centa and cause hemolysis of fetal RBCs, which in turn can lead to hemolytic disease of the newborn called erythroblastosis fetalis, an illness of low fetal blood counts that ranges from mild to severe. Sometimes this is lethal for the fetus; in these cases it is called hydrops fetalis.[3]රුධිර ගණ[සංස්කරණය]A complete blood type would describe a full set of 30 substances on the surface of RBCs, and an individual's blood type  is one of many possible combinations of blood-group antigens.[2] Across the 30 blood groups, over 600 different blood-group antigens have been found,[4] but many of these are very rare, some being found mainly in certain ethnic groups.Almost always, an individual has the same blood group for life, but very rarely an individual's blood type changes through addition or suppression of an antigen in infection, malignancy, or autoimmune disease.[5][6][7][8] Another more common cause in blood type change is a bone marrow transplant. Bone-marrow transplants are perfo