Do you know which Rh factor prevails in people of the European race? How important is it when planning a child? And what does this concept actually mean? You will find answers to these and other questions in our article.
Composition of blood
Among all the fluids that make up the internal environment of the body, it is the blood that provides gas exchange, cell nutrition, immunity formation and thermoregulation. Providing such important functions is possible due to its composition. Blood consists of intercellular substance - plasma - and formed elements. These include erythrocytes, leukocytes and platelets. As a result, a kind of "transport system" is formed. Each element in it performs its functions. So, plasma plays the role of intercellular substance, leukocytes provide immunity, and platelets - coagulation.
Red blood cells
Erythrocytes carry oxygen from the lungs to the cells, and carbon dioxide in the opposite direction. Their red color is due to hemoglobin. This substance consists of the protein globin and the iron-containing component - heme. The latter contains iron. It is its atoms that not only give erythrocytes a red color,but they also transport gas molecules.
What is the Rh factor
There may be a special protein on the erythrocyte membrane. This is the Rh factor. It is present in 86% of the world's population. Such people are called Rh-positive. And 14% don't have it. They are called Rh-negative.
This sign underlies one of the 36 blood group systems. The most common of these is ABO. These are the four main blood groups. They were discovered back in 1901 by the Austrian scientist Karl Landsteinr, for which he was awarded the Nobel Prize. But transfusiologists - scientists who transfuse blood - consider the Rh system to be clinically more important. It consists of 54 antigens. The term "Rh factor" refers to only one of them. This is antigen D.
Statistics
Scientists say that Rh is a sign that depends on race and geography of residence. For example, 85% of Caucasians, 93% of Negroids, and 99% of Asians and Indians have it. The nature of the influence of this trait on nationalities has not yet been established. In any case, the presence of Rh is inherited, does not depend on blood type and does not change throughout life.
A bit of history
Rhesus is a sign that was also discovered by Karl Landsteinr. But this happened much later than the first sensation - in 1940. Together with the American immunohematologist Alexander Wiener, the scientist for the first timefound this protein in the blood of macaques, a type of which is called Rhesus. It was a previously unknown agglutinogen - antigen D. It was not included in the ABO blood group system.
Rhesus monkey erythrocytes were added to the blood of rabbits during research. The result was a special kind of serum. When mixed with human blood of different groups, in 85% of cases, erythrocytes stick together. This serum is called Rh-positive.
Factor definition
Knowledge of one's own Rh is necessary in two cases. This is blood transfusion and family planning. To find out the Rh factor of a person, it is necessary to take capillary or venous blood for analysis. This should be done in the morning, on an empty stomach. The day before, it will be necessary to exclude fatty foods, drugs and alcohol from the diet.
The most common way to determine Rhesus is by gluing red blood cells in a Petri dish. For this, two drops of blood and serum are placed in it. Next, they are connected with a glass rod and the resulting mixture is heated on a steam bath for 10 minutes. If red flakes appear at the same time, it means that the erythrocytes have stuck together. This indicates a positive Rh factor.
Blood transfusion rules
By 1873, there were 247 transfusions, of which 176 were fatal. Only the discovery of blood groups made it possible to determine what needs to be considered during this process. Not all of them are compatible. When transfused, there should be no sticking or agglutination,erythrocytes.
In the ABO system, the first group is universal. Its owners are considered universal donors. It does not contain adhesive substances called "agglutinogens". People with the fourth blood group are universal recipients. Theoretically, they can be transfused with the blood of all other groups.
And what Rhesus should be in order for the blood transfusion to be successful? It all depends on the "donor-recipient" system. An Rh-positive person can be given blood without this protein. Otherwise, agglutination will occur. The fact is that if a person has no Rhesus to the blood, his hit is perceived by the body as a foreign attack and a protective reaction begins - aggregation of erythrocytes.
Rhesus compatibility
Let's find out what it is. Of particular importance is the Rh blood of parents. There is an opinion that it affects the possibility of conception, the course of pregnancy and the he alth of the unborn child. Not all of this is true. First of all, you need to know that neither the blood type nor the Rh factor affect the fertilization process. Other causes of infertility should be looked for. It has been proven that parents with different Rh factors may well have he althy children.
But this symptom can significantly affect the course of pregnancy. Which Rhesus combination can pose a threat? Imagine that an Rh-negative woman is carrying an Rh-positive child. When the blood of the fetus enters the mother's body, the latter begins to defend itself - to produce antibodies. These are specific proteins that are formed in response toforeign substances - antigens. Protecting itself in this way, the mother's body endangers the life of the unborn child: intrauterine death or miscarriage can occur at any stage of pregnancy.
When Rh conflict occurs
When planning a family, you need to pay attention to a few simple points. First of all, future parents must be tested for Rh. If it is positive or negative in both cases, there is no reason to worry. A conflict can only arise if antigen D is not found in the mother's blood, but the father has it.
In this case, the mother's immune response is inevitable. Even in the normal course of pregnancy, the Rh factor of the fetus overcomes the placental barrier. In response, antibodies form in the mother's blood. Through the placenta, they penetrate into the fetus, destroying its red blood cells. Anemia develops over time.
Bilirubin is formed in the baby's blood, which leads to the development of jaundice. It is this substance that gives the child's skin a yellow tint. The result of the Rh conflict can also be damage to the nervous system, swelling and even death of the fetus.
Mixing the blood of a mother and an unborn child can also occur in case of unforeseen situations. It could be an ectopic pregnancy, vaginal bleeding, or mechanical trauma to the abdomen.
Advances in modern medicine
But don't panic. Currently, a whole system of preventive measures has been created that can avoid the Rhesus conflict. Withthe first days of pregnancy, the situation must be kept under strict control.
Expectant mother should regularly donate blood for analysis. Until the 32nd week, it will be enough to do this once a month. Further, the likelihood of developing antibodies increases. Therefore, from the 32nd to the 35th week, the blood is checked 2 times a month, and then every week. If antibodies are not detected, anti-Rhesus gamma globulin is administered to the expectant mother. This vaccine prevents their formation. This vaccine is effective for a period of 18 to 20 weeks. In the same period, the first ultrasound is performed. Based on its results, it is already possible to determine whether the fetus develops hemolytic disease. Its signs will be a thickening of the placenta, as well as an enlargement of the spleen and liver.
If the mother's blood test shows a slight appearance of antibodies, then she is prescribed outpatient treatment. It is aimed at reducing the body's response to antigens. Such desensitizing drugs are solutions of glucose, vitamins or ascorbic acid.
When the level of antibodies reaches a critical level, urgent hospitalization and constant monitoring of the condition of the expectant mother and child are necessary. In this case, a dangerous signal is the appearance of fluid in the fetus in the pericardial sac and abdominal cavity.
To clarify the picture, amniotic fluid is analyzed for bilirubin content. If it is elevated, there are several ways out of the situation. The simplest is the purification of the mother's plasma from antibodies - plasmapheresis. Blood transfusion to the fetus will also be effective. This procedure must be carried out under ultrasound guidance. fetusRh-negative blood is injected through the umbilical vein, which temporarily replaces his own. This procedure is repeated every two weeks.
When pregnancy is accompanied by Rh conflict, the most important thing is to bring it to 34 weeks. During this period, the fetal organ systems are already sufficiently formed and we can talk about early birth.
Second pregnancy
After the first birth, antibodies remain in the blood of an Rh-negative mother. This can make future pregnancies much more difficult. The presence of antibodies increases the likelihood of Rh conflict.
To avoid this, within a day after the first birth, a drug is injected into the mother's blood. It's called anti-Rhesus immunoglobulin. The drug prevents the formation of antibodies, reducing the risk of further complications.
So, Rh-affiliation is determined by the presence of a special protein on the erythrocyte membrane. It is found in the blood of most people. They are called Rh-positive. This symptom must be considered during blood transfusion and pregnancy. If Rh enters the blood, which does not contain this protein, the destruction of red blood cells occurs. Existing medical measures allow in most cases to avoid Rh conflict.
