erythroblastosis fe·ta·lis 
(fē-tālĭs)
(fē-tālĭs)n.
A severe hemolytic disease of a fetus or newborn infant caused by the production of maternal antibodies against the fetal red blood cells, usually involving Rh incompatibility between the mother and fetus. Also called RH disease.
[New Latin erythroblastōsis fētālis : erythroblastōsis, erythroblastosis + fētālis, fetal.]