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Rh Antibodies Screening During Pregnancy: About This Test

What is it?

The Rh antibodies screening test is a blood test. It checks your blood for Rh antibodies. If you have Rh-negative blood and have been exposed to Rh-positive blood, your immune system may make antibodies to attack the Rh-positive blood. When a pregnant woman has these antibodies, it is called Rh sensitization.

Why is this test done?

The Rh antibodies screening test is done during pregnancy to find out if your baby is at risk for Rh disease. This can happen if you have Rh-negative blood and your baby has Rh-positive blood. If your Rh-negative blood mixes with Rh-positive blood, your immune system will make antibodies to attack the Rh-positive blood.

During pregnancy, these antibodies could attach to the baby's red blood cells. This can cause your baby to have serious health problems. The results of this test will help your doctor know how to best care for you and your baby during your pregnancy.

How do you prepare for the test?

In general, there's nothing you have to do before this test, unless your doctor tells you to.

How is the test done?

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

What happens after the test?

  • You will probably be able to go home right away. It depends on the reason for the test.
  • You can go back to your usual activities right away.

Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor or nurse advice line (811 in most provinces and territories) if you are having problems. It's also a good idea to keep a list of the medicines you take. Ask your doctor when you can expect to have your test results.

Where can you learn more?

Go to https://www.healthwise.net/patientEd

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