Women who take folic acid supplements four weeks before becoming pregnant and also during the first weeks of pregnancy have a lower risk of giving birth to children who eventually become diagnosed with an autism spectrum disorder (ASD), Norwegian researchers have reported in JAMA.
Folic acid is the synthetic form of folate, a form of the water-soluble vitamin B9 found in legumes, leafy green vegetables and citrus fruits. Iron is a vital mineral found in spinach, legumes, fortified cereals and animal products. Folate and folic acid play vital roles in the production of new cells, especially during pregnancy and infancy. We need folate or folic acid to produce DNA and RNA, to make healthy red blood cells, and metabolize homocysteine. We need iron to produce a protein in red blood cells that delivers oxygen to tissues and organs – hemoglobin – as well as myoglobin, a protein that supplies the muscles with oxygen.
As background information, the authors wrote, “Supplementation with folic acid around the time of conception reduces the risk of neural tube defects in children. This protective effect has led to mandatory fortification of flour with folic acid in several countries, and it is generally recommended that women planning to become pregnant take a daily supplement of folic acid starting 1 month before conception”
Researchers had not yet determined whether prenatal folic acid – taking folic acid supplements before becoming pregnant – might protect against other neurodevelopmental disorders.
Researchers from UC Davis MIND Institute reported in the American Journal of Clinical Nutrition (June 2012 issue) that taking folic acid during the first month of pregnancy reduces the risk of having a child with autism.
In this latest study, Pal Surén, M.D., M.P.H., of the Norwegian Institute of Public Health, Oslo, Norway, and team set out to investigate whether there might be a link between the intake of maternal folic acid supplements immediately before and during early pregnancy and a subsequent reduction in the risk of autism spectrum disorders in children.
Autism Spectrum Disorders (ASDs) include Asperger’s syndrome, autistic disorder, and pervasive developmental disorder-not otherwise specified (PDD-NOS).
They gathered and examined data from the prospective Norwegian Mother and Child Cohort Study (MoBa), involving 85,176 children. They had all been born in 2002-2008. By the end of the follow-up period (2012), the children ranged in age from 3.3 to 10.2 years, with an average age of 6.4 years.
The researchers were especially interested in folic acid supplementation usage from four weeks before to eight weeks after pregnancy started, “defined as the first day of the last menstrual period before conception”. Timing of folic acid intake is important – folic acid supplementation during late pregnancy has been associated with asthma in young kids. They made adjustments for year of birth, maternal education level, and the number of live-born children delivered (parity).
Below are some highlighted data from the study:
- 0.32% (270) of the children were eventually diagnosed with an ASD
- Of those diagnosed with an ASD, 114 had an autistic disorder, 56 had Asperger’s syndrome, and 100 had PDD-NOS
- An inverse risk was found between folic acid use immediately before and during early pregnancy and subsequently being diagnosed with an ASD
- 0.10% of children whose the mothers took folic acid 4 weeks before and during the first 8 weeks of pregnancy were eventually diagnosed with an ASD
- 0.21% of children whose mothers did not take folic acid during those periods were eventually diagnosed with an ASD
The mothers who took folic acid supplements during the focus-period were more likely to be:
- Of normal body weight – a BMI (body mass index) of less than 25 before pregnancy
- First-time mothers
- Mothers with a planned pregnancy
- College/University graduates
The researchers concluded in an Abstract in the same journal:
“Our main finding was that maternal use of folic acid supplements around the time of conception was associated with a lower risk of autistic disorder. This finding does not establish a causal relation between folic acid use and autistic disorder but provides a rationale for replicating the analyses in other study samples and further investigating genetic factors and other biological mechanisms that may explain the inverse association.”
In an Accompanying Editorial titled “Periconceptional Folic Acid and Risk of Autism Spectrum Disorders”, also in the same issue of JAMA, Robert J. Berry, M.D., M.P.H.T.M., and colleagues at the Centers for Disease Control and Prevention, Atlanta, wrote:
“It is reassuring that the study by Surén et al found no association between folic acid supplementation and an increased risk for autistic disorder or ASDs.
This should ensure that folic acid intake can continue to serve as a tool for the prevention of neural tube birth defects. The potential for a nutritional supplement to reduce the risk of autistic disorder is provocative and should be confirmed in other populations.”
Written by Christian Nordqvist