Do you know what Rh factor prevails among people of the European race? What does it matter when planning a child? And what does this concept mean? You will find answers to these and other questions in our article.
Blood composition
Among all the fluids that make up the body’s internal environment, it is blood that provides gas exchange, cell nutrition, immunity formation and thermoregulation. The provision of such important functions is possible due to its composition. Blood consists of intercellular substance - plasma - and uniform elements. These include red blood cells, white blood cells 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, white blood cells provide immunity, and platelets - coagulation.
Red blood cells
Red blood cells 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 a globin protein and an iron-containing component - heme. The latter contains iron. It is its atoms that not only give red blood cells a red color, but also transport gas molecules.
What is the Rh factor
A special protein may be on the erythrocyte membrane. This is the Rhesus factor. 86% of the world's population have it. Such people are called Rh-positive. And 14% do not have it. They are called Rh-negative.
This feature underlies one of the 36 blood group systems. The most common of these is ABO. These are the four main blood types. They were discovered back in 1901 by the Austrian scientist Karl Landsteiner, for which he was awarded the Nobel Prize. But t- transfusiologists - scientists who deal with blood transfusion - find the Rh system to be clinically more important. It consists of 54 antigens. The term "Rhesus factor" refers to only one of them. This is D. antigen.
Statistics
Scientists claim that rhesus is a sign that depends on race and geography. For example, 85% of Caucasians have it, 93% of Negroids and 99% of Asians and Indians. The nature of the influence of this trait on nationalities has not yet been established. In any case, the presence of Rhesus is inherited, does not depend on the blood group and does not change throughout life.
A bit of history
Rhesus is a sign that was also discovered by Karl Landsteiner. But this happened much later than the first sensation - in 1940. Together with the American immunohematologist Alexander Wiener, the scientist first discovered this protein in the blood of macaques, a species called Rhesus. It was a previously unknown agglutinogen - antigen D. It did not enter the ABO blood group system.
In the course of research, red blood cells of rhesus monkeys were added to the blood of rabbits. As a result, a special type of serum was obtained. When it was mixed with human blood of different groups in 85% of cases, gluing of red blood cells occurred. This serum is called Rh-positive.
Factor Definition
Knowledge of your own Rhesus is necessary in two cases. This is a 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 must be done in the morning, on an empty stomach. The day before this, 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. Then they are connected with a glass rod and the resulting mixture is heated in a steam bath for 10 minutes. If red flakes appear at the same time, then the red blood cells have stuck together. This indicates a positive Rhesus factor.
Blood Transfusion Rules
By 1873, 247 transfusions were made, of which 176 were fatal. Only the discovery of blood groups allowed us to determine what should be taken into account during this process. Not all of them are compatible. When transfusion, gluing, or agglutination, of red blood cells should not occur.
In the ABO system, the first group is universal. Its owners are considered universal donors. It lacks adhesives called “agglutinogens”. People with the fourth blood group are universal recipients. Theoretically, they can transfuse the blood of all other groups.
And what rhesus must be in order for a blood transfusion to be successful? It all depends on the donor-recipient system. A Rh-positive person can receive 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 - the red blood cells stick together.
Rhesus compatibility
Let's find out what it is. Of particular importance is the rhesus blood of the parents. There is an opinion that it affects the possibility of conception, the course of pregnancy and the health of the unborn child. Not all of this is true. First of all, you need to know that neither the blood group, nor the Rh factor have an effect on the fertilization process. Other causes of infertility should be sought. It is proved that parents with different Rh factors may well have healthy children.
But this symptom can significantly affect the course of pregnancy. Which rhesus combination can be a threat? Imagine that a Rh-negative woman has a Rh-positive baby. When the fetal blood enters the mother's body, the latter begins to defend itself - to produce antibodies. These are specific proteins that are formed in response to foreign substances - antigens. Defending itself in this way, the mother’s body threatens the life of the unborn child: intrauterine death or miscarriage can occur at any stage of pregnancy.
When rhesus conflict occurs
When planning a family, you need to pay attention to a few simple points. First of all, expectant parents must undergo a rhesus test. If in both cases it is positive or negative, there is no reason for unrest. A conflict can arise only if antigen D is not detected in the mother’s blood, and the father has it.
In this case, the immune response of the mother’s body is inevitable. Even with a normal pregnancy, the Rh factor of the fetus overcomes the placental barrier. In response, antibodies are formed in the mother’s blood. Through the placenta, they penetrate the fetus, destroying its red blood cells. Over time, anemia occurs.
Bilirubin is formed in the blood of the child, which leads to the development of jaundice. It is this substance that gives the baby's skin a yellow tint. The result of the Rh conflict can also be damage to the nervous system, edema and even death of the fetus.
Mixing the blood of the mother and the unborn baby can occur in case of unforeseen situations. This may be an ectopic pregnancy, vaginal bleeding, or mechanical trauma to the abdomen.
Advances in modern medicine
But do not panic. Currently, a whole system of preventive measures has been created that can avoid Rhesus conflict. From the first days of pregnancy, the situation must be kept under strict control.
The expectant mother should regularly donate blood for analysis. Until the 32nd week, it will be enough to do this once a month. Further, the probability of producing antibodies increases. Therefore, from the 32nd to the 35th week, blood is checked 2 times a month, and then every week. If antibodies are not found, the anticipated mother is given anti-rhesus gammaglobulin. 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. According to its results, it is already possible to determine whether the fetus develops a hemolytic disease. Its signs will be a thickening of the placenta, as well as an increase in 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 antibody level reaches a critical level, urgent hospitalization and constant monitoring of the condition of the future 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, carry out an analysis of amniotic fluid for bilirubin content. If it is increased, 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 is necessarily carried out under the supervision of an ultrasound scan. Rhesus-negative blood is injected into the fetus through the umbilical vein, which temporarily replaces its own. This procedure is repeated every two weeks.
When pregnancy is accompanied by a Rh conflict, the most important thing is to bring it to 34 weeks. During this period, the system of the fetal organs is already quite formed and we can talk about preterm delivery.
Second pregnancy
After the first birth, antibodies remain in the blood of the Rh negative mother. This can significantly complicate the course of the following pregnancies. The presence of antibodies increases the likelihood of a Rhesus conflict.
To avoid this, during the day after the first birth, the drug is injected into the mother’s blood. It is called an anti-Rhesus immunoglobulin. The drug prevents the formation of antibodies, reducing the risk of further complications.
So, Rhesus 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 the rhesus 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 a Rhesus conflict.