Coombs Test: About Your Child's Test

What is it?

A Coombs test is a type of antibody test. It checks your child's blood for certain antibodies that attack red blood cells. Antibodies are proteins. They're made by the immune system. Normally, antibodies destroy foreign substances, such as bacteria and viruses.

Why is this test done?

This test is used to check for antibodies:

• In a newborn baby with jaundice.

• In a newborn with Rh-positive blood whose mother has Rh-negative blood.

• In blood before a transfusion.

• Caused by disease or a blood transfusion.

How do you prepare for the test?

In general, you don't need to prepare before your child has this test. The doctor may give you some specific instructions.

How is the test done?

A health professional uses a needle to take a blood sample, usually from the arm.

How long does the test take?

The test will take a few minutes.

Follow-up care is a key part of your child's treatment and safety. Be sure to make and go to all appointments, and call your doctor if your child is having problems. Ask your doctor when you can expect to have your child's test results.

Current as of: May 13, 2023

Content Version: 14.0

Care instructions adapted under license by your healthcare professional. If you have questions about a medical condition or this instruction, always ask your healthcare professional. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.