Pregnancy and Rhesus conflict, possible complications

Causes of Rhesus sensitization during pregnancy – how long does it occur?

The term “Rhesus” is usually called a complex consisting of 50 specific antigens that are located on red blood cells.

Of all the groups of antigens, proteins of group D are of utmost importance, which are taken into account by specialists at the time of determining the rhesus of the future mother.

Most people in the world have a positive Rh factor, confirmed by the content of D-antigen in their blood (approx. – Rh +). The remaining 15% of this antigen is not in the blood, and their blood is Rh negative (approx. – Rh-).

In normal life, Rh-negative blood is not a sentence – and, in general, does not affect life at all.

But during pregnancy or in the case of a blood transfusion, such a negative feature can cause a lot of problems.

Note: When using the terms “positive” or “negative” Rh factor, the presence or absence of D-antigen is implied exclusively (despite the presence of other protein groups).

Rhesus factor in different nations

• According to statistics, 85% of Europeans have Rh-positive blood.
• But among residents of Asia and India, this percentage is much higher – it reaches 99%.
• In Basques, on the other hand, a third of the population will have a negative Rhesus factor.
• And black inhabitants of the earth possess Rh-negative blood only in 7% of cases.

What is rhesus sensitization?

The specialist usually makes this diagnosis after detecting Rh antibodies in maternal blood.

From the name it is clear that Rh antibodies appear as a “protest” on foreign red blood cells. Compounds of the protein structure in Mom’s blood, with its negative Rh factor, are formed when “foreign” Rh-positive RBC positive children enter the body.

That is, the mother’s immune system refuses to accept other people’s red blood cells as her own, resulting in a Rhesus conflict called sensitization.

The development of a Rhesus conflict is impossible if a baby with a negative Rhesus lives in a Rh negative mother. The conflict arises exclusively with an increase in the sensitivity of the mother’s body to a specific agent.

Not dangerous for the mother herself, sensitization can cause a miscarriage or (which often happens) the development of hemolytic disease of the baby.

Important:

1. The rhesus factor of the baby does not matter if the mother’s blood is Rh-positive.
2. Sensitization can not be afraid if the rhesus negative in the mother and baby.

What are the causes of Rhesus conflict?

The key reasons include…

Simply put, any situation in which there is a mixture of blood between the fetus and the mother can cause the formation of a Rhesus conflict.

That is why specialists categorically do not recommend young mothers with Rh-negative blood to interrupt their first pregnancy, which, in most cases, mothers endure without problems (it is the second pregnancy that accounts for a high percentage of Rh conflicts).

But after an abortion in a Rh negative mother, a 2nd pregnancy may simply not happen.

How long can a Rhesus conflict occur?

Usually, this pathology begins to manifest itself already from the 6-8th week of fetal development – with the appearance of a D protein on red blood cells.

That is why the determination of the content of antibodies in maternal blood is carried out regularly (monthly), from the moment of registration.

On a note:

Changing the Rh factor during pregnancy is impossible due to the fact that this protein is genetically inherited and remains unchanged until the end of life.

The mechanism for the development of the Rhesus conflict during pregnancy – a probability table for the Rhesus factors of parents and the child

The Rh factor is transmitted to the fetus along with papal genes. It is the father who is responsible for what the Rh baby will be.

In every man, D-protein is controlled by genes that are located in a pair of chromosomes.

1. With dominant genes (in 45% of cases), a man has Rh-positive blood. In such a man, children will always be Rh-positive.
2. In the case when a dominant gene is present in one chromosome of the papa and another is recessive (in 55% of cases), only in 50% of cases a Rh-positive baby will be born.

Given that it is extremely difficult to determine genes in advance, these studies are carried out only in case of urgent need (for example, with the IVF procedure).

It is impossible to predict the baby’s rhesus. The possibility of the appearance of crumbs with a negative Rhesus varies from 25 to 75 percent in the case of different parent Rhesus.

But it is important to remember that for the 1st pregnancy, the Rh conflict is possible only in 5% of all cases. During this first pregnancy, there is no mixing of the blood of the mother and baby, therefore, the Rh conflict is a rare occurrence.

The risk increases only when a Rh-negative blood of Rh-positive red blood cells of a baby gets into my mother’s…

• With increased permeability of the placental vessels.
• With gestosis, with the threat of miscarriage or with diseases that can disrupt the integrity of the vessels of the placenta.
• In diagnostic procedures that can lead to a mixture of the blood of the mother and fetus.
• In childbirth and cesarean section.
• In the case of manual separation of the placenta or with its early detachment.
• With surgical intervention (approx. – ectopic, miscarriage, abortion).

After the first penetration of foreign proteins into my mother’s blood, antibodies of the IgM class are synthesized. But the molecule is large, and unable to get into the bloodstream of the fetus – as a result, premature birth becomes the most serious complication (in most cases).

What happens during a second pregnancy?

By the second pregnancy, the mother’s Rh-negative organism is already familiar with the positive Rh factor, and repeated contact with it becomes the reason for the rapid production of a serious amount of much smaller IgG antibodies, which already freely pass to the baby through the placental vessels, causing the above consequences.

In fairness (and peace of expectant mothers) it is worth noting that the Rhesus conflict can be avoided – even if the Rhesus of the mother and the crumbs do not match, with competent observation of the future mother by professional specialists.

What is the likelihood of a Rhesus conflict between mother and fetus – table

Symptoms of the Rh conflict during pregnancy – possible complications for the mother and fetus

There are simply no concrete signs by which to identify – or at least suspect – the future mother of the Rhesus conflict. In addition, this phenomenon does not affect her health at all.

In short, identifying a problem is only possible with an examination.

• Blood test for antibodies. If the titer norm is exceeded, doctors talk about the development of a Rhesus conflict.
• Ultrasound This procedure for Rh conflict will show an increase in the internal organs of the fetus in size, as a result of erythrocyte hemolysis. Doctors also look at the presence of edema of the fetus, at his posture, the thickness of the placenta.
• Dopplerography. It will help assess the quality of blood flow to the vessels of the placenta.
• Cardiography. It is carried out for the analysis of heart rate crumbs.

If there are several symptoms at once, a more thorough examination of the fetus is prescribed to exclude or diagnose hemolytic disease in him.

What is the danger of rhesus conflict?

As mentioned above, the main danger in case of incompatibility of the rhesus of the mother and the baby is considered a hemolytic disease, which can threaten both the fetus and the newborn.

When mother’s antibodies attack the fetal erythrocytes, the second ones quickly collapse, as a result of which anemia begins, an increase in organs, a thickening of the placenta, hypoxia, etc.

The severity of the consequences of the Rh conflict for the crumbs will depend on the period of isoimmunization, on the viability of the fetus and on the activity of the production of the necessary anti-Rhesus immunoglobulins in mother’s blood.

Pregnancy. What to do if a woman has a Rhesus factor negative?

This article is in no way a substitute for the relationship between doctor and patient. It is informative in nature, and is not a guide for self-medication and diagnosis.

The website solady.ru reminds that in all doubtful health situations one should never delay or ignore a call to a doctor!