Gestational Age-Dependent Reference Values for Iron and Selected Proteins of Iron Metabolism in Serum of Premature Human Neonates

Abstract

The diagnosis and treatment of fetal and neonatal diseases requires knowledge of gestational age-dependent reference ranges for most laboratory values. It was the aim of the present study to establish reference values for serum iron, transferrin, ferritin and ceruloplasmin concentrations in premature neonates, thereby paying attention to the possible changes with gestational age. Blood samples were taken from 100 premature neonates within the first hour of life. Total serum iron, transferrin, ferritin and ceruloplasmin concentrations were determined, transferrin saturation was calculated. Newborns who developed a presumed oxygen radical disease of prematurity were excluded from the study (n = 37), because previous investigations could demonstrate significantly lower serum transferrin and ceruloplasmin concentrations in prematures suffering one of these disorders. Related to gestational age, only serum transferrin concentration showed a statistically significant increase and correlation (r = 0.47; p < 0.0001) with rising age. Although statistically not significant, even serum ferritin concentration increased with rising age of the neonates. None of the investigated laboratory values correlated with birth weight. Only ferritin showed a slight, but statistically not significant increase with higher body mass. We conclude that gestational age-dependent changes of serum transferrin levels must be considered in the judgement of fetal and neonatal diseases, whereas total serum iron and ceruloplasmin concentrations remain rather constant at least during the last weeks of gestation.

Blood Transfusion: A Risk Factor in Retinopathy of Prematurity

“…The transfused adult haemoglobin increases oxygen delivery to the retina which may increase the risk of ROP 23 . Lackman 24 in his study has demonstrated that increased amount of free iron may catalyze fenton reactions, which produce free hydroxyl radicals from superoxide and hydrogen peroxide capable of damaging the retina.…”

Iron Sulfate Supplementation Decreases Zinc Protoporphyrin to Heme Ratio in Premature Infants

“…Measures used to evaluate iron status in adults and children are not useful in neonates because of developmental changes that occur over the first 6 months of life. [9][10][11] Specific bone marrow staining is a reliable index of iron status, but it is not practical for serial assessment of iron status in the premature infant.…”

Deficiência de ferro no feto e no recém-nascido

“…Nas células placentárias, ocorre a liberação do ferro e o retorno da apoproteína para a circulação materna. 5,9 A incorporação de ferro pelo feto é proporcional ao seu peso corporal. Como o mais importante aumento de peso fetal ocorre no último trimestre da vida intrauterina, a criança prematura e a que sofreu retardo de crescimento intrauterino, resultando num baixo peso ao nascer, acumularão menos ferro em comparação ao recém-nascido a termo e de peso adequado para a idade gestacional.…”

“…A ferritina se altera frente a processos inflamatórios, dificultando a interpretação real do status do ferro no organismo. Durante o período neonatal, consideramos valores de ferritina abaixo de 100 ng/mL 9,25 indicativos de deficiência de ferro, sendo indicada a utilização de doses terapêu-ticas de reposição de ferro.…”