P2C339: Conundrum of Defining Iron Deficiency in Neonates at Birth: Is It Time for a Standardized Definition?

Background: Iron deficiency (ID) is common in the neonatal population but exact incidence is unknown. Up to 17% of premature infants are ID at birth. Infants with ID are likely to experience long-term neurocognitive impairment. Research has shown that adverse effects of ID may be reversible if done so in a timely manner. Hence, appropriate guidelines for diagnosis of ID at birth and management are necessary. Serum ferritin and transferrin saturation (TS) are commonly used to diagnose ID. However, ferritin is an acute phase reactant and increases with infection or inflammation and TS has diurnal variation. Currently, there are no standardized guidelines for diagnosing ID in the neonatal population. We aim to demonstrate the need for standardized guidelines to best screen and diagnose ID in neonates.

Methods: In this prospective cohort study, cord blood samples from preterm and term infants were collected after obtaining maternal informed consent. The cord blood samples were analyzed to determine complete blood count (CBC), serum iron, reticulocyte-hemoglobin (Ret-He), ferritin, TS, and total iron binding capacity (TIBC). Incidence of ID was calculated based on different lab parameters to define ID and results were compared.

Results: A total of 183 cord blood samples were collected and analyzed. The incidence of ID was calculated based on different lab parameters. If iron deficiency is defined as ferritin ≤ 50 μg/L, 11 infants (6%) had ID. If TS ≤ 30% was used, the incidence was 7.1% (13 infants). Similarly, if we define ID as either ferritin ≤ 50 μg/L or TS≤ 30% and ferritin ≤ 50 μg/L and TS≤ 30%, the incidence of ID was 10.9% and 2.2% respectively. Ret-He can indicate iron deficiency with a cut-off of ≤27.4 pg in 2.2% infants and a cut off of ≤31 pg can indicate ID in 12% of infants.

Conclusion: The incidence of ID varies from 2.2% to 12% depending on the definition used. Currently there are no standardized guidelines for diagnosing ID amongst neonates. Guidelines for diagnosing ID in neonates should be standardized to ensure prompt diagnosis and treatment. Further studies are needed to develop the most sensitive and specific definition of ID in order to prevent long term neurocognitive impairment.