Daawo lagu daaweeyo hooyada uurka leh taas oo ayada dhiigeeda iyo cunuga dhiigiisa ay kala duwan yihiin, oo nooca dhiiga cunuga uu yahay (Rh-positive) ayadana (Rh-negative).
Difaac-jirka Ka-hortagga D-Antigenka waa unug difaac (antibody) oo la siiyo haweenka leh dhiigga Rh-negative si looga hortago in jirkoodu soo saaro difaac ka dhan ah dhiigga ilmaha haddii uu Rh-positive yahay. Tani waxay ka hortagtaa cudurka dhiig-baxa ilmaha marka uu dhasho (Hemolytic Disease of the Newborn).