Features of anemia of prematurity:
(1) premature infant
(2) presence of anemia with hypoxemia
(3) low serum erythropoietin levels
(4) reticulocytosis following administration of erythropoietin and iron
where:
• Iron needs to be administered with the erythropoietin for an optimum response.
Factors contributing to the anemia:
(1) In premature infants oxygen sensing is done in hepatocytes, which are relatively insensitive to hypoxia. In full-term infants oxygen sensing is done in the kidney. There is less secretion of erythropoietin for a degree of anemia.
(2) rapid rate of growth
(3) phlebotomy for laboratory testing
(4) lower hemoglobin in fetus (normal range in cord blood of full-term infant is 13.5 to 20.5).
Although administration of erythropoietin and iron will increase reticulocytosis, it may not reduce the need for blood transfusion or impact clinical outcome.