Health Information and Tools > Health A-Z >  When You Need Rh Immune Globulin

Main Content

Alberta Blood Transfusion Information

When You Need Rh Immune Globulin

​​​​​​What is Rh immune globulin?

Rh immune globulin (WinRho®) is a blood product recommended whenever there is a chance of an Rh negative woman forming antibodies. This could happen with:
  • pregnancy
  • a miscarriage
  • an abortion
  • an amniocentesis or chorionic villous sampling (CVS)
  • trauma (e.g., a car accident) during pregnancy
  • a blood transfusion
  • any other type of risk

What does it mean to be Rh negative?

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.

How does being Rh negative affect 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.

What can happen to my baby if I have Rh antibodies?

If you are pregnant and Rh negative and your baby is Rh positive, antibodies can form. Antibodies can cross the placenta and cause a very bad problem for your baby, which is called hemolytic disease of the newborn (HDN). HDN can cause:
  • low hemoglobin (anemia)
  • toxins in the blood (jaundice)
  • brain damage
  • death

What can I do to lower the risk of HDN?

HDN can be prevented in 99.9 percent of Rh negative women with injections of WinRho®.

When is WinRho® given?

WinRho® is given at 28 weeks and when you deliver, if your baby is Rh positive.

Do I need WinRho® every time I get pregnant?

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.

What are the risks of WinRho®?

WinRho® is a blood product. These steps are taken to make it safe:
  • all donors are tested for viruses (e.g., HIV, Hepatitis B, Hepatitis C)
  • the product is filtered and treated to kill viruses

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.

What if I choose not to get WinRho®?

Without WinRho®, there is a 12 percent chance you will form Rh antibodies that can harm your baby. The risk increases with each pregnancy.

What are the side effects of WinRho®?

Most people who get WinRho® have no side effects. Rarely, WinRho® can cause:
  • pain at the injection site
  • fever (temperature over 38.5 °C or 101.3 °F)
  • feeling weak and unwell (malaise)
  • a headache
  • an allergic reaction (e.g., hives), which is usually not bad and goes away quickly

Is there any other way to prevent HDN?

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