Definition and causes
Rhesusreaktion from an embryo is a serious condition where the fetus immune system attacks its own blood cells. On the surface of red blood cells which carry oxygen around in the blood, are some proteins called antigens. Some of these form the basis of blood type system AB0 and rhesussystemet, which is vital for the type of blood to be provided by a blood transfusion (the two blood systems are explained in this article).
Where blood with antigens on the surface of blood cells in patients whose immune systems have formed antibodies against these proteins could have fatal consequences.
85% of the population in Denmark has rhesusantigenet in their blood. They called rhesus-positive. The remaining 15% who do not have the antigen in the blood, known as rhesus negative.
Body's immune system can respond to these antigens to develop antibodies, which are proteins that can bind to antigens, and then activate the immune defense cells. Thus, the immune system perceive antigens (and the blood cells they sit on) as something alien, and therefore attacking them. The first time an immune presented to rhesusantigen, it will not attack, but acknowledge that it is something alien. Thus begins the formation of antibodies that will ci
If a rhesus-negative woman becomes pregnant and the father is rhesus-positive, there is a risk that the child is rhesus-positive. The woman is a carrier of a child who in his blood have rhesus antigens on the surface of blood cells. It is worth remembering that mother and child do not share blood, but food and waste is eliminated more than a thin membrane in the placenta.
If there is a transfer of the child's blood to the mother, she will develop antibodies to rhesusantigenet. This can happen if there is an abortion, whether it is spontaneous or provoked, or it may be associated with birth.
Since the mother is immunized, ie. she has antibodies against rhesusantigenet, they will cross the placenta next time she becomes pregnant. If the child is rhesus-positive, the antibodies would attack its red blood cells, which can result in rhesus disease.
Symptoms of rhesusreaktion in the fetus
In light case is only symptomatic jaundice, but more difficult cases may cause anemia in the form of hemolytic anemia, and in worst cases result in death of the fetus.
Treatment of rhesusreaktion in the fetus
The only treatment is when the woman has antibodies, is to provide fetal blood transfusions while still in the womb. Alternatively, you can redeemer child if it is discovered after the 34th week. When the baby is born, it may be more blood transfusions.
Preventing rhesusreaktion of fetus
To reduce the risk of rhesusreaktioner, routinely takes blood samples of all pregnant women. Since 85% is rhesus-positive, they will not have any problems, because they will never develop antibodies.
The remaining 15% treated with rhesusantistoffer if they carry a rhesus-positive child, if they have not previously been immunized (ie, they have not produced antibodies against the background of a previous pregnancy with rhesus-positive fetus). These antibodies would bind to the antigens that may be transferred from the fetus, and thus neutralize them, so the woman's immune system reacts to them and even form antibodies against them.