Rhesus conflict during pregnancy - Causes, symptoms and treatment. MF.

According to the definition, Rh Rhinitisation( Rh Sensitization / Rh Conflict) is the occurrence of a pregnant Rh factor of antibodies in response to ingestion of fetal erythrocyte antigens into the bloodstream, ie, paraphrasing is easier - is the incompatibility of a mother with a Rh negative-blood group with a child, having a rhesus positive blood group( and not with her husband, as many think).

Rhesus antigen is a protein found in the membrane of red blood cells / red blood cells of most people. The blood of such people is positive for the Rh system, and the blood of those who do not have this protein, respectively, is called Rh-negative. About 1/3 of the population is Rh-negative.

Rh-negative parents may well have a Rh-negative child. In this case, a very peaceful, conflict-free relationship develops between a "positive" mother and her "negative" child: this combination does not threaten neither the woman nor the fetus.

If the mother and father have a Rh-negative baby, the child also has a negative Rh factor.

But with the presence of Rh-negative blood in the mother, and the father's positive, Rh-positive fetus occurs in 60% of pregnant women, but only 1.5% of these pregnancies develop incompatibility.

As a rule, with a repeat pregnancy, the incidence of incompatibility is higher than the first.

Mechanism of rhesus-conflict development

If Rh-positive red blood cells occur with Rh-negative, then they coalesce - agglutination. To prevent this from happening, the immune system of the Rh-negative mother produces special proteins-antibodies that bind to Rhabel in the membrane of the fetal erythrocytes( antigens), preventing them from sticking to their own erythrocytes of the mother. Antibodies are called immunoglobulins and come in two forms: IgM and IgG.

Contact of the fetal red blood cells with antibodies occurs in the space between the uterus wall and the placenta. At the first meeting of fruit Rh-positive erythrocytes with the immune system of the Rh-negative mother, production of IgM occurs, the size of which is too large to penetrate the placental barrier. That is why, as a rule, during the first pregnancy of the Rh-negative mother with a Rh-positive fetus, the conflict arises comparatively rarely. Incompatibility develops with the re-entry of fetal antigens( Rh positive red blood cells) into the bloodstream of the Rh-negative mother, whose immune system then generates IgG, which, having smaller dimensions, penetrate the placenta and cause hemolysis, i.e.destruction of red blood cells of the fetus. This is how the hemolytic disease of the fetus / newborn develops.

Complications of Rhesus Conflict

As a result of the destruction of erythrocytes, almost all organs and systems of the fetus are toxicly affected by the product of the decomposition of hemoglobin, a substance found in red blood cells and responsible for the transport of oxygen. This is due to the product of decay - bilirubin. First of all, the central nervous system of the fetus, the liver, kidneys and heart is affected, fluid accumulates in the cavities and tissues, which interferes with the normal functioning of organs and systems right up to intrauterine death in severe cases. It is in connection with this "rejection" of the fetus that Rh-negative mothers often develop a threat of miscarriage, and the risk of intrauterine fetal death increases.

Rhesus Risk Factors

Are divided into:
1. Pregnant:
- any type of abortion: miscarriage, instrumental and medical abortion;
- ectopic pregnancy;
- delivery, namely, in the third period, when there is separation of the placenta from the uterine wall;
- complication of pregnancy or childbirth - premature detachment of the placenta, which is accompanied by bleeding from the vessels of the placenta;
- any invasive methods of investigation:( amniocentesis, cordocentesis - puncture of the bladder or umbilical cord).
2. Unrelated to pregnancy:
- immunization with blood transfusion;
- use of one needle for intravenous drug use.

Symptoms of Rh-conflict

There are no clinical manifestations in the patient, her condition does not suffer.

Symptoms of hemolytic disease in the fetus during pregnancy can be detected only with ultrasound, they are: swelling, accumulation of fluid in the cavities( abdominal, thoracic, in the cavity of the pericardial bag);due to the accumulation of fluid in the abdominal cavity of the fetus, the size of the tummy increases, the fetus takes a definite position "Buddha's posture"( when, unlike the norm, the limbs are diverted from the enlarged abdomen), an increase in the size of the liver and spleen, an increase in the size of the heart, a "double" contour appearshead( as a result of edema of the soft tissues of the head).Also, the edema and, accordingly, the thickening of the placenta and the increase in the diameter of the vein of the umbilical cord are determined. Depending on the prevalence of this or that sign, three forms of hemolytic disease of the fetus are distinguished: edematous, icteric and anemic.

Rhesus conflict diagnosis and pregnancy management tactics

The aim of monitoring pregnant women with Rhesus immunization is the following: examination to detect sensitization, prophylaxis of Rhesus immunization, early diagnosis of hemolytic disease of the fetus and its correction, and determination of the most optimal timing for delivery. At registration on the account on pregnancy the definition of a blood group, both the pregnant woman, and the father of the child in the planned order is shown. In the presence of Rh-negative blood from the mother and Rh-positive blood from the father, the pregnant women are tested for antibodies 1 once a month, monitoring the dynamics of the antibody titer. In the presence of any antibody titer, pregnancy is considered a rhesus sensitized. If antibodies are detected for the first time, then their class( IgM or IgG) is determined. Then the blood test for antibodies is carried out monthly, observing the patient for up to 20 weeks in the women's consultation, and after 20 weeks - sent to specialized centers to determine the further tactics of conducting, possibly, treatment and decide on the method and timing of delivery.

Since 18 weeks, the evaluation of the condition of the fetus using ultrasound.

Fetal assessment methods are divided into:

1. Non-invasive methods.
- ultrasound, in which assess: the size of the fetal organs, the presence of free fluid in the cavities, the presence of puffiness, the thickness of the placenta and the diameter of the umbilical vein. The first ultrasound is performed in the period of 18-20 weeks, repeated at 24-26 weeks, 30-32 weeks, 34-36 and immediately before delivery. Depending on the severity of the condition of the fetus, this study can be carried out more often, up to the daily( as, for example, after the blood transfusion is given to the fetus).
- dopplerometry, which assesses the functional parameters of the heart, the velocity of blood flow in large vessels of the fetus and the umbilical cord, etc.
- cardiotocography assesses the reactivity of the fetal cardiovascular system, reveals the presence or absence of hypoxia( lack of oxygen).

2. Invasive:
- amniocentesis - puncture of the bladder for the purpose of collecting amniotic fluid to assess the severity of hemolysis from the content of bilirubin( the product of hemoglobin degradation), which is one of the most accurate methods for assessing the severity of the fetal condition. Unfortunately, this method is fraught with many complications: infection, prenatal discharge of amniotic fluid, premature birth, bleeding, premature detachment of the placenta. Indications for amniocentesis: antibodies titer of 1:16 and more, the presence of children who underwent a severe form of hemolytic disease of newborns.
- cordocentesis - puncture of the umbilical cord with the purpose of blood sampling. The method makes it possible to accurately assess the severity of hemolysis, to carry out intrauterine fetal blood transfusion simultaneously. In addition to those complications that are typical for amniocentesis, the development of umbilical cord hematoma and bleeding from the puncture site is also possible during cordocentesis. The evidence for cordocentesis is the determination of signs of hemolytic disease of the fetus with ultrasound, antibody titer of 1:32 and above, the presence of children who have had severeform of GBP in the past or died from it, a high level of bilirubin in the amniotic fluid obtained during amniocentesis.

In connection with the possible risk, before carrying out both procedures, the patient should be informed by the doctor about the possibility of adverse consequences of the procedure and give her written consent for its conduct.

Treatment of Rhesus Conflict

In modern obstetrics, the only treatment with proven efficacy is intrauterine blood transfusion, which is performed with severe anemia( anemia) in the fetus. This kind of treatment is carried out only in the hospital and allows to achieve a significant improvement in the fetus and reduce the risk of premature birth and the development of severe disease after birth.

Patients of a high risk group( in whom the antibody titer is detected in the early stages, those with an antibody titer of 1:16 and above, those who had a previous pregnancy with a rhesus conflict) are observed under the conditions of a female consultation for up to 20 weeks, and then sent toSpecialized hospitals for the above treatment.

Various methods for purifying the mother's blood from antibodies( plasmapheresis, hemosorption), methods that affect the activity of the immune system( desensitizing therapy, immunoglobulin therapy, patient's transplantation of a child's skin flap) are currently considered ineffective or even ineffective.

But, unfortunately, despite significant successes in the field of correction of the fetal condition, the most effective way is to stop the receipt of maternal antibodies to it, which can be achieved only by delivery.

Rh delivery in rhesus-conflict

Unfortunately, with Rh-sensitization, it is often necessary to carry out the delivery before the end of the day.in late pregnancy there is an increase in the number of antibodies that enter the fetus.
Depending on the condition of the fetus and the gestational age, the method of delivery is individual in each individual case. It is believed that the cesarean section is more sparing for the fetus, in connection with which in severe cases resorted to it. With a satisfactory condition of the fetus, gestation period of more than 36 weeks, the mating is possible to conduct labor through natural birth canals with careful monitoring of the fetus, prevention of intrauterine hypoxia. If his condition worsens in childbirth, the management plan may be revised in favor of a caesarean section.

Forecast for Rh Rhythmic Conflict

The prognosis depends on how early the rhesus immunization was diagnosed, on the antibody titer and rate of increase, and on the form of hemolytic disease of the fetus. The earlier antibodies are found in the mother's blood, for example, at a period of 8-10 weeks, the more prognostically unfavorable it is. Rapid growth of antibody titer, a titer above 1:16, early detection of it( at terms less than 20 weeks) is the basis for an unfavorable prognosis. In such cases, not only the risk of hemolytic disease of the fetus increases, but also the risk of miscarriage.

The most prognostically unfavorable form of hemolytic disease of the fetus is edema. Such children often require treatment in conditions of separation of children's resuscitation and intensive care, replacement of blood transfusion. The most prognostically favorable form is the anemic form,( depending on the severity of the anemia).With icteric form, the determining criterion is the level of bilirubin. The higher it is, the higher the possibility of damaging the central nervous system of the fetus, which manifests itself in dementia and deafness in the future.

Rhesus Conflict Prevention

At present, human antirezus immunoglobulin D is used to prevent rhesus sensitization. This drug has proven effectiveness and exists under several trade names, such as HyperRow C / D( USA), Resonative( France), antiresusive immunoglobulin D( Russia).

Prevention should be carried out during pregnancy at a period of 28 weeks in the absence of antibodies in the mother's blood, as it is at this time that the risk of contact between the mother's antibodies and the erythrocytes of the fetus increases, and the risk of hemolytic disease of the fetus also increases. Due to the administration of the drug, the antibody titre may appear in the blood, so after the administration of the drug, the determination of antibodies is no longer carried out. Next, repeat prophylaxis within 72 hours after delivery if the patient is planning the next pregnancy. If bleeding occurs during pregnancy, as well as during cordo-or amniocentesis, and also in the puerperium, immunoglobulin should be repeated, since the immunoglobulin should be repeated. Rhesus sensitization may occur in the next pregnancy in response to fetal blood( in case of bleeding from the blood vessels of the placenta) into the bloodstream of the mother.

Also, should be prevented by injection of the drug in any outcome of pregnancy: miscarriage, drug or instrumental abortion, ectopic pregnancy, bladder skidding within 72 hours after the interruption. Particular attention is paid to blood loss, when the appearance of which the dose of the drug should be increased.

Doctor obstetrician-gynecologist Kondrashova DV