Hello, Antibody tests are done to find certain antibodies that attack red blood cells. Antibodies are proteins made by the immune system. Conditions where antibodies to be made are: Transfusion reactions, Rh sensitization and autoimmune hemolytic anemia. In indirect Coombs test, certain antibodies are in the liquid part of your blood (serum). These antibodies can attack red blood cells but are not attached to your red blood cells. This test is commonly done to find antibodies in a recipient s or donor s blood before transfusion. It is a test to determine whether a woman has Rh positive or negative blood, if negative steps are taken to protect the baby. Normally, a negative test result means that your blood is compactible with the blood you are to receive by transfusion. A negative indirect Coomb s test for Rh factor (Rh antibody titer) in a pregnant woman means that she has not developed antibodies against the Rh-positive blood of her baby. This means the Rh sensitization has not occurred.

Abnormally, a positive indirect Coomb s test result means that your blood is in compactible with the donor s blood and you can't receive blood from that person. Certain conditions affect the test result such as having a blood transfusion in the past, being pregnant within the past three months, taking some medicines like Cephalosporin's, Sulfa medicines, TB, insulin and tetracycline. I would suggest you to consult your physician for further assessment. Thank you.