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.
During pregnancy, red blood cells from the unborn baby can cross into the mother's blood through the placenta. If the mother is Rh-negative, her immune system treats Rh-positive fetal cells as if they were a foreign substance. The mother's body makes antibodies against the fetal blood cells. These antibodies may cross back through the placenta into the developing baby. They destroy the baby's circulating red blood cells.