BACKGROUND Clinical trials of erythropoietin (EPO) administration to preterm infants have not focused on infants weighing 750 gm or less, the population most likely to receive multiple transfusions because of large phlebotomy losses. It is unknown whether preterm infants weighing 750 gm or less will respond to EPO by accelerating erythropoiesis, or whether EPO administered to this population will decrease
blood transfusions. METHODS We randomly assigned 28 extremely low birth weight preterm infants (mean +/- SEM: 24.7 +/- 0.3 weeks' gestation, 662 +/- 14 gm birth weight), in the first 72 hours of life, to receive either EPO (200 U/kg/day) or placebo for 14 days and administered transfusions only according to protocol over a 21-day study period. All infants received 1 mg/kg/day iron dextran in their total parenteral nutrition solution during the 14-day treatment period. RESULTS During the 21-day study period, a lower number and volume of transfusions were received by the EPO recipients (4.7 +/- 0.7 transfusions per patient and 70 +/- 11 ml/kg per patient) than by the placebo recipients (7.5 +/- 1.1 transfusions per patient and 112 +/- 17 ml/kg per patient; p < 0.05, EPO vs placebo), whereas hematocrits remained similar in the two groups. Reticulocyte counts were similar in both groups on day 1 but were greater in the EPO recipients on day 14 (EPO day 1, 351 +/- 53; EPO day 14, 359 +/- 40 x 10(3)/microl; placebo day 1, 334 +/- 64; placebo day 14, 120 +/- 10 x 10(3)/microl; p < 0.01, EPO vs placebo). Serum ferritin concentrations were similar in both groups at the beginning of the study but were greater in the placebo recipients by day 14 (EPO, 262 +/- 44 microg/L; placebo, 593 +/- 92 microg/L; p < 0.01). No adverse effects of EPO or iron were noted. CONCLUSION The combination of EPO and parenteral iron stimulates erythropoiesis in preterm infants weighing 750 gm or less and results in fewer transfusions during their first 3 weeks of life.