According to a new study, the iron intake of the mother during pregnancy may be linked to the infant’s autism risk.
Researchers have found that mothers who have kids with autism are less likely to have taken sufficient iron supplements during their pregnancy than other mothers. However, this finding is insufficient to prove a link.
Dr Rebecca J. Schmidt, the leader of the study, from the School of Medicine at the University of California, said that although there was a link, it was only an association. She added that if this was found to be consistent, women would have to ensure that they follow specified recommendation for iron intake prior to becoming pregnant, during the pregnancy and whilst breastfeeding.
Vitamin B and folic acid have also been linked to a high autism risk. Both iron and folic acid are required for foetal brain development and normally form part of recommended prenatal vitamins. According to the authors, this is the first time research has been done on iron intake and autism risk.
The researchers interviewed Californian mothers with children between the ages of two and five about the prenatal supplements, vitamins and multivitamins they had taken before, during and after their pregnancies. They were also questioned about their consumption of fortified cereals and other dietary sources of iron.
They undertook a comparison of 520 children who had received a diagnosis of autism spectrum disorder and 346 children who had developed normally.
They found that mothers in the typical development group had taken iron supplements, with higher than average daily amounts. Prenatal vitamins were found to be the largest source of iron for mothers in both groups, reaching around 30 to 32 milligrams. The balance of the iron was drawn from iron supplements, which were used by around 31% of the females with typically developing kids and around 25% of those with kids suffering from autism.
Overall, mothers in the autism group had daily iron intakes of 51mg per day, compared to 57mg of the mothers in the typical development group. The researchers indicated that both groups were getting above the recommended daily amount.
The Institute of Medicine stated that an adult female should get around 18mg of iron daily, during her reproductive years.
Almost 50% of females become iron deficient during pregnancy and the recommendation is for them to boost their intake to 27mg per day, and to get at least 9mg per day whilst breastfeeding.
The researchers have stated that if these study results could be reproduced in other studies, it may imply that the current recommendations for both pregnant and breastfeeding women are too low.
Since this study only did a comparison between two groups and asked them to try and remember what had happened two to five years previously, there could be another explanation. The lower iron levels may not have caused the autism. However, later autism and iron may be related.
This study has added to the growing amount of evidence that non-genetic risk factors may contribute to the risk of autism and a combination of factors, such as metabolic conditions and maternal age, appear to have a huge impact on risk levels.
Image Credit: Raúl Hernández González