Top of the page
The Rh test is a blood test. It checks your blood for a marker called Rh. If you have Rh-negative blood and your baby has Rh-positive blood, your immune system may make antibodies that can harm your baby. When a pregnant woman has these antibodies, it is called Rh sensitization.
The Rh test is done in early 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.
You do not need to do anything before you have this test.
A health professional takes a sample of your blood.
Rh sensitization does not cause any warning symptoms. A blood test is the only way to know if you are at risk for it.
Watch closely for changes in your health, and be sure to contact your doctor, midwife, or nurse call line if you have any problems.
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 call line 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.
Go to https://www.healthwise.net/patientEd
Enter P722 in the search box to learn more about "Rh Antibodies Screening: About This Test".
Current as of: May 29, 2019
Author: Healthwise Staff
Medical Review:Adam Husney MD - Family Medicine & Kathleen Romito MD - Family Medicine & Kirtly Jones MD - Obstetrics and Gynecology
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.
©2006-2019 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.