What is Rhesus conflict between mother and child. Rhesus conflict: causes and treatment

Blood incompatibility is not a contraindication to breastfeeding, but the method of feeding (natural or bottle feeding with expressed milk) will be advised by the doctor, depending on the severity of the baby's condition. In extremely serious conditions, he can be fed intravenously.

Human blood has two important characteristics - blood type (AB0 system) and Rh factor (Rhesus system). Most often, during pregnancy, there are problems with bearing due to incompatibility precisely according to the Rhesus system, so we will analyze it first.

What is the Rh factor?

Rh factor (Rh) is an erythrocyte antigen of the Rhesus system. Simply put, it is a protein located on the surface of red blood cells (erythrocytes).

People who have this protein are Rh+ positive (or Rh positive). Accordingly, a negative Rh Rh- (or negative Rh) indicates the absence of this protein in human blood.

What is Rhesus conflict and why is it dangerous for the fetus?

Rhesus conflict- the immune response of the mother's body to the appearance of a "foreign" agent inside itself. This is the so-called struggle of the bodies of the Rh-negative blood of the mother with the bodies of the Rh-positive blood of the child, which is fraught with the appearance of hemolytic anemia or jaundice, hypoxia, and even dropsy of the fetus.

During the first pregnancy, the blood flow of the mother and child function separately from each other and their blood does not mix, but during previous births (possibly also during abortions and miscarriages), the baby’s blood can enter the mother’s blood, and as a result, the body of a woman with a negative Rh -factor will develop antibodies to the antigen even before the next pregnancy. Therefore, a repeated pregnancy can end at an early stage with intrauterine death of the embryo, and as a result, a miscarriage.

The first pregnancy usually proceeds without complications, since the mother's blood does not yet have antibodies to the "foreign" blood of the child.

Simply put, the blood cells of the fetus penetrate the placenta into the blood of the pregnant woman, and if the blood is incompatible, the body of the expectant mother perceives the baby as a “stranger”, after which the protective reaction of the woman’s body produces special antibodies that destroy the baby’s blood cells.

The destruction of fetal red blood cells by antibodies is called hemolysis, which leads to anemia in the baby. At the same time, the condition of the pregnant woman does not worsen, and the woman is not even aware of the previous threat to the health of the baby.

When does Rh conflict occur during pregnancy?

With a positive Rh mother, the Rh conflict will never arise, no matter what the blood of the father of the child.

With a negative Rh, both future parents also have no reason to worry, the child will also have a negative Rh factor, it cannot be otherwise.

With a negative Rh factor in the blood of a pregnant woman and a positive one in the father of the child, the baby can inherit both the mother's Rh factor and the father's Rh factor.

If the father of the child is Rh-positive, homozygous, and has the DD genotype, the pregnant woman is Rh-negative, then in this case all children will be Rh-positive.

If the father is Rh-positive, heterozygous, and has the Dd genotype, and the pregnant woman is Rh-negative, then in this case a child can be born with both Rh-positive and Rh-negative factors (the probability in this case is 50/50).

Therefore, it is also important for a man to donate blood for the Rh factor with the determination of the genotype with a negative blood group in a woman planning a pregnancy or carrying a fetus.

With the likelihood of developing a Rh conflict, a pregnant woman is prescribed a blood test for the presence of Rh antibodies.

Table 1 - The likelihood of developing a Rh conflict during pregnancy

Judging by the table above, we can say that the Rh conflict occurs only when the pregnant woman is Rh negative and the father of the child is Rh positive, and only in 50 cases out of a hundred possible.

That is, it is not necessary to observe an Rhesus conflict during pregnancy. The fetus can also inherit a negative Rh from the mother, then there will be no conflict.

It should also be noted that during the first pregnancy, antibodies are produced for the first time, and therefore they are larger than during a second pregnancy. It is more difficult for large antibodies of the IgM type to penetrate the placental barrier into the blood of the child, as if they cannot “crawl through” the walls of the placenta, and during the next pregnancy, other, more “modified” antibodies of the IgG type are produced. They are smaller, and their ability to penetrate the walls of the placenta is much higher, which is more dangerous for the fetus. Then the antibody titer rises.

Therefore, primiparous women should not worry about the Rh conflict, just be vigilant (it is enough to determine the antibody titer once a month), and enjoy the pregnancy period, because there are cares for caring for the baby and his upbringing ahead.

Prevention and treatment of Rhesus conflict

During the first pregnancy (that is, there were no abortions and miscarriages in the past), for the first time, an analysis for antibodies is carried out from 18-20 weeks 1 time per month (up to 30 weeks), then from 30 to 36 weeks - 2 times a month, and after 36 weeks of pregnancy - 1 time per week.

With repeated pregnancy, they begin to donate blood for antibodies from 7-8 weeks of pregnancy. If the titer is not more than 1:4, then this analysis is taken once a month, and with an increase in titer - more often, once every 1-2 weeks.

An antibody titer of up to 1:4 inclusive is considered acceptable (normal) in a “conflict” pregnancy.

Titles 1:64, 1:128 and more are considered critical.

If there is a risk of developing a “conflict” pregnancy, but antibodies have never been detected before week 28 (or were detected, but not more than 1: 4), then later they may appear in significant quantities.

Therefore, for prophylactic purposes, pregnant women are injected with human anti-Rhesus immunoglobulin D at week 28, which block the work of the woman's immune system to destroy foreign bodies, i.e. after the injection, the woman's body will not produce antibodies that destroy the blood cells of the embryo.

An injection of immunoglobulin is advisable to carry out in the absence of antibodies in the blood of a pregnant woman, since in other cases it is simply useless.

The vaccine does not adversely affect the health of the mother and fetus, it is completely safe.

After the injection (provided that there are no antibodies in the blood shortly before the injection, or at least if their titer is not more than 1: 4), it is not reasonable to donate blood for antibodies, since a false positive result may be observed.

It is also advisable to monitor the baby's cardiac activity by regularly conducting cardiotocography (CTG), starting from the 26th week.

Doppler or doppler is an ultrasound examination of blood flow in the vessels of the fetus, in the uterine arteries and the umbilical cord.

If the fetus suffers, the blood flow velocity (V max) in the middle cerebral artery will be higher than normal. When this indicator approaches the mark of 80-100, an emergency CS is performed in order to prevent the baby from dying.

If there is an increase in antibodies, and the child's health is deteriorating, then this indicates the development of fetal hemolytic disease (abbreviated GBP), then it is necessary to carry out treatment, which consists in intrauterine blood transfusion of the fetus.

With a "conflict" course of pregnancy during an ultrasound examination, the following signs of hemolytic disease of the fetus can be observed:

• an increase in the abdomen of the fetus due to the accumulation of fluid in its abdominal cavity, as a result of which the baby takes the “Buddha pose”, spreading the bent legs to the sides;
• edema of the subcutaneous fatty tissue of the head (ultrasound shows a “double contour” of the fetal head);
• an increase in the size of the heart (cardiomegaly), liver and spleen;
• thickening of the placenta up to 5-8 cm (normal 3-4 cm) and expansion of the umbilical cord vein (more than 10 mm).

Due to increased swelling, the weight of the fetus will increase by 2 times compared to the norm.

If it is not possible to conduct a blood transfusion, then it is necessary to discuss the issue of early delivery. You can’t hesitate, and if the baby’s lungs have already formed (the 28th embryonic week or more), then it is necessary to perform labor stimulation, otherwise the pregnant woman risks losing the baby.

If the baby has reached 24 weeks, then a series of injections can be given to ripen the lungs of the fetus so that he can breathe on his own after an emergency delivery.

After the baby is born, he is given a replacement blood transfusion, plasmapheresis (blood filtration from dangerous cells) or phototherapy, otherwise the destruction of the baby's red blood cells will continue.

Modern generic resuscitation service is able to leave a premature baby even when he is born at the 22nd week of pregnancy, so in a critical case, entrust the saving of the baby's life to qualified doctors.

Group incompatibility of mother and fetus

Less often, but still there is incompatibility by blood type.

Blood type is a combination of surface antigens (agglutinogens) of erythrocytes of the AB0 system genetically inherited from biological parents.

Each person belongs to a certain blood type according to the AB0 system: A (II), B (III), AB (IV) or 0 (I).

This system is based on a laboratory analysis for the determination of two agglutinogens (A and B) in human blood.

• I blood group - otherwise it is group 0 (“zero”), when neither A nor B agglutinogens were found on red blood cells during a blood test for group affiliation.
• Blood type II is group A, when the erythrocytes contain only A agglutinogens.
• Blood type III is group B, that is, only B agglutinogens were found.
• The IV blood group is the AB group, both A and B antigens are present on erythrocytes.

Group incompatibility is often observed if the future mother has the I blood group, and the future father of the child has the IV-th, then the fetus will inherit the II or III blood group. But there are other options for incompatibility by blood group (see table 2).

Table 2 - The likelihood of developing a conflict in blood type during pregnancy

Usually, group incompatibility proceeds much easier than Rhesus, so the blood type conflict is considered less dangerous, and babies who have had a blood type conflict are born with ordinary jaundice, which soon disappears.

The main danger posed by the Rhesus conflict during pregnancy is the pathology of the blood (hemolysis) of a developing intrauterine or born child. This condition is accompanied by the destruction of red blood cells. It leads to oxygen starvation and intoxication of the child with metabolic products.

Rh factor: what is it?

Blood circulates in human vessels, which consists of a liquid - plasma and cells, most of which are red bodies - erythrocytes. They contain hemoglobin, which carries oxygen and carbon dioxide. There are numerous protein molecules on the surface of erythrocytes. One of them is the Rh0(D) protein, or Rh factor.

This protein appears in the embryo in early pregnancy and is present in 85% of Caucasians who are considered Rh-positive. If Rh0 is absent on erythrocytes, these are Rh-negative patients. In itself, the presence or absence of this protein does not affect human health. However, Rh incompatibility during blood transfusion or pregnancy can cause adverse effects.

When does Rh conflict occur?

This is only possible if the mother does not have the Rh factor, but the fetus does.

The presence of the Rh factor is passed on to the child with genes from his father. In a man, the presence of this protein is controlled by genes located on a pair of chromosomes. The positive Rh factor is controlled by a pair of genes. It appears in two cases:

• Both genes are dominant in the male (DD). This is seen in 45% of males who have a positive Rh. In this case, the child will always be born Rh-positive.
• The male is heterozygous for the Rh factor, that is, one chromosome has a dominant D gene, and the other has a recessive d gene (set Dd). In such a situation, the father will pass on the Rh D positive gene to the child in half the cases. Heterozygous men make up 55%.

Determination of the D and d genes is difficult and is not used in practice. To avoid pathology in the fetus, it is considered by default to be Rh-positive. Although, once again, we note that about a quarter of Rh-positive men have an Rh-negative child, and in this case, incompatibility does not appear, despite the different rhesus of the parents.

The probability of pathology can be predicted in advance only by knowing the set of genes in the father (DD or Dd). It is determined only when necessary. Therefore, it is almost impossible to calculate in advance the possibility of the birth of an Rh-negative baby. With different Rhesus in parents, it can range from 25 to 75%.

The probability of developing incompatibility and Rh-conflict, even with different Rhesus of the mother and fetus, with the right tactics for managing pregnancy, is small. So, during the first pregnancy, pathology develops only in 5% of cases.

How does pathology occur?

In the case when the mother does not have Rh, her body reacts to it as a foreign protein, producing the appropriate antibodies. This reaction is designed to protect the internal environment of a woman from the penetration of genetically alien material. A variety of antibodies are produced in response to any foreign antigen.

Normally, the blood of the mother and fetus practically does not mix during pregnancy, so Rh incompatibility usually does not occur during the first pregnancy. However, such a probability still exists if the bearing of a child is accompanied by pathology of the placenta and an increase in the permeability of its vessels.

How Rh-positive red blood cells enter the blood of an Rh-negative patient:

• during pregnancy, especially if it is accompanied by a threat of miscarriage or serious illnesses of a woman; at the same time, the integrity of the placental vessels is violated, and the fetal blood mixes with the mother's blood;
• with amniocentesis, cordocentesis or chorion biopsy - diagnostic procedures performed during childbearing;
• with, its manual separation, as well as during cesarean section;
• as a result of miscarriage, induced abortion, surgery for ectopic pregnancy;
• in case of transfusion of Rh-positive blood.

In response to the first hit of a foreign protein, IgM class antibodies are synthesized in a woman's body. Their molecule is large and does not enter the bloodstream of the fetus, so there are most often no negative consequences for the baby during the first pregnancy. A slight increase in frequency was noted.

The second pregnancy with a negative Rh in the mother is accompanied by repeated contact of her body with a positive Rh-factor of the fetus. In this case, a large number of much smaller antibodies of the IgG class are rapidly produced. They easily penetrate the vessels of the placenta and cause hemolytic disease in the child.

Antibodies in Rh-negative pregnancy bind to the Rh antigen on the surface of fetal red blood cells. In this case, blood cells are destroyed, their decay products turn into a toxic substance - indirect bilirubin. A decrease in the number of red blood cells leads to anemia, and bilirubin stains the skin, urine and thus causes jaundice.

Anemia (lack of red blood cells, accompanied by oxygen starvation - hypoxia) causes an adaptive reaction - increased formation in the child's body of the hormone erythropoietin, which stimulates hematopoiesis, that is, the formation of red blood cells. This substance acts not only on the bone marrow, which normally synthesizes red blood cells.

Under its influence, extramedullary (outside the bone marrow) foci of erythrocyte synthesis occur in the spleen, kidneys, liver, adrenal glands, fetal intestine and placenta. This is accompanied by a decrease in the lumen of the umbilical and hepatic veins, an increase in pressure in the portal vein system, metabolic disorders and impaired protein synthesis in the liver.

As a result of edema, compression of the smallest vessels occurs - capillaries, in which oxygen, carbon dioxide and metabolic products are exchanged between blood and tissues. There is oxygen starvation. Due to the lack of oxygen, incompletely oxidized ("not burned") metabolic products accumulate, acidification of the internal environment of the body (acidosis) develops. As a result, pronounced changes occur in all organs of the fetus, accompanied by a sharp violation of their functions.

Indirect bilirubin penetrates well into the brain tissue and causes damage to the nerve centers - encephalopathy and kernicterus. As a result, the work of the central nervous system is disturbed in the child: movements, sucking reflex, muscle tone.

So, what is the Rh conflict during pregnancy? This is a state of incompatibility between the child and the mother according to the Rh system, as a result of which the erythrocytes of the fetus are destroyed by antibodies that have come from the mother's blood. Negative consequences for the child are associated with manifestations of hemolytic disease.

How does the Rh factor affect pregnancy?

• For the woman herself, there is no immediate threat; the danger is miscarriage, premature birth and other pathology resulting from hemolytic disease.
• With an Rh-negative fetus, the course of pregnancy is normal, since the mother's body does not react with the Rh factor and does not form protective IgG antibodies.
• If the child is Rh-positive, the mother's body produces antibodies to its protein, and he may develop hemolytic disease.
• The risk of pathology increases with each subsequent pregnancy, which is associated with the accumulation of IgG in the mother's blood.

The well-being of the expectant mother does not change; when she is examined by a doctor, there are also no pathological signs.

In case of incompatibility with the mother's blood according to the Rh factor, the child may experience symptoms of an Rh conflict. They make up the clinical picture of a hemolytic disease that develops in a fetus or a newborn baby. The severity of the manifestations of this pathology can be different - from mild temporary jaundice to a deep disruption of the internal organs and brain.

Hemolytic disease can cause fetal death within 20-30 weeks.

If the fetus continues to develop, increasing anemia and an increase in the content of bilirubin in its blood lead to the appearance of such signs:

• decrease in the number of red blood cells;
• an increase in fetal weight due to swelling of the internal organs and subcutaneous tissue;
• accumulation of fluid in its cavities;
• swelling of the placenta;
• violation of the heart, reflecting a lack of oxygen.

After the birth of a child, due to damage to the nervous system by poisonous bilirubin (nuclear jaundice), the following symptoms appear:

• muscle weakness;
• feeding difficulties;
• regurgitation;
• vomit;
• convulsive syndrome, in particular, opisthotonus - arching with a spasm of the muscles of the arms and hands;
• an increase in the abdomen;
• pallor or yellowness of the skin, conjunctiva of the eyes, lip rims;
• restlessness and constant shrill crying of the baby.

The second or even third pregnancy in a mother with a negative Rh, if all the doctor's recommendations are followed, can end happily. For this, prevention of the Rhesus conflict is necessary. In particular, it is necessary to administer a special drug, immunoglobulin, on time.

If the mother is Rh positive, and the child is Rh negative, then incompatibility does not appear, the pregnancy proceeds normally.

Diagnostics

To recognize the Rh-conflict, a combination of two approaches is used:

• determination of the mother's sensitization, that is, traces of contact between her Rh-negative blood and Rh-positive erythrocytes;
• recognition of hemolytic disease.

Pregnancy with a negative Rh in a woman is dangerous for the development of an Rh-conflict if she has experienced such situations in the past:

• transfusion of Rh-incompatible blood;
• miscarriage;
• artificial abortion;
• intrauterine death of the embryo;
• hemolytic disease of the child.

At what time does the Rhesus conflict occur?

The appearance of this pathology is possible already from 6-8 weeks of intrauterine development, when the corresponding protein appears on the erythrocytes of the fetus. Therefore, in an Rh-negative woman, from the moment of registration in a consultation (6-12 weeks), they begin to regularly determine the content of anti-Rh antibodies. An analysis for the Rh conflict during pregnancy is repeated every month.

The absolute content of antibodies is not significant, because the fetus can be Rh-negative, and then any amount of maternal antibodies will not harm him. Doctors pay attention to an increase in the content of antibodies in the blood - an increase in their titer.

The antibody titer is the highest dilution of maternal blood serum, in which their amount is still determined, sufficient for gluing (agglutination) of erythrocytes. It is expressed by the ratio 1:2, 1:4, 1:8 and so on. The larger the second number in this ratio, the higher the concentration of IgG immunoglobulins.

The antibody titer during childbearing may decrease, increase or not change. Its sharp increase or abrupt change is dangerous.

Can the Rh factor change during pregnancy?

No, since the presence or absence of this protein is genetically mediated, inherited and does not change throughout life.

Ultrasound examination (ultrasound) of the fetus and placenta is used to diagnose hemolytic disease. The first signs of this pathology are visible, starting from 18-20 weeks. Then ultrasound is performed at 24, 30, 36 weeks and before delivery. In severe cases, the time between studies is reduced to 1-2 weeks, and sometimes ultrasound must be performed every 3 days or even more often.

The negative effect of ultrasound on the fetus has not been proven, but the consequences of an unrecognized hemolytic disease can be sad. Therefore, you should not refuse to re-examine, because this will help save the life and health of the child, and in some cases, the mother.

What is dangerous Rh-conflict during pregnancy according to ultrasound:

• thickening of the placenta, accompanied by a violation of the blood flow in it and a deterioration in the nutrition of the fetus;
• enlargement of the liver and spleen;
• and developmental anomalies;
• accumulation of fluid in the fetal peritoneal cavity (ascites), in the pleural cavity (hydrothorax) and around the heart (pericardial effusion);
• enlargement of the heart (cardiomegaly);
• swelling of the intestinal wall and subcutaneous tissue.

They also study the content of bilirubin in the amniotic fluid, which helps to assess the intensity of the breakdown of red blood cells. For this, spectrophotometry is used from week 24, and photoelectrocolorimetry (FEC) is used from week 34.

The study of amniotic fluid (amniocentesis) is prescribed in such situations:

• fetal death from hemolytic disease in a previous pregnancy;
• severe hemolytic disease of the newborn in a previous birth, requiring a blood transfusion;
• Ultrasound signs of Rh conflict in the fetus;
• antibody titer 1:16 and above.

- an invasive procedure that includes a puncture of the fetal bladder and the collection of amniotic fluid for analysis. It increases the risk of Rh-conflict, as it can be accompanied by blood contact between a woman and her child. Therefore, in recent years it has been used less and less.

To narrow the indications for this study, ultrasound determines the speed of blood flow in the middle cerebral artery of the fetus. It has been proven that the higher this indicator, the lower the hemoglobin level in the child and the greater the likelihood of hemolytic disease. If blood flow is close to normal, amniocentesis may not be performed. However, the question of the need for the procedure should be decided taking into account all other data on the health of the woman and the developing child.

The most accurate method for diagnosing Rhesus conflict is the study of cord blood, or cordocentesis. It is carried out from 24 weeks and is prescribed in such cases:

• high density of bilirubin according to spectrophotometry (2C or 3);
• Ultrasound signs of hemolytic disease;
• antibody titer 1:32 or more;
• pathology of a previous pregnancy (see indications for amniocentesis).

In umbilical cord blood, the group, Rhesus, hemoglobin, red blood cells, bilirubin are determined. If the fetus is Rh-negative, hemolytic disease is impossible. Further observation of the woman is carried out as a healthy pregnant woman.

If the fetal blood is Rh-positive, but the hemoglobin content and hematocrit are within the normal range, a second cordocentesis is performed after a month. With poor analyzes, intrauterine treatment begins.

To diagnose oxygen starvation of a child, a repeated cardiotocography is performed - a study of the heartbeat.

Therapy

In mild cases, treatment is aimed at strengthening the vessels of the placenta, preventing oxygen starvation of the child and maintaining pregnancy. A woman is put on a special account, her state of health is constantly monitored by an obstetrician-gynecologist.

Fortifying agents, vitamins, vascular preparations are prescribed. If necessary, hormones that preserve the developing fetus (gestagens) are used.

If hemolytic disease is diagnosed, treatment of the Rh conflict during pregnancy begins. When the life of the child is threatened, intrauterine blood transfusion is performed. The positive impact of this procedure is very noticeable:

• the level of hemoglobin and hematocrit in the blood of the child increases;
• reduces the likelihood of the most severe form of hemolytic disease - edematous;
• the preservation of pregnancy is ensured;
• transfusion of washed erythrocytes weakens the immune response of the mother's body and the severity of the Rhesus conflict.

Before intrauterine transfusion, cordocentesis is performed and the hemoglobin content is analyzed. If it was possible to determine the blood type of the fetus, the same is transfused. If such a determination fails, 1 blood group Rh negative is used. Depending on the gestational age and laboratory parameters, the required volume is determined and slowly injected into the umbilical cord. Then do a control blood test.

This procedure is usually carried out in a period of more than 22 weeks. If it is necessary to transfuse at an earlier date, blood can be injected into the abdominal cavity of the fetus, but the effectiveness of this method is lower.

Intrauterine transfusion should be performed in a well-equipped hospital. It can cause various complications, up to bleeding and death of the fetus. Therefore, the procedure is carried out only when the risk of pathology of the child due to hemolytic disease exceeds the likelihood of complications. Any questions about this should be discussed with your doctor.

It is believed that the hematocrit in severe hemolytic disease is reduced by 1% every day. Thus, the need for a second procedure occurs after 2-3 weeks. Repeated transfusions in severe cases can be performed several times until the period of 32-34 weeks, after which delivery is performed.

Plasmapheresis or immunosorption can also be used. These are methods of cleaning the mother's blood from anti-Rhesus antibodies using special filters that trap these immunoglobulins. As a result, the concentration of IgG against the Rh factor in the woman's blood decreases, the severity of the conflict decreases. These methods are related to extracorporeal detoxification and require modern equipment and qualified personnel.

Birth tactics:

• in a period of more than 36 weeks, with a prepared birth canal and a mild course of hemolytic disease, natural childbirth is possible;
• with a severe form of the disease, it is better to carry out in order to avoid additional risk to the child.

The consequences of the Rh conflict during pregnancy include anemia, fetal jaundice, swelling of the skin and internal organs. For treatment, transfusion of blood, plasma, erythrocytes, detoxification, phototherapy is used. Breastfeeding begins after the child's condition improves, usually 4-5 days after birth. Antibodies contained in breast milk do not enter the baby's bloodstream and are not dangerous to him.

Rh incompatibility warning

Prevention of Rh conflict during pregnancy includes:

• blood transfusion only taking into account compatibility by group and Rh factor;
• preservation of the first pregnancy in an Rh-negative woman;
• Rh-prophylaxis in a Rh-negative patient after any termination of pregnancy (miscarriage, abortion, childbirth);
• Rh prophylaxis in Rh-negative pregnant women without signs of sensitization.

If the patient is Rh negative and she has not yet experienced sensitization, that is, there has not been contact with fetal red blood cells, and therefore there are no antibodies in the blood (for example, during the first pregnancy), she needs prophylactic administration of specific antibodies.

Immunoglobulin with a negative Rh during pregnancy is a special protein that, when it enters the woman's blood, binds her antibodies, which can be formed upon contact with Rh-positive red blood cells, that is, during sensitization. If it does not happen, the injected immunoglobulin will not work, since the patient's body will not begin to produce its own IgM and IgG. If sensitization still appears, the "vaccine" with a negative Rh inactivates maternal antibodies that are dangerous to the fetus.

If during the initial determination and subsequently antibodies do not appear in a woman, at 28 weeks, with a negative Rh, a “vaccination” is done. Later, fetal erythrocytes can already penetrate the maternal blood and cause an immune response, so the introduction of immunoglobulin in a longer period is not so effective.

At 28 weeks, if the father has a positive Rh (that is, when there is a possibility of an Rh conflict), 300 μg of a specially developed drug, anti-Rh0 (D) -immunoglobulin HyperROU S / D, is administered. It does not cross the placenta and does not affect the fetus. The introduction is repeated after any invasive procedure (amniocentesis, cordocentesis, chorionic biopsy), as well as in the first 3 days (best in the first 2 hours) after the birth of an Rh-positive child. If a baby with a negative Rh was born, there is no threat of sensitization of the mother, and in this case, immunoglobulin is not administered.

If during childbirth a manual separation of the placenta was performed or there was a detachment, as well as after a cesarean, the dose of the drug is increased to 600 mcg. It is administered intramuscularly.

At the next pregnancy, if antibodies in the blood have not appeared, the prophylactic administration of immunoglobulin is repeated.

Immunoglobulin does not destroy fetal red blood cells, as can sometimes be read. It is not directed against the Rh protein, but against the protein of maternal anti-Rh antibodies. With the Rh factor itself, located on the surface of red blood cells, prophylactic immunoglobulin does not react in any way.

Prophylactic immunoglobulin is not an anti-Rhesus antibody. After its introduction, antibodies to Rh in the mother's blood should not appear, because it is intended precisely to prevent their production. On numerous sites devoted to this topic, a lot of conflicting unprofessional information. All questions regarding antibodies and prophylactic immunoglobulin should be checked with a doctor.

Negative Rh factor during pregnancy is not a sentence for a woman. Even if she already has sensitization, and the first children were born with severe hemolytic disease, she can give birth to a healthy baby. There is one condition for this: the father of the child must be heterozygous for the Rh factor, that is, have a set of genes not DD, but Dd. In this case, half of his sperm can give the baby a negative Rh.

For the onset of such a pregnancy, in vitro fertilization is required. After the formation of embryos, only those that have inherited a negative Rh from both mother and father are used for implantation in the uterus. In this case, the Rh conflict does not appear, the pregnancy proceeds normally and a healthy child is born.

It is necessary to remember the need for a thorough diagnosis before blood transfusion. An Rh-negative woman should only be transfused with Rh-negative blood, preferably of the same group. If this is not possible, a blood type compatibility table is used:

Women with the first blood group are allowed to transfuse only the same. Patients from the fourth - blood of any group. If there is blood of group II or III, compatibility must be clarified according to the table.

In no case should the concept of the possibility of a blood transfusion be extended to the compatibility of a married couple! People with any group affiliation can have healthy children, since the red blood cells of the mother and father never mix with each other. The conflict between the blood type of a woman and her child is also almost impossible.

If the father of the child has a positive Rh factor, and the mother has a negative Rh factor, it is necessary to register on time when pregnancy occurs and follow all the doctor's prescriptions:

• regularly do an analysis to determine anti-Rhesus antibodies;
• time to do an ultrasound of the fetus;
• if antibodies are not found in the blood, prophylactic administration of immunoglobulin;
• agree to these procedures if an amniocentesis or cordocentesis is required.

If these conditions are met during the first and subsequent pregnancies, the likelihood of Rh incompatibility and hemolytic disease is significantly reduced.

What does the concept of Rh-conflict mean - this is a special protein that is located on the surface of red blood cells. All people have it, except for 15% of the inhabitants of the planet. Therefore, most of them are called Rh-positive, the rest - Rh-negative.

The Rh factor is an immunological quality of blood that does not affect health at all. Only Rh-positive blood is considered stronger.

Blood conflict between mother and child during pregnancy

Rhesus conflict during pregnancy appears when a positive Rh is found in the father, then most likely the child will also have Rp +. In this case, a Rhesus conflict is possible.

It is possible to establish Rp in a baby in a safe way only approximately, based on the coefficients of the parents.

Rhesus conflict occurs infrequently - in only 0.8% of cases. However, this can have serious consequences. Why? A positive Rp baby for a mother with negative blood is a serious danger. In order to cope with it, antibodies begin to be produced in the female body, which react with the child's red blood cells and destroy them. This action is called hemolysis. In the space between the placenta and the uterus, the blood of the mother and child meets. And here an exchange happens: oxygen and vital components enter the blood of the fetus, and the products of its vital activity enter the mother's body. At the same time, part of the erythrocytes also change places, as a result of which the positive cells of the fetus enter the mother's blood, her erythrocytes, and hence the antibodies, enter the child's blood.

During the second pregnancy, the occurrence of a Rh conflict is much more likely, because the woman's body, already in contact with Rh-negative blood cells for the second time, begins to produce other antibodies - lgG. They freely enter the body of the child through the placenta. As a result, hemolysis continues there, the product of the breakdown of hemoglobin, the toxin bilirubin, accumulates in the body.

Table of Rh-conflict by blood type during pregnancy and inheritance by a child

What is dangerous Rhesus conflict?

Symptoms

There are three forms of the disease: icteric, edematous, anemic.

Edema is the most severe and dangerous for the baby. After giving birth, they often end up in intensive care. In the icteric form, the amount of bilirubin in the amniotic fluid is determined. The anemic form is the mildest.

How to determine the presence of Rhesus conflict

Fetal damage: how to determine its degree?

With the help of the dopplerometry procedure, cardiac activity is assessed, it is determined at what speed the blood flow moves in the blood vessels of the placenta and the baby.

With the help of CTG, the degree of reactivity of the cardiovascular system and the presence of hypoxia are determined.

There are two invasive ways to assess fetal position. Amniocynthosis - when the amniotic sac is pierced and the amniotic fluid is taken for analysis. This allows you to set the measure of bilirubin, and at the same time - very accurately assess the condition of the fetus.

Cordocentosis - when the umbilical cord is pierced and blood is taken for analysis. This method is even more accurate. With its help, a blood transfusion is done to the fetus.
Like amniocentesis, this method is quite unsafe. It also leads to complications, causes the risk of developing a hematoma on the umbilical cord.

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