When you're trying to become a mother, one of the tests you'll have is a prenatal antibody screen. This prenatal test looks for antibodies in your body, a special protein in your blood that's made by your immune system.

Antibodies are part of the immune system. They help your body fight germs, but sometimes they make mistakes and attack your body's healthy cells. In a Coombs test, your blood is drawn, and lab tests are done to look for antibodies that attack red blood cells. You may also hear it called an antiglobulin test or a red blood cell antibody screen.