Rh incompatibility

People without Rh factor on the surface of their blood cells are Rh-negative and have Rh incompatibility with blood that is Rh-positive. This incompatibility means that when exposed to Rh-positive blood more than once, the immune systems of people with Rh-negative blood produce antibodies to destroy the Rh-positive blood cells.

Pregnancy and blood transfusions are the two most common ways that a person with Rh-negative blood can be exposed to Rh-positive blood.

In a woman with Rh-negative blood who has been exposed at least once to Rh factor (usually from a previous pregnancy), this immune system response can cause serious problems during a future pregnancy if the fetus has Rh-positive blood. The mother's immune system produces Rh antibodies that cross the placenta and attack the fetal blood cells. This can be prevented by giving the mother an injection of antibodies, called RhoGAM.

People requiring blood transfusions have Rh testing and are given only compatible blood.

Last Updated: October 22, 2009

Author: Sandy Jocoy, RN

Medical Review: Sarah Marshall, MD - Family Medicine & William Gilbert, MD - Perinatology

related physicians

related services

Bon Secours International| Sisters of Bon Secours USA| Bon Secours Health System

This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Privacy Policy. How this information was developed to help you make better health decisions.

© 1995-2010 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.