English: Nucleated red cells or normoblast are immature red cells with a retained nucleus. They are usually found only in the circulating blood of the foetus and the newborn infant. Post infancy, their presence in the peripheral blood is indicative of disorder in the blood production. Nucleated red blood cells are immature cells, they do not enter the peripheral blood under normal circumstance. They are often seen in the peripheral blood in leukoerythroblastic anaemia, haemolysis, hypoxia and marrow infiltration.