Diet During Pregnancy and Autism

It’s well known that a mother’s diet can affect the development of her baby in utero, and there is a ton of advice out there on the things to avoid during pregnancy (such as alcohol and certain types of fish, for example), as well as what foods and supplements are beneficial to the developing fetus’s health.

Health studies indicate that diet and nutrition during pregnancy may have some effect on developmental disorders like Autism.

In recent years some studies have focused on whether a pregnant mother’s diet may increase the chance of her child developing autism spectrum disorder (ASD). Researchers have looked at the link between autism and the mother’s intake of folic acid, vitamin D, certain fats, prenatal vitamins, and more. While some studies have yielded conflicting results, it’s worth taking a look at some of the evidence. After all, with so much uncertainty still surrounding the causes of autism, and its growing prevalence in the population, it is only natural that scientists are looking at mom’s diet as a factor.

What is Autism?

According to the Centers for Disease Control (CDC), autism spectrum disorder (ASD) is a developmental disability, and scientists believe there are many causes. It generally appears before the age of three years, and the symptoms and abilities of people with ASD vary widely. While some people with ASD are nonverbal and need continued support throughout their lives, others can live and work quite independently.

Symptoms of Autism Spectrum Disorder (ASD)

Some of the most common symptoms of ASD include an inability to connect with people or make eye contact, problems judging the emotions of others and difficulties socializing, as well as engaging in repetitive behaviors.

Other symptoms of autism can include:

• Delayed language
• Delayed cognitive or learning skills
• No facial expressions by nine months
• Unusual reactions to sounds, tastes, smells, or touching objects
• Obsessions

Mental health clinicians use behavioral and developmental cues to make a diagnosis. There is no cure for ASD. Early diagnosis and treatment are important for addressing the individual’s needs.

How might maternal diet play a part in development of ASD?

Autism spectrum disorder is one of those diagnoses with many uncertainties. Scientists believe that genetic, biological, and environmental factors may all play a role it’s development, which affects each child differently. What they have found is that ASD diagnoses have become more common than ever before over recent decades. Studies have tried to determine why, and some of these have looked at whether a mother’s diet may play a role. Let’s look at some of the studies.

• The Massachusetts General Hospital Center for Women’s Mental Health with Harvard University lists two studies that show a correlation between dietary intake and ASD. Specifically, an American study called CHARGE (Childhood Autism Risks from Genetics and Environment) found that folic acid intake before and in the early stages of pregnancy, as well as iron intake and multivitamin use, was associated with a risk reduction for ASD. A Norwegian study (Norwegian Mother and Child Cohort Study, or MoBa) also found that folic acid reduced the risk for ASD. However, the website states that a study from the Danish National Birth Cohort (DNBC) found no association between folic acid and multivitamin use and ASD. Researchers went on to say that other factors, such as socioeconomic status, certain behaviors (above), and the pregnancy itself may play a role. ¹

• A paper published in 2020 in Autism Research reviewed 36 studies in nine countries that focused on multivitamins, prenatal vitamins, folic acid, vitamin D, polyunsaturated fatty acid (fish supplements), iron, vitamin in B12, magnesium, and overall maternal diet. The researchers found that while results are not uniform, “higher or moderate intake” of prenatal/multivitamins, folic acid, and vitamin D were associated with reduced risk of ASD. For the other mentioned supplements, the evidence was inconclusive or insufficient. Scientists stressed that continuing research is needed. ²
• An article in the American Journal of Epidemiology looked specifically at fat intake during pregnancy and its potential association with ASD. Although the study was small, researchers did find an association between linoleic acid (found in vegetable oils, nuts and seeds) in pregnant mothers’ diets and lower risk of ASD in their children. They urged caution due to the number of women in the study. The benefits of omega 3 fatty acids from fish in pregnant women’s diet have been studied with conflicting results, but researchers say it is worth investigating in relationship to ASD as well. The report further states, “In particular, we hypothesized that high maternal intakes of ω-3 and other polyunsaturated fats might be protective against ASD because of their role in brain development, and conversely, that low intakes would increase risk.” ³

What do doctors recommend about prenatal diet to reduce the risk of Autism?

All pregnant women should pay attention to their diet during pregnancy to ensure the best possible outcomes for their newborn. The American College of Obstetricians and Gynecologists offers some sound advice on what nutrients pregnant women should be getting through their diets and supplements.

Prenatal Nutrition recommended by the American College of Obstetricians and Gynecologists

Specifically, the organization  recommends these key vitamins, minerals, and nutrients: folic acid, iron, calcium, vitamin D, choline, omega-3 fatty acids, B vitamins, and vitamin C. Specific amounts are listed on the website. Maintaining a healthy diet will not only ensure you are doing all you can for a healthy pregnancy, but you are also giving your child the best possible start in life.

Early intervention is the key with developmental disorders like Autism Spectrum Disorder.

If you suspect your child may have ASD, talk to your doctor about your concerns. Please remember that no one is to blame, but early intervention can help immensely. Many specialists work with babies, children, and adults, offering treatments and therapies ranging from developmental to educational, social, and behavioral. There are also numerous resources available including books, support groups, and well-trained and experienced doctors who have been treating patients with ASD for years. You do not have to do this alone.

Note: *Studies have also been done on the possible relationship between maternal diet and attention deficit hyperactivity disorder (ADHD), also a neurodevelopmental disorder, in offspring. See your pediatrician if you believe your child has ADHD. The World Health Organization (WHO) states that neurodevelopmental disorders are an increasing challenge throughout the world.

^{[1] Autism Spectrum Disorders and Maternal Nutrition. MGH Center for Women’s Health website (Nov. 8th, 2017).}

^{[2] “Maternal dietary factors and the risk of autism spectrum disorders: a systematic review of existing evidence.” Zhong, Caichen, et al., Autism Research 13.10 (2020): 1634-1658.}

^{[3] Maternal Dietary Fat Intake in Association With Autism Spectrum Disorders. Kristen Lyall, Kassandra L. Munger, Éilis J. O’Reilly, Susan L. Santangelo, Alberto Ascherio, American Journal of Epidemiology, Volume 178, Issue 2, 15 July 2013, Pages 209–220, https://doi.org/10.1093/aje/kws433}

^{[4] A Systematic Review of the Link Between Autism Spectrum Disorder and Acetaminophen: A Mystery to Resolve, interpreting data from Parker SE, Collett BR, Werler MM: Maternal acetaminophen use during pregnancy and childhood behavioural problems: Discrepancies between mother- and teacher-reported outcomes. Paediatr Perinat Epidemiol. 2020, 34:299-308. 10.1111/ppe.12601).}

^{[5] Paracetamol use during pregnancy—a call for precautionary action, Bauer, A.Z., Swan, S.H., Kriebel, D., Liew, Z., Taylor, H.S., Bornehag, C.G., Andrade, A.M., Olsen, J., Jensen, R.H., Mitchell, R.T. and Skakkebaek, N.E., 2021. Nature Reviews Endocrinology, 17(12), pp.757-766.}

^{[6] A Systematic Review of the Link Between Autism Spectrum Disorder and Acetaminophen: A Mystery to Resolve, interpreting data from Parker SE, Collett BR, Werler MM: Maternal acetaminophen use during pregnancy and childhood behavioural problems: Discrepancies between mother- and teacher-reported outcomes. Paediatr Perinat Epidemiol. 2020, 34:299-308. 10.1111/ppe.12601).}

^{[7] Paracetamol use during pregnancy—a call for precautionary action, Bauer, A.Z., Swan, S.H., Kriebel, D., Liew, Z., Taylor, H.S., Bornehag, C.G., Andrade, A.M., Olsen, J., Jensen, R.H., Mitchell, R.T. and Skakkebaek, N.E., 2021. Nature Reviews Endocrinology, 17(12), pp.757-766.}