Mothers of children with autism are far less likely to have taken iron supplements before and during their pregnancies than mothers of typically developing children, according to researcers..
The research is the first to examine the relationship between maternal iron intake and having a child with autism spectrum disorder, the authors said.
“The association between lower maternal iron intake and increased ASD risk was strongest during breastfeeding, after adjustment for folic acid intake,” said Dr.Rebecca J. Schmidt, assistant professor in the Department of Public Health Sciences and a researcher affiliated with the MIND Institute.
“Further, the risk associated with low maternal iron intake was much greater when the mother was also older and had metabolic conditions during her pregnancy.”
Among the study participants, mothers with low iron intake were five times more likely to have a child with autism if they were 35 or older at the time of the child’s birth or if they suffered from metabolic conditions such as obesity hypertension or diabetes.
The research involved mother-child pairs enrolled in the Northern California-based Childhood Autism Risks from Genetics and the Environment (CHARGE) Study. The participants included mothers of children with autism and 346 mothers of typically developing children.
The researchers examined the mothers’ iron intake, including vitamins, other nutritional supplements, and breakfast cereals during the three months prior to pregnancy through the end of the pregnancy and breastfeeding. In order to study the iron intake through supplementation, the researchers examined the frequency, dosages and the brands of supplements that the women consumed.
“Iron deficiency, and its resultant anemia, is the most common nutrient deficiency, especially during pregnancy, affecting 40 to 50 percent of women and their infants,” Schmidt said.
“Iron is crucial to early brain development, contributing to neurotransmitter production, myelination and immune function. All three of these pathways have been associated with autism.”
“Iron deficiency is pretty common, and even more common among women with metabolic conditions,” Schmidt said. “However we want to be cautious and wait until this study has been replicated.
“In the meantime the takeaway message for women is do what your doctor recommends. Take vitamins throughout pregnancy, and take the recommended daily dosage. If there are side effects, talk to your doctor about how to address them.”
The study is published in the American Journal of Epidemiology.