Chapter 7 - Risk factors for iron deficiency in neonates

Abstract

Iron, although critically necessary, is both a good and a bad actor because excess unbound iron may be toxic. The physiologic window between the extremes of iron deficiency (ID) and excess is narrow. Official guidelines for identifying managing iron status in ill neonates are based on limited research data and thus are nonspecific and incomplete, especially with parenteral iron administration. Eighty percent of placental-fetal iron transfer occurs during the last trimester. Preterm newborns, without benefit of the third trimester, are at great risk, having accrued limited iron endowment to sustain the greater iron needs for rapid postnatal growth rates and critical neurodevelopment. In addition to prematurity, fetal conditions impacting iron status include multifetal gestation and large or small for gestational age (LGA or SGA). Advances in clinical neonatal intensive care unit (NICU) practice patterns impact iron status in ill newborns. Even at term, maternal ID, alcohol intake, diabetes, obesity, hypertension, and/or placental dysfunction can substantially impair fetal iron endowment. Medically underserved populations are at risk for infantile ID but also at risk for impaired fetal iron endowment. Although not currently a recognized diagnosis, perhaps neonatologists should recognize neonates with low fetal iron endowment (i.e., diagnose congenital ID).