Women who take prenatal vitamins early or before pregnancy are less likely to have children with autism

A study led by Dr. Rebecca J. Schmidt, assistant professor in the department of Public Health Sciences in the UC Davis School of Medicine has found that women who did not take prenatal vitamins just before and during the first month of pregnancy were almost twice as likely to have a child with an autistic spectrum disorder as those who did take supplements. The risk of autism increased by seven times for women who had high-risk genetic make up.

The authors hypothesise that the folic acid, which provides the mother with folate needed for the foetus’s neural development, is critical and has the potential to prevent up to 70% of neural tube defects, although there are multiple possible factors for autistic spectrum disorders.

The researchers collected data from about 700 families with children aged between 2 and 5 who had autism or typical development, and also participated in the Childhood Autism Risk from Genetics study from 2003-2009. The researchers admit that there are various factors like for instance the time delay meaning that mothers of typical children are less likely to remember accurately their vitamin intake because they have had less reason to reflect on or be concerned about their children’s development – further research will have to be done to rule out this bias.

However after the first month of pregnancy there was no difference between the mothers who did and did not take vitamins, meaning that by the time women realise they are pregnant it is too late for the foetus to benefit from the vitamins, in terms of the risk of autism. Mothers of autistic children were 4.5 times more likely to have the less efficient MTHFR 677 TT genotype and to report not taking vitamins around the period of conception than were mothers of typically developing children.

If these findings are replicated it will provide a simple and inexpensive way for mothers to reduce the risk of autism in their children.

Source: UC Davis MIND Institute

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First Published in May 2011

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