In 1939 Drs. Philip Levine and Rufus E. Stetson published their findings about a 25 year old mother who had a stillborn baby that died of hemolytic disease of the newborn. Both parents were blood group O, so the husband's blood was used to give his wife a blood transfusion due to blood loss during delivery. However, she suffered a severe transfusion reaction. Since both parents were blood group O, which was believed to be compatible for transfusion, they concluded that there must be a previously undiscovered blood group antigen that was present on the husband's red blood cells (RBCs) but not present on his wife's. This suggested for the "first time" that a mother could make blood group antibodies because of immune sensitization to her fetus's RBCs as her only previous exposure would be the earlier pregnancy. They did not name this blood group antigen at the time, which is why the discovery of the rhesus blood type is credited to Drs. Karl Landsteiner and Alexander S. Wiener with their first publication of their tables for blood-typing and cross-matching in 1940, which was the culmination of years of work. However, there were multiple participants in this scientific race and almost simultaneous publications on this topic. Dr. Philip Levine published his theory that the disease known as erythroblastosis fetalis was due to Rh alloimmunization in 1941 while Drs. Karl Landsteiner and Alexander Wiener published their method to type patients for an antibody causing transfusion reactions, known as “Rh".