There are four different blood types (A, B, AB, and O). There is also an antigen called the Rh factor. If you have the Rh factor on your cells, you are Rh positive. If you don’t have the Rh factor on your cells, you are Rh negative.
There is a 15 percent chance that you are Rh negative. Being Rh negative has no effect on general health, but can cause problems during pregnancy.
People who are Rh negative can make antibodies if exposed to Rh positive blood. This can happen during pregnancy or with a blood transfusion.
If a woman is pregnant, some of the baby’s blood can come in contact with the mother (this is normal). If this happens, antibodies can form. Antibodies are proteins the body makes to protect itself when it reacts with something that is foreign.
If a woman is pregnant and Rh negative and her partner is Rh positive, she is at risk for making Rh antibodies.
HDN can be prevented in 99.9 percent of Rh negative women with injections of WinRho®.
WinRho® is given at 28 weeks and when you deliver, if your baby is Rh positive.
WinRho® is recommended with each pregnancy. It will help protect your baby and any future pregnancies.
Once your body makes antibodies, they do not go away. Every time you get pregnant, the risk to your baby is more serious.
WinRho® has been used since 1968 in Canada with very few serious effects reported. If you have questions, talk to your doctor or healthcare provider.
Without WinRho®, there is a 12 percent chance you will form Rh antibodies that can harm your baby. The risk increases with each pregnancy.
WinRho® is the only way to prevent HDN caused by the Rh factor. If you have any questions or concerns, talk to your doctor or healthcare provider.
Current as of: June 15, 2018
Author: Transfusion Medicine Safety Program, Alberta Health Services
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