Abstract
It has been well recognized that anemic condition is prevalent in premature infants. It is a purpose of this study to find if the anemia of prematurity is related with the low or lack of erythropoietin production. Serum specimens were harvested from premature infants with gestational age between 30 weeks 5 days and 40 weeks 1 day and birth weight ranging from 1, 600 to 1, 900 g. Specimens were obtained from babies without any clinical abnormality except low birth weight, with age between one to 106 days. Erythropoietin activity was studied utilizing radioimmunoassay method. Erythropoietin was detected since the first day of life and increased after three weeks, when the values reached almost the same level as compared to those of healthy adults. The hemoglobin concentrations in premature infants were decreased rapidly after birth and reached the lowest level approximately eight weeks later. The relatioship between hemoglobin concentration and erythropoietin level showed negative correlation. However, elevated erythropoietin activity still remained within the normal range of those shown in the adults except two cases. Also, negative correlation between hematocrit and erythropoietin activity was observed. All subjects were classified into two groups on the basis of the lowest hemoglobin concentration during the course, i.e. below 10 g/dl as group A and 10 g/dl or above than that as group B concomitantly. The erythropoietin activity in group A showed much higher than that of group B. These findings suggest that the premature infant has the ability to produce erythropoietin. However, producibility of erythropoietin responding to the anemia seems to be lower as compared to other types of anemia.
