Rh System

An antigen that is sometimes present on the surface of red blood cells is the Rh factor, named after the rhesus monkey in which it was first discovered. Eighty-five percent of the United States' population is Rh-positive (Rh+), meaning that Rh antigens are present. People who do not have Rh antigens are called Rh-negative (Rh).

If an Rh~ person receives a transfusion of blood that has Rh+ antigens, antibodies may react with the antigen and agglutination will occur. The most serious problem with Rh incompatibility occurs during pregnancy. If the mother is Rh~ and the father is Rh+, the child may inherit the dominant Rh+ allele from the father. During delivery, a small amount of the fetus's Rh+ blood may reach the mother's bloodstream. If this happens, the mother will develop antibodies to the Rh factor. If a second Rh+ child is conceived later, the mother's antibodies can cross the placenta and attack the blood of the fetus. This condition is called erythroblastosis fetalis. The fetus may die as a result of this condition, or if the child is born alive, he or she may need an immediate transfusion of Rh+ blood.

To prevent this condition, an Rh~ mother of an Rh+ child can be given antibodies to destroy any Rh+ cells that have entered her bloodstream from the fetus. The mother is, in effect, immunized against the Rh antigen before her immune system has a chance to develop its own antibodies. The antibody treatment prevents Rh sensitization in Rh~ women only if their bodies have not already produced Rh antibodies. If an Rh~ mother has not yet been sensitized, she receives the antibody treatment in the 28th week of pregnancy and again immediately after delivery.

Sirens Sleep Solution

Sirens Sleep Solution

Discover How To Sleep In Peace And Harmony In A World Full Of Uncertainty And Dramatically Improve Your Quality Of Life Today! Finally You Can Fully Equip Yourself With These “Must Have” Tools For Achieving Peace And Calmness And Live A Life Of Comfort That You Deserve!

Get My Free Ebook

Post a comment