Rh incompatibility occurs when a pregnant mother with Rh-negative blood comes into contact with Rh-positive blood from her fetus, resulting in the development of Rh antibodies in the mother's body. This causes the fetus to become anemic, which can lead to hemolytic disease of the newborn. In severe cases, it can lead to death. Therefore, all pregnant women need to be tested for Rh during pregnancy.

Rh incompatibility occurs when a pregnant mother with Rh-negative blood comes into contact with Rh-positive blood from her fetus, leading to the development of Rh antibodies in the mother's body. This causes the fetus to become anemic, which can lead to hemolytic disease of the newborn. In severe cases, it can lead to death. Therefore, all pregnant women need to be tested for Rh during pregnancy.

When a mother and her fetus carry different Rhesus (Rh) protein factors, the condition is called Rh incompatibility or Rh factor incompatibility. This condition occurs when the mother is Rh negative and the fetus is Rh positive.