Foetus have severe anaemia and jaundice. A special case of incompatibility has been observed between blood of pregnant mother with blood of foetus. During the delivery of the first child there is a possibility of exposure of the maternal, blood to small amount of blood from foetus. In such cases, the mother starts preparing antibodies against antigen in her blood. In the case of her subsequent pregnancies, the antibody from the mother can leak to blood of foetus and destroy foetal RBCs. This could be fatal to foetus or could cause severe anaemia and jaundice to the foetus. This condition in called erythroblastosis foetalis