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• n  a blood disease characterized by the abnormal presence of erythroblasts in the blood

• About one baby in 300 is born with erythroblastosis.
• Those with more serious cases of erythroblastosis fetalis suffer from the presence in the blood of too many erythroblasts, or immature red blood cells.
• From the machine came a startling fact: of 137 infants with erythroblastosis who got the Rh-negative blood of male donors, 27 died; of 42 who got women's blood, not one died.