- Preterm infants are particularly susceptible to iron deficiency anemia
due to the lack of iron stores built up in the 3rd trimester and also
due to the large number of blood draws required during their hospitalizations.
- AAP recommends 2-3 mg/kg/day iron supplementation in preterm infants
by 2 months of age. This study suggests that there may be some
benefit to starting this level of supplementation with the initial feeds.
If birth weight is 1000-1500g, the suggestion has been made that iron
doses of 4mg/kg/day may be required. With the adequate dose of
Vit E in the formula, no real risk is identified to supplementing these
infants with iron.
- Anemia of prematurity is felt to be due to a failure of premature
infants to produce adequate amounts of erythropoietin. This is
attributed to a delay in the switch from liver to kidney as the primary
site for erythropoietin production. The liver cell's oxygen sensors
are fairly insensitive to hypoxia due to the low oxygen tension in utero.
This leads to difficulty in the liver being able to respond to an anemic
and hypoxic stimuli in the extrauterine environment. Contributing
to this is the increased volume of distribution and clearance of erythropoietin
in the preterm infant.
- There is an increasing amount of research surrounding the use of
erythropoietin therapy to treat anemia of prematurity. If used,
increased erythropoiesis may cause decreased iron stores and may require
supplementation doses of up to 6mg/kg/day during therapy.
Hall RT, Wheeler RE, Benson J, Harris G, Rippetoe L. Feeding Iron-Fortified
Premature Formula During Initial Hospitalization to Infants <1800
Grams Birth Weight. Pediatrics 1993:92(3):409-414.
Roth P. Anemia in Preterm Infants. Pediatrics in Review
Attias D. Pathophysiology and Treatment of Anemia of Prematurity.
Journal of Pediatric Hematology/Oncology 1995, 17(1):13-18.
Groh-Wargo SL, Danish EH, Super DM. Iron Therapy in the Premature
Infant. Pediatric Res 1990, 27:284A.