Answer (Question 1)

 Outside of the Rh system, which antibody is well documented as a cause of severe hemolytic disease of the newborn?

Other than anti-D, Rh antibodies such as anti-c and anti-E have been reported to cause mild to severe HDN. Antibodies in the Duffy, Kidd, and MNSs systems tend to cause milder forms of the disease.

 

Outside of the Rh system, anti-K is well documented as a cause of severe HDN.