In each human chromosome is a set of genes. The latter are hereditary characteristics. At the same time, the formation of the genotype directly depends on the adaptive mechanisms. However, children are inherited not only certain features of appearance and survival skills in a particular environment. Offspring can get a predisposition to certain diseases. Blood parameters are also inherited. A few years ago, doctors believed that an Rh-negative child could not be born to Rh-positive parents. However, this claim turned out to be a myth. The chance of having a child with a negative Rh in Rh-positive parents is small, but it exists. In this case, doctors even during pregnancy takeall possible measures to prevent conflict between mother and fetus.
Rh factor: concept
The International Society of Transfusiologists has recognized several blood group systems. Two are the most clinically significant. According to the first, there are only 4 blood groups. At the same time, there are concepts of universal donors and recipients.
According to the second, the entire population of the globe is divided into two groups. Most of them (about 85%) are Rh-positive.
The Rh factor is a protein compound located on the surface of red blood cells. Most people have it, some people don't. In the latter case, it is customary to say that the blood has a negative Rh factor.
This indicator does not affect the state of he alth in any way. It is only relevant during pregnancy, transfusion of liquid connective tissue or its components, as well as during transplantation of a donor organ to a recipient.
This indicator is inherited. But it also happens that a child is born with a negative Rh to positive parents.
Laws of inheritance
From parents to offspring, genes are transmitted that contain information regarding the presence of a protein compound on the surface of erythrocytes. The Rh factor is a dominant trait. In other words, if at least one parent has it, the child will also have it.
But, according to statistics, only 75% of children whose mother and father have a positive Rh factor,protein is found. The rest of the kids don't. In other words, despite the laws of inheritance, an Rh-negative child can be born to Rh-positive parents. In this case, it is customary to talk about the presence of a gene in the mother or father, which is responsible for both the presence and absence of the protein.
Probability of conflict
The table below provides information on what kind of Rh factor a child may have. In addition, the probability of conflict between mother and fetus during pregnancy is indicated.
| Presence/absence of father's protein | Presence/absence of maternal protein | What will be the Rh factor in a child, probability | Conflict, probability |
| Available | Available | 75% "+", 25% "-" | Missing |
| Available | Missing | 50% "+", 50% "-" | Available, 50% |
| Missing | Available | 50% "+", 50% "-" | Missing |
| Missing | Missing | 100% "-" | Missing |
As can be seen from the table, a child with a negative Rh factor can be born to positive parents. However, a few years ago, doctors thought it was impossible.
Parents Rh positive, baby Rh negative - why?
As mentioned above, children receive a certain set of genetic information. In most cases, the presence ofon the surface of erythrocytes of a protein compound. However, in practice there are situations when both parents are Rh-positive, and the child is negative.
This is completely normal. It indicates the presence of a particular gene. In this case, it is enough to find out from relatives (and not necessarily only the closest ones) what their Rh factor is. Surely among family members there is one in whose body there is no protein.
Parents are negative, but baby is positive
In this case, you can begin to rapidly sort things out. The situation when both the father and mother have a positive Rh, and the child has a negative one, is acceptable. But if parents do not have protein on the surface of red blood cells, then it will not appear in children with a 100% guarantee. And in this case, it makes absolutely no sense to look for relatives with a positive Rh.
Danger of conflict between mother and fetus
Immunological incompatibility can occur both during pregnancy and during delivery. According to statistics, Rh conflict is more often diagnosed in women who are carrying a second, third, etc. baby.
During the first pregnancy, it may occur for the following reasons:
- Expectant mother was previously transfused with liquid connective tissue or its components. But during the transfusion, the Rh factor was not taken into account.
- Artificial or natural abortion in the past.
If a positive father and a negative mother had a child with a negativeRh factor, the conflict will come during the next gestation. This is due to the penetration of umbilical cord fluid connective tissue into the maternal circulation during delivery.
The chance of a woman's body becoming sensitized also increases after:
- Caesarean section.
- Bleeding during pregnancy.
- Injury or detachment of the placenta, as well as after its separation by hand.
- Amniocentesis.
- Chorion biopsy.
If during pregnancy it turned out that Rh-positive parents have an Rh-negative child, you should not panic. It is recommended to retake blood for analysis in order to exclude the possibility of an error (in the middle of the 20th century, the blood group and Rh were often incorrectly determined) and, if there is a conflict, to identify it in a timely manner. Ignoring the latter leads to the development of hemolytic disease in the baby. It is accompanied by an increase in size and dysfunction of the following organs:
- Liver.
- Brain.
- Heart muscle.
- Spleen.
- Kidney.
In addition, the fetus may be diagnosed with toxic damage to the central nervous system, better known as bilirubin encephalopathy.
As a rule, the lack of medical intervention leads to miscarriage, stillbirth or fetal death. There is a chance that a child will be born, but in this case, infants are diagnosed with all kinds of hemolyticdisease.
Rhesus conflict is not accompanied by the occurrence of any alarming symptoms in women. Sometimes there are functional disorders characteristic of preeclampsia.
If an Rh-negative baby is born in the event of a conflict, the baby is immediately examined for signs of hemolytic disease.
Symptoms of pathology in infants:
- Anemia.
- Hypoxia.
- Increase in the size of the internal organs, especially the liver and spleen.
- The presence of immature red blood cells in the blood.
Even after the birth of a child, you should not relax. Ignoring the conflict during pregnancy in the future can turn into serious complications for the baby, in particular, and death.
What can be done during gestation
Women at 10, 22 and 32 weeks need to undergo desensitizing therapy. The treatment regimen includes taking vitamins, metabolites, antihistamines, iron and calcium preparations. In addition, ozone therapy is indicated for pregnant women.
If the gestational age exceeds 36 weeks, self-delivery is acceptable. But only under the condition of good he alth of both the mother and the fetus. In severe cases, a caesarean section is performed.
Intrauterine blood transfusion through the umbilical vein may be prescribed to prolong pregnancy.
Doctors' opinions
Currently, experts do not question the fact that a child may haverhesus negative. Why it happened, if the mother and father are positive, parents need to figure it out. If we are not talking about adultery, you need to ask relatives. As a rule, there is a person with a negative Rh in the family.
This situation is fraught with certain risks. In order to prevent the full development of the Rh conflict, a woman should regularly visit her doctor and undergo all the necessary diagnostic procedures. If a danger to the baby is detected, it is necessary to strictly follow the instructions of the specialist.
What research needs to be done:
- A blood test, during which the class and titer of anti-Rhesus antibodies in liquid connective tissue are determined. Donate blood monthly until 32 weeks, then every 14 days.
- Fetal ultrasound.
- Cardiotocography.
- Phono- and electrocardiography.
If necessary, a study of amniotic fluid may be scheduled. However, amniocentesis is a procedure that comes with certain risks. Doctors do not recommend doing it unless absolutely necessary.
In conclusion
The Rh factor is a specific protein compound that is located on the surface of red blood cells - erythrocytes. Most of the world's population (75%) has it. The rest do not have a protein compound in the blood. The Rh factor is a dominant trait. It is included in the human genotype and, accordingly, is inherited. However, in practice there are cases whenRh-negative babies are born to Rh-positive parents. This situation is a variant of the norm, it is detected even during pregnancy. But during the gestation period, it is important to undergo a comprehensive diagnosis in order to timely detect possible pathological conditions.
