Impact of Fetal-Neonatal Iron Deficiency on Recognition Memory at 2 Months of Age

Abstract

Objective To assess the effects of fetal-neonatal iron deficiency on recognition memory in early infancy. Perinatal iron deficiency delays or disrupts hippocampal development in animal models and thus may impair related neural functions in human infants, such as recognition memory. Study design Event-related potentials were used in an auditory recognition memory task to compare 2-month-old Chinese infants with iron sufficiency or deficiency at birth. Fetal- neonatal iron deficiency was defined two ways: high zinc protoporphyrin/heme ratio (ZPP/H > 118 μmol/mol) or low serum ferritin (< 75 μg/l) in cord blood. Late slow wave (LSW) was used to measure infant recognition of mother’s voice. Results ERP patterns differed significantly for fetal-neonatal iron deficiency as defined by high cord ZPP/H but not low ferritin. Comparing 35 infants with iron deficiency (ZPP/H > 118 μmol/mol) to 92 with lower ZPP/H (iron-sufficient), only infants with iron sufficiency showed larger LSW amplitude for stranger’s voice than mother’s voice in frontal-central and parietal-occipital locations, indicating the recognition of mother’s voice. Conclusions Infants with iron sufficiency showed electrophysiological evidence of recognizing their mother’s voice, whereas infants with fetal-neonatal iron deficiency did not. Their poorer auditory recognition memory at two months of age is consistent with effects of fetal-neonatal iron deficiency on the developing hippocampus.

Iron Nutriture of the Fetus, Neonate, Infant, and Child

“…Infants with ID can have multiple symptoms that are consistent with impaired hippocampal function, reduced myelination, and altered temperament and altered dopamine metabolism. For example, iron-deficient infants can present with decreased attention and memory [16, 17]; deficits in visual and auditory systems [18, 19]; and altered temperament and social and emotional behaviors [20–22]. Taken together, the evidence implies that ID in early life can permanently alter the brain and nervous system and may explain at least in part why little efficacy has been shown on neurodevelopmental outcomes in iron supplementation trials in young children [23–26].…”

“…Hence, current evidence suggests that it is important to provide a source of iron for children during the first 2 years of life [7, 70, 71]. Both the WHO [72] and the American Academy of Pediatrics [73] recommend exclusive breastfeeding for 6 months.…”

“…However, the worldwide burden is much higher with an estimated 43% globally in 2011 and approximately 70% in Central and West Africa [4]. As will be discussed in more detail below, ID during fetal development and the first 2 years of life is associated with poor growth and decreases in cognitive, motor, and social emotional development [5–7]. Both the United States Department of Health and Human Services and the World Health Organization (WHO) have set goals to reduce ID and iron deficiency anemia (IDA).…”

Guidelines for iron deficiency in pregnancy: hope abounds

“…Low maternal iron intake in the first trimester is associated with an increased incidence of autism (Lyall et al , ), in the second trimester with schizophrenia (Insel et al , ) and in the third trimester with abnormal brain structure in the offspring (Monk et al , ). High quality evidence in the neonatology literature indicates that failure to provide adequate iron to the fetus is associated with immediate (Siddappa et al , ; Geng et al , ) and long‐term neurodevelopmental effects and with an increased risk of postnatal iron deficiency (Zhao et al , ; Santos et al , ; Georgieff et al , ).…”

Maternal iron nutriture as a critical modulator of fetal alcohol spectrum disorder risk in alcohol-exposed pregnancies

“…In the infant, low fetal iron status results in poorer reflexes, indicating neurologic abnormality (Armony-Sivan et al 2004). ID infants also have poor auditory recognition memory at 2 months of age (Geng et al 2015). Furthermore, low cord serum ferritin levels are associated with worsened language skills and fine-motor skills at age 5 (Tamura et al 2002).…”