only during a transfusion in a critical situation, but in advance.

Consequences of Rh conflict for the fetus

Hemolytic disease of the fetus is an inevitable consequence of Rh conflict during conception. If the embryo manages to survive, serious changes begin to occur to it. The mother’s body continues to intensively produce antibodies, when they penetrate the fetus’s bloodstream, binding to its Rh-positive red blood cells, the latter are destroyed. This happens in the spleen of the unborn child; the newborn has an enlarged spleen.

Hemoglobin is released from collapsing red blood cells, which, breaking down, turns into bilirubin through several successive transformations. It is the increased content of bilirubin, which has a yellow color, in the blood, organs and tissues that causes the yellow color of the child’s skin - this disease is called hemolytic jaundice of newborns.

Bilirubin is neurotoxic; it can affect both the cortex and subcortical structures of the brain. Long-term consequences may include paralysis, hearing impairment, and mental retardation.

Also, due to the breakdown of red blood cells, their number in the blood decreases, and the child develops hemolytic anemia. Since there are few red blood cells that carry oxygen, the tissues of the fetus and newborn suffer from a lack of oxygen - hypoxia and intrauterine growth retardation occurs.

There are three main forms of hemolytic disease in a newborn:

Anemic. The easiest option. The main symptom is excessively pale skin, enlarged liver and spleen. Red blood cells and hemoglobin are reduced in the blood. Treated with blood transfusion. Usually there are no serious health problems in the future.
Jaundice. In addition to anemia, there is jaundice, enlargement of the liver and spleen. The skin may take on an intense yellow or even yellow-brown color. Amniotic fluid may be yellow in color. Reflexes in newborns are reduced, they are lethargic, and suck poorly. Requires urgent treatment.
Edema. The most severe form. Massive intrauterine destruction of red blood cells leads to severe anemia, hypoxia, metabolic disorders, and tissue edema. The fetus dies before birth or is born in an extremely difficult condition with widespread edema. The skin is very pale and shiny. The child is lethargic, reflexes are depressed, severe cardiac and respiratory failure, severe enlargement of the liver and spleen, large, barrel-shaped abdomen.

Important! When registering a pregnant woman, the blood type and Rh factor of the mother and father must be determined to identify the risk of Rh conflict. Hemolytic disease can be recognized in the early stages if a timely ultrasound is performed with a mandatory study of placental blood flow, a blood test is performed at least 3 times to determine the concentration of anti-Rhesus antibodies, and consultations with the attending physician are required.

Rh factors that match each other

The most optimal for successful conception are the same Rh factors in partners, and it does not matter what group they have. For example, 2 positive and 3 positive combine perfectly; there can be no problems associated with blood incompatibility with conception or fetal development.

Problems arise when 1 negative and 1 positive are combined, and if it is negative, it is in a woman. As described above, it all depends on whose gene the fetus acquires; if the father’s is positive, then a Rh conflict will occur.

The Rh factor can be determined in most clinics by donating blood from a finger prick. You can also purchase a special test sold in pharmacies. The package usually contains an applicator, containers where the blood is placed, and special solutions. Doctors advise not to use such tests without special skills, but to contact laboratories.

Incompatibility between the organisms of mother and fetus can arise due to different Rh factors when Rh conflict occurs. Its consequences for the child can be different: the embryo may die in utero, or be born with a certain form of hemolytic disease. There is a possibility of a completely healthy baby being born. In any case, before planning a conception, every couple is recommended to contact a family planning center.

Issues of blood compatibility are a fairly pressing topic in 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 something happens that defies absolutely any logical justification. This happens especially often when determining blood compatibility for conception during family planning, pregnancy, or the need for a transfusion. All these paradoxes once again confirm that there is nothing absolute in medicine, since many things are still covered in secrets that humanity has yet to uncover. But what is already known deserves close attention.

Basic concept of 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 red blood cells, 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 involve 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. This largely 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 identical in Rh factor can be so!

Blood compatibility for conception

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

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

The compatibility of spouses when a woman is unable to get pregnant depends not on the compatibility of blood groups or the Rh factor, but on the immunological compatibility of the woman and the man. This means that antibodies are produced to the components of a particular male sperm in the woman’s body, which 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 baby with Rh positive blood. This can only affect the course of pregnancy and the condition of the fetus, but cannot be regarded as Rh incompatibility for conceiving a child;
A couple with different Rh factors can easily have healthy children. There is no need to ruin relationships because the Rhesus of the mother and fetus could potentially be incompatible. But you should definitely follow the family planning recommendations that experts will point out. Some of these recommendations are listed in the next section.

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

Blood compatibility during pregnancy

If a married couple decides to become pregnant, they must follow this process from the planning stage until the birth of the child. With regard to the potential possibility of Rh conflict during pregnancy, you should be wary of:

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 he is heterozygous (Rh is encoded by only one chromosome from the pair);
Spouses whose blood mixing could potentially result in an Rh-conflict pregnancy, with previous pregnancies and births. Their favorable outcome does not mean anything. On the contrary, the likelihood of developing maternal-fetal blood incompatibility increases with each subsequent pregnancy.

Blood group compatibility and the table are compatible with the Rh factor with possible options for its inheritance by the child.

Mother's Rh factor	Father's Rh factor	Probability of Rh-ness of the child	Probability of Rh-conflict pregnancy
Positive	Positive	If the parents are homozygous – 100% positive; If the parents are heterozygotes – 50% positive; If one of the spouses is homozygous and the other 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 child's blood will be Rh negative in 100% of cases.	There is no conflict pregnancy

Note: A homozygote is a person who contains identical genes on similar chromosomes. When they become part of the fetal chromosome set, they will unambiguously encode the synthesis of the Rh factor. A heterozygote contains such a gene in only one of the chromosomes, which significantly reduces the risk of inheriting it.

Important to remember!!!

The blood of an Rh-positive mother is compatible with any blood of the fetus;
The likelihood of a conflict regarding 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 factor 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, this is not feasible in practice. 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 recipient. Otherwise, inappropriate blood will not only not help, but will also cause the death of the patient.

With regard to donor compatibility, only red blood cell preparations (packed red blood cells and washed red blood cells) are considered. Before immediate blood transfusion, the compatibility of blood groups and Rh compatibility is 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, when an emergency blood transfusion is required in a matter of minutes, there is no time to determine compatibility. The only salvation remains a transfusion of whole blood or red blood cells on the principle of hypothetical compatibility. Its options are given in table form.

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

From the table the following practical conclusions can be drawn:

People with the first blood group are, but they themselves can only become recipients of 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 only possible if the donor's red blood cells do not contain the appropriate antibodies, which will cause their destruction after transfusion.

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