What Could Be Potential Risk Factors for Autism?

Autism diagnoses are on the rise. According to the CDC, 1 in 59 American children has been identified with autism spectrum disorder —and many parents are trying to do whatever it takes to reduce the risk that their child will develop an autism diagnosis. It's not so easy, however, to identify the risks. And some risks are simply unavoidable: The latest research supports autism as a whole-body system disorder that also affects the brain, and in those with an underlying genetic predisposition, it turns out that the disease can be activated by certain environmental triggers.

A pregnant woman at the doctor's office
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Risk Factors for Autism

  1. Being Male: Males are four times more likely to be autistic than females; the reason for this has not been determined.
  2. Coming From a Family With Autistic Members: Autism does seem to run in families, but it is not contagious. Twins are more likely than other relatives to share autism, and identical twins are extremely likely to share autism (though it may present quite differently in different children).
  3. Having Older ParentsAccording to multiple studies, older parents are more likely to have autistic children than younger parents. The reasons for this, however, are not clear. Could the issue be biological? Or could it be that older parents are older because they had a tougher time finding a mate—because they have shadow symptoms of autism?
  4. Being Exposed to Specific Drugs in Utero: Certain drugs, specifically Valproate and thalidomide, when taken by a pregnant mother, seem to raise the likelihood of autism.
  5. Being Born Early and/or at a Low Weight: There are many reasons why a child might be born prematurely; they include maternal issues ranging from malnutrition and injury to gestational diabetes. These issues can cause a wide range of problems, and autism is one of them.
  6. Spontaneous Mutation: Mutation happens. All the time. Researchers are finding that many people with autism do, in fact, have mutations in their DNA, but these are not clearly linked to any particular pattern or cause.
  7. Being a White Person From a Major Metropolitan Area: In November 2015, the CDC released a report which included a wide range of information about the prevalence of autism in various groups. Among other things, the report cited a higher level of autism among white people from major metropolitan areas. Why should this be the case? There is no consensus, but there are plenty of guesses. Findings from the same report suggest that coming from a family with married parents who have health insurance and a good education seems to increase the risk of autism.

Clearly, some of the "risk factors" listed above are simply unavoidable realities of life. Others may be statistical boondoggles. Is it really likely that having health insurance increases your odds of developing autism? It seems unlikely!

There are also many "risk factors" that may appear to cause autism, but in fact are co-morbidities (disorders that often go along with, but don't cause autism). Some of these include food intolerances, digestive issues, seizure disorders, sleep disorders, bipolar disorder, obsessive compulsive disorder, speech apraxia or sensory integration dysfunction.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Ozonoff S, Young GS, Carter A, et al. Recurrence risk for autism spectrum disorders: a Baby Siblings Research Consortium study. Pediatrics. 2011;128(3):e488-95. doi:10.1542/peds.2010-2825

  3. Wu S, Wu F, Ding Y, Hou J, Bi J, Zhang Z. Advanced parental age and autism risk in children: a systematic review and meta-analysis. Acta Psychiatr Scand. 2017;135(1):29-41. doi:10.1111/acps.12666

  4. Dietert RR, Dietert JM, Dewitt JC. Environmental risk factors for autism. Emerg Health Threats J. 2011;4:7111. doi:10.3402/ehtj.v4i0.7111

  5. Agrawal S, Rao SC, Bulsara MK, Patole SK. Prevalence of Autism Spectrum Disorder in Preterm Infants: A Meta-analysis. Pediatrics. 2018;142(3). doi:10.1542/peds.2018-0134

  6. Kinney DK, Barch DH, Chayka B, Napoleon S, Munir KM. Environmental risk factors for autism: do they help cause de novo genetic mutations that contribute to the disorder?. Med Hypotheses. 2010;74(1):102-6. doi:10.1016/j.mehy.2009.07.052

  7. Levy SE, Giarelli E, Lee LC, et al. Autism spectrum disorder and co-occurring developmental, psychiatric, and medical conditions among children in multiple populations of the United States. J Dev Behav Pediatr. 2010;31(4):267-75. doi:10.1097/DBP.0b013e3181d5d03b

By Lisa Jo Rudy
Lisa Jo Rudy, MDiv, is a writer, advocate, author, and consultant specializing in the field of autism.