Transcript BLOOD TYPES ABO and Rh groups

BLOOD TYPES
ABO and Rh groups
Blood Type History
 Blood tests required before marriage
(more to do with diseases
than any other reason…)
We share the ABO system with…
apes, gorillas, chimpanzees, and bonobos
Discovery of Blood Types
 ~1900 blood groups were discovered after more
transfusions began to occur
 Some patients died, some did not
Antigens = Sprinkles
 Toxin that induces an immune response within the body,
especially the production of antibodies
Antigens
 Blood Type A = A antigens
 Blood Type B = B antigens
 Blood Type AB = A and B antigens
 Blood Type O = neither A nor B antigens
Another note on Antigens…
 The ones you have on your RBC’s are recognized
by your body as SELF antigens
 If foreign antigens are discovered by your body,
your body will create antibodies and destroy
those cells
Rh Factor
 Protein that can be present on the surface of RBC’s
 A person either has or does not have the Rh proteins on
surface of RBC’s
 Positive Rh
 Most people have this Rh factor
 Negative Rh
 When you do not have an Rh factor, it is negative
How do you get one?
 It is genetic and is passed on from both parents
 Mom = Rh (-)
o Fetus = Rh (-)
Dad = Rh (-)
 Mom = Rh (+)
Dad = Rh (-)
o Fetus = either Rh (+) or (-)
Rh and Pregnancy
 Rh Incompatibility – when you are Rh (-) and fetus is Rh
(+)
 Usually does not occur in first pregnancy, but can occur in later
pregnancy
What happens?
 When an Rh (-) mother’s blood comes into contact with
blood from her Rh (+) fetus, the Rh-negative mother will
make antibodies against the Rh factor.
 These antibodies attack the Rh factor as if it were a harmful
substance.
 A person with Rh-negative blood who makes Rh antibodies is
called "Rh sensitized."
Rh Sensitivity
 Woman and fetus do not share blood systems.,
 a small amount of blood from the fetus can cross
the placenta into the woman’s system.
 can happen during pregnancy, labor, and birth.
 Especially common if:
 Bleeding during pregnancy
 Manual rotation of a baby in a breech presentation before labor
 Blunt trauma to the abdomen during pregnancy
Problems
 Problems usually do not occur in the first pregnancy because
the baby often is born before the woman’s body
develops many antibodies.
 If preventive treatment is not given during the first
pregnancy and the woman later becomes pregnant with an
Rh-positive fetus, the baby is at risk of Rh disease.
Problems for Fetus
 The Rh antibodies destroy some of the fetal red blood cells.
 This causes hemolytic anemia (RBC’s are destroyed faster than
the body can replace them.)
 Red blood cells carry O2 to all parts of the body. Without
enough RBC’s, the fetus will not get enough O2.
 Hemolytic anemia can lead to serious illness, even death to
the fetus
Prevention
 Blood test can be administered to see the antibodies
 Immunization - Rh immunoglobulin (RhIg) made from
donated blood.
 It targets any Rh (+) cells in and prevents the production of
Rh antibodies.
 can prevent fetal hemolytic anemia in a later pregnancy.