Rh Grouping

Based on the presence (+) or absence (-) of Rhesus antigen on RBCs; Erythroblastosis foetalis: A condition where an $Rh^-$ mother carries an $Rh^+$ foetus. In a subsequent pregnancy, maternal anti-Rh antibodies can destroy foetal RBCs; Prevented by administering anti-Rh antibodies (Rhogam) to the mother immediately after 1st delivery.