The Assessment of Newborn Iron Stores at Birth: A Review of the Literature and Standards for Ferritin Concentrations

Abstract

Background: Serum ferritin measurements are used in clinical populations to estimate total body iron stores and the risk of subsequent iron deficiency or overload. The lack of normative newborn serum ferritin concentration data between 23 and 41 weeks has led to difficulty in establishing the incidence and degree of abnormal iron status in the neonatal period. Objectives: The primary objective of this review was to summarize the maternal and gestational factors that determine ferritin concentrations in full-term and pre-term newborn infants and to generate comprehensive reference values. The secondary objective was to assess serum ferritin concentrations in newborn infants at risk for abnormal fetal iron metabolism, including maternal diabetes mellitus, intrauterine growth restriction and maternal smoking during pregnancy. Methods: Serum ferritin and gestational age data at birth from 457 low-risk pre-term and term infants of 23–41 weeks gestation obtained from 35 published studies reviewed from a period of 25 years and from recently collected data from our centers were assessed by regression analysis. Slopes and intercepts of the high-risk groups were compared with the standard curve. Results: Umbilical cord serum ferritin concentrations increased with advancing gestational age, from a mean of 63 µg/l at 23 weeks to 171 µg/l at 41 weeks gestation (p < 0.001). The infants of diabetic mothers had a lower intercept than the control infants (p < 0.001). Conclusions: Iron deficiency and overload have been implicated in neurodevelopmental impairments. Normative cord serum ferritin data may permit a more precise assessment of infants who are at risk for abnormal iron status at birth.

Clinical relevance of erythrocyte ferritin in microcytic anemias

“…PF mean concentration in this group (193.04 ± 97.40 ng/ml) was similar Clin Chim Acta Vagace et al to that reported in previous studies in newborns [19,20]. However, we observed in our series a mean EF value of 548.4 ± 32.5 ag/cell, which was almost sixty times higher than that obtained in the control group.…”

Iron supplementation for preterm infants receiving restrictive red blood cell transfusions: reassessment of practice safety

“…No significant differences were found for reticulocyte count and vitamin E levels between both groups. At 8 weeks of age, the cord-blood serum ferritin levels (115 mg l -1 , corresponding to the 50th percentile) of a normative reference group 18 were higher than those of our transfused and non-transfused groups (79 (43 to 107), and 48 (22 to 89) mg l -1 , respectively).…”

“…Yet, adopting the equation of cord-blood levels as a reference value for iron stores no signs of iron excess were, in fact, documented when these serum ferritin levels were compared with those of cord-blood ferritin levels of a gestation-matched normative reference group. 18 Furthermore, although our two study groups vary in terms of acuity of illness and phlebotomy losses leading to RBCTs, resulting most probably from a higher need for disease surveillance in the transfused group, no increased incidence of prematurity associated diseases was found in this group. It is noteworthy that other cordblood iron indicators such as sTfR were not compared because of the different methods used for measurement.…”

“…We aimed to reassess the safety of our iron supplementation practice for VLBW preterm infants receiving restrictive RBCTs. A normative reference value of ferritin, using similar method of analysis, was adopted from previously set standards of cord-blood ferritin concentration 18 to indicate adequate iron status of our preterm infants during initial hospitalization.…”

Neonatal management and outcome in alloimmune hemolytic disease

“…Although iron is essential in early brain development and function, iron overload can have detrimental health effects as well. It causes damage to the liver, heart, and endocrine organs, alters immune response, and increases susceptibility to infection [89]. Iron deficiency in the first 3 months of life is very rare in HDFN and has not been described in neonates that received postnatal top-up transfusions.…”