Indirect Antiglobulin Test
Also known as: IAT; Indirect Coomb's test; Antibody screen; Indirect Anti-human globulin test
Formal name: Indirect Antiglobulin Test
Related tests: Direct antiglobulin test; Blood typing; Antibody Identification; Type and screen; Crossmatch
Common Questions
1. What happened before the RhIg (RhImmune Globulin) injection was developed?
Prior to development of the injection, Rh-negative mothers would often become sensitized from the blood of their first Rh-positive baby and begin developing anti-Rh antibodies. Any subsequent Rh-positive babies would have some degree of Rh disease, due to the mother’s anti-Rh antibodies attacking the baby’s RBCs. Miscarriages and stillborn babies were relatively common, and those babies who were born often needed immediate blood transfusions to survive. The injection has largely prevented these complications, although a small percent of women do still develop Rh antibodies.
2. Why would a blood typing be necessary on an Rh-negative woman’s husband?
If the woman’s husband is Rh-negative, then all of their babies will be Rh-negative and there will not be an Rh incompatibility. However, if the father is positive, then each baby may be Rh-positive and therefore incompatible with an Rh-negative mother.
3. I’m blood type O and I have a chance of having a baby with ABO hemolytic disease of the newborn. Should I have an IAT done while I’m pregnant?
Hemolytic disease of the newborn may occur when there is an ABO incompatibility between mother and baby, especially with mothers who are blood group O. However, the IAT is not useful in this situation because our bodies naturally produce antibodies against the A and B antigens we do not have on our red blood cells. A mother who is blood type A will naturally have antibodies directed against the B surface antigens on red blood cells, and a mother who is type B will have anti-A antibodies, and so on. An IAT is not used to screen in cases of ABO hemolytic disease of the newborn because it is already known that the antibodies are present in the mother’s blood.
4. Can I get antibodies from donating blood?
No, you will not be exposed to anyone elses blood while donating.
5. If I give my own blood prior to surgery (autologous donation) and receive my own blood back, do I need to worry about antibodies?
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No, since you will not be exposed to foreign RBC antigens, your body will not be stimulated to produce RBC antibodies.
6. Do I need to tell a new doctor about a prior, uneventful transfusion?
Yes. It is important for your doctor to have that information because there is a chance that you produced antibodies to one or more antigens due to that transfusion. While this will not negatively affect your health, it will tell your doctor to be especially vigilant with any subsequent transfusions or pregnancies.
