Ndị ọkachamara na-ekwu na ọ bụrụ na nwaanyị nwere Rhesus- negative (Rh−) lụọ nwoke nwere 'Rhesus- positive' ( Rh+ ) dị ime mbụ ya ọ bụrụ 'Rhesus- positive' ( Rh+ ), o nwere ike isi n'alọ (placenta) banye n'ọbara nwa ọzọ butere ya ọrịa a kpọrọ "rhesus Disease.
