Rh Incompatibility
Rh incompatibility is one of the problems that can occur in pregnancy and childbirth. It is an inequality in a blood component between the mother and the fetus, which can carry some risks for the baby. Here we tell you everything you need to know about it.
What is the Rh factor?
Red blood cells are the cells in charge of transporting oxygen in the blood so that it reaches all tissues. These red blood cells have different types of proteins on their surface. One of these types of proteins will determine the blood group, which can be A, B, AB or 0.
There are other types of proteins found on the surface of these cells, and they are the ones that determine the Rh factor. Depending on whether a person’s red blood cells present this antigen or not, each individual can be Rh + (if their blood cells have this type of protein on their surface) or Rh – (if they don’t). Both the Rh factor and the blood group are inherited from parents to children.
What is Rh incompatibility?
Rh incompatibility is the inequality between the Rh factor of mothers and children. Most of the population is Rh positive. However, when a woman who becomes pregnant is Rh negative, and the father of the baby is Rh positive, the developing fetus may be Rh positive through paternal inheritance.
What happens when it is present?
Normally, the first pregnancy does not carry problems. What happens when there is Rh incompatibility between mother and fetus is that if the fetus ‘blood enters the mother’s bloodstream, her cells will recognize the fetus’ Rh positive as a foreign threat, and the mother’s body will generate antibodies. These antibodies would be responsible for destroying the red blood cells of the fetus.
As we have commented, in the first pregnancy nothing usually happens, since the blood of the fetus usually only passes into the maternal blood at the time of delivery, so there is no time to generate antibodies and that they carry out their attack in that baby.
However, problems can come in subsequent pregnancies. If an Rh negative woman and an Rh positive man have several children, it may be that at the time of delivery of the first child, the woman will generate antibodies against that Rh. The immune system has memory, so in the next pregnancy, these antibodies will continue to circulate in the mother’s blood.
During pregnancy, maternal blood passes continuously from the mother to the fetus. If the fetus is Rh positive, the mother’s anti-Rh antibodies will pass into the fetus’s blood and act, destroying the baby’s red blood cells. This baby will have a very low number of red blood cells at birth, which can be a dangerous situation and is known as hemolytic disease of the newborn.
How is Rh incompatibility prevented?
Currently, pregnancies are closely monitored by primary care physicians and specialists. As soon as a woman becomes pregnant, a blood test is performed that informs us about her blood type and Rh.
In the event that the maternal Rh is negative and there is a risk of developing Rh incompatibility, its prevention is activated. This consists of injecting Rh immune globulin into the mother during pregnancy. It is usually carried out in the 28th week of pregnancy and 72 hours after delivery. These immunoglobulins act like a vaccine, preventing the mother from generating anti-Rh antibodies that could harm possible future pregnancies.
The success rate in preventing incompatibility is very high. However, in pregnancies that have not been properly controlled, there are still cases of hemolytic disease. In this case, the baby will have anemia, jaundice, and even brain and heart damage.
Pregnancy control is the key
To this day, in a pregnancy in which the appropriate controls are carried out, we are not facing a problem, since we have very effective prevention. However, it is important that before any sign of pregnancy, prenatal visits are started so that everything is controlled. If this is not the case, Rh incompatibility can have serious consequences for the baby.
