Insufficient maternal iron intake during pregnancy is linked to less complex gray matter in the newborn’s brain, according to a new study published online in the journal Pediatric Research. The findings indicate the potential significance for the child during even modest changes in the mother’s diet.
Dietary iron is required for normal growth and development and for optimal fetal brain growth. Unfortunately, 35 to 58 percent of healthy women have some degree of iron deficiency, especially in pregnancy.
Worldwide, nearly half of pregnant women are anemic, and this severe maternal iron deficiency can have adverse consequences for the developing fetus.
Past animal studies have found that prenatal brain iron deficiency leads to impaired functioning of the hippocampus, negatively affecting learning and memory, and with delayed maturation of white matter in the brain. Consistent with these findings, it has been shown that newborns with low levels of iron were slower in terms of general motor and neurocognitive development.
For the study, researchers investigated the organization of newborn brain tissue using Diffusion Tensor Imaging (DTI), a magnetic resonance imaging (MRI) technique. The DTI images, taken at an average of 20 days after birth, were used to link the mother’s iron intake during pregnancy to differences in the baby’s cortical gray matter and, to a lesser extent, in major axonal pathways within the underlying white matter of the brain.
The findings showed that the mother’s iron intake during pregnancy correlated inversely with fractional anisotropy (FA) — a useful measurement of tissue organization in the brain — at locations scattered throughout the gray matter of the brain.
This suggests that higher dietary iron intake is linked to greater complexity and therefore greater maturity of cortical gray matter and, conversely, that lower dietary iron is associated with lesser complexity and more immaturity of the developing gray matter shortly after birth.
“These findings are consistent with our expectations,” said principal investigator Bradley S. Peterson, M.D., director of the Institute for the Developing Mind at The Saban Research Institute of Children’s Hospital Los Angeles.
“Neurons become increasingly more complex in their extensions and connections as the brain matures, he said. “And the maturational delays reported previously in animal models and human behavioral studies of iron deficiency would predict that lower iron intake would produce neurons in cortical gray matter that are structurally less complex and more immature. That is what our DTI findings suggest is the case.'”
These correlations were detected in the newborn infants of a sample of 40 healthy adolescent mothers who were adhering to prenatal care and across a range of iron intake. Despite their prenatal care, 14 percent still met clinical criteria for mild anemia, emphasizing the health risks in adolescent mothers and their newborn babies.
“Our imaging findings add brain-based assessments to the growing evidence that common inadequacies in maternal nutrition influence a child’s development, even before birth,” said Peterson, a professor of professor of pediatrics and psychiatry at Keck School of Medicine of the University of Southern California.
Source: Children’s Hospital Los Angeles