The anemia of prematurity. Factors governing the erythropoietin response

N Engl J Med. 1977 Mar 24;296(12):647-50. doi: 10.1056/NEJM197703242961202.


We performed sequential studies in 45 premature infants (birth weights less than 1500 g) from 7 to 120 days of age to determine factors governing the erythropoietin response to a declining hemoglobin concentration. The hemoglobin level and the plasma erythropoietin showed a significant inverse correlation (r = 0.50, P less than 0.001), as did, even more strikingly, the plasma erythropoietin response and the infants' oxygen-unloading capacity (r = 0.55, P less than 0.001). In infants with "right-shifted" oxygen-hemoglobin dissociation curves (hemoglobin F less than 30 per cent) hemoglobin levels fell 2 to 3 g per deciliter lower than those in infants with "left-shifted" curves (hemoglobin F greater than 60 per cent) before comparable erythropoietin responses occurred. It appears that premature infants respond appropriately to alterations in oxygen unloading capacity and that the position of the oxygen-hemoglobin dissociation curve and not the hemoglobin concentration alone has a major role in modulated erythropoiesis.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Birth Weight
  • Erythropoietin / blood*
  • Female
  • Fetal Hemoglobin / analysis*
  • Follow-Up Studies
  • Humans
  • Infant, Newborn
  • Infant, Premature*
  • Male
  • Oxygen / blood*
  • Oxygen Consumption
  • Partial Pressure
  • Radioimmunoassay


  • Erythropoietin
  • Fetal Hemoglobin
  • Oxygen