What is Rhesus:
Rhesus, known as RH factor, is an antigen or protein present on the red blood cells of certain people. Individuals who present this protein in their erythrocytes are RH + and those who do not have it are RH-.
The letters "RH" are the initials of the term Rhesus, discovered in 1940 by doctors Alexander Wiener and Karl Landsteiner, who identified this antigen in the blood of monkeys called Rhesus macacus observing that 85% of human blood is behaved in the same way in them and 15% in a different way.
The ABO system is the classification system of 4 blood groups: "A", "B", "AB", "O" and each one has an antigen that differentiates them. Due to the experiment with Rhesus macacus, a group of "D" antigens was discovered called Rhesus Factors or RH Factor, for which the Rhesuman or Rhogam vaccine is created that eliminates anti-RH, which must be applied around 28 weeks of pregnancy and within 72 hours after delivery in order to avoid fetal erythroblastosis disease or the death of the newborn, if it is very serious, blood transfusions can be performed during pregnancy.
For all of the above, it is important to monitor the presence of antibodies during pregnancy through blood tests, during the first trimester, the sixth, eighth and ninth months.
Hemolytic disease of the newborn or perinatal is a blood disorder due to the incompatibility between the RH of the mother and the RH of the fetus, that is, when the mother is RH- and the child is RH +, the red blood cells of the fetus can pass to the mother's bloodstream through the placenta and her immune system treats the fetal RH + cells as a foreign substance and creates antibodies against them, which can pass to the fetus through the placenta and destroy the red blood cells of the same causing symptoms such as: yellow color of the baby's skin, whites of the eyes, low muscle tone, lethargy, among others.
Consequently, the blood group of both parents must be determined in order to apply the indicated treatment and prevent the aforementioned disease, or if it is necessary to perform transfusions or replace the baby's blood, known as exchange transfusion, with globules. red and whose Rh factor is negative, minimizing the damage that can be caused by the circulation of RH antibodies already present in the baby's bloodstream.