Iron supplementation for infants in the NICU: What preparation, how much, and how long is optimal?

Infants born preterm or with other perinatal risk factors are at added risk for both iron deficiency and overload. Insufficient iron supplementation in the perinatal period is associated with long-term neurodevelopmental effects. Based on this, iron supplements must be targeted to infants' individual iron needs to avoid the adverse effects of both iron deficiency and overload. Enteral iron supplements have been the gold standard in iron supplementation of neonates for many years. However, emerging parenteral formulations may provide an alternative for some infants, such as those who are unable to tolerate oral supplements or who are refractory to enteral supplementation. Optimal dosing and timing of supplementation is an area of ongoing research. In this review, we will summarize available enteral and parenteral iron formulations, review iron measurement parameters, and identify outstanding questions and ongoing research.