VA Â» Office of Public and Intergovernmental Affairs Â» History of Veterans Day. World War I â known at the time as âThe Great Warâ - officially ended when the Treaty of Versailles was signed on June 28, 1919, in the Palace of Versailles outside the town of Versailles, France.
If your blood mixes with Rh-positive blood, your immune system will react to the Rh factor by making antibodies to destroy it. This immune system response is called Rh sensitization. Rh sensitization can occur during pregnancy if you are Rh-negative and pregnant with a developing baby (fetus) who has Rh-positive blood.
Early in your pregnancy your blood will be tested to determine your blood type and your Rh status â that is, whether you have the Rh (Rhesus) factor, a protein that most people have on the surface of their red blood cells. If you do have the Rh factor, as most people do, your status is Rh-positive. (About 85 percent of Caucasians are Rh-positive, as are 90 to 95 percent of African Americans and 98 to 99 percent of Asian Americans.) If you don't have it, you're Rh-negative, and you'll need to take certain precautions during your pregnancy.