What is the Rh Disease?

The “Blue Baby Syndrome” has puzzled people for ages. Why was it that some infants were stillborn for no apparent reason?
Many women believed something was wrong with them that they were unable to carry a baby full-term successfully and then in 1937 with the discovery of the rh negative blood factor by Karl Landsteiner, a scientific explanation was finally provided.

Hemolytic disease of the newborn, also known as hemolytic disease of the fetus and newborn, HDN, HDFN, or erythroblastosis fetalis, is an alloimmune condition that develops in a fetus, when the IgG molecules (one of the five main types of antibodies) produced by the mother pass through the placenta. Among these antibodies are some which attack the red blood cells in the fetal circulation; the red blood cells are broken down and the fetus can develop reticulocytosis and anemia. This fetal disease ranges from mild to very severe, and fetal death from heart failure (hydrops fetalis) can occur. When the disease is moderate or severe, many erythroblasts are present in the fetal blood and so these forms of the disease can be called erythroblastosis fetalis (or erythroblastosis foetalis).