Exposure to Phthalates During Pregnancy Associated with Autism Traits

March 09, 2020

Folic Acid Can Prevent Harmful Effects

Despite a several decades long rise in prevalence, the cause or causes of autism spectrum disorder (ASD) still remain largely unknown. For years, researchers have primarily pointed a finger towards genetic reasons. However, a dramatic increase in a disorder, like the one exhibited in autism, shows that it becomes less likely that genetics are solely responsible. Researchers have begun to turn to environmental exposures as a likely culprit explaining part of the increase in rates.

A recent study from UMass Amherst’s School of Public Health and Health Sciences looked at a specific toxic compound. The research focused on prenatal exposures of phthalates and the development of autism in young boys.

According to the CDC, phthalates are a group of chemicals used to give plastic more flexibility. Unfortunately, phthalates are ubiquitous in our modern environment. They are used in hundreds of products including vinyl flooring, adhesives, detergents, lubricating oils, automotive plastics, plastic clothes (raincoats), and personal-care products (soaps, shampoos, hair sprays, and nail polishes). Phthalates are also used in the production of polyvinyl chloride plastics, which are used to make products such as plastic packaging film and sheets, garden hoses, inflatable toys, blood-storage containers, medical tubing, and some children’s toys. Unfortunately, this chemical is hard to avoid.

A key finding of the study is that boys exposed in the womb to phthalates were more likely to exhibit autism traits at ages three and four. The study used the term “autistic traits” instead of “autism” due to the young age of the children used in the research. The authors felt there may be a chance some children may exhibit a few symptoms of autism but not be diagnosed with the full disorder later.

A report in Environmental Health News points out that this new study does not prove that phthalates cause autism. However, it does point to a, “…. growing body of evidence that prenatal exposure to certain chemicals may impair social development…”

The UMass Amherst study authors go further on this point and wrote that their research, “provides new insights regarding the potential neurotoxicity of phthalates and … supports earlier research showing increased susceptibility of the developing brain, especially the male fetal brain, to the impact of toxic chemicals.”

How does a mother protect her unborn child from phthalates? This is where the second major finding comes in. The study reported that mothers who had taken recommended doses of folic acid during their first trimester of pregnancy were less likely to have boys who later exhibited autism traits, despite exposure to phthalates. According to lead author Youssef Oulhote, the effect of folic acid during pregnancy was the most important finding of the study.

This is the first study to find that folic acid is neuroprotective in pregnancy from the effects of phthalates on the fetus. Therefore, it is critical for pregnant women to take the recommended daily dose of folic acid. Secondly, pregnant women should try to reduce their exposure to phthalates by avoiding products that are made with the chemical. Unlike many other studies, this research from UMass Amherst finally offers concrete advice for pregnant women to lower the risk of autism in their unborn child.


Youssef Oulhote, Bruce Lanphear, Joseph M. Braun, Glenys M. Webster, Tye E. Arbuckle, Taylor Etzel, Nadine Forget-Dubois, Jean R. Seguin, Maryse F. Bouchard, Amanda MacFarlane, Emmanuel Ouellet, William Fraser, Gina Muckle. Gestational Exposures to Phthalates and Folic Acid, and Autistic Traits in Canadian Children. Environmental Health Perspectives. Publish Date: February 19, 2020. Vol. 128, No. 2.

Centers for Disease Control and Prevention. Phthalates Fact Sheet.

Brian Bienkowski. Autism and phthalates: Exposure in womb linked to autistic traits in boys. Environmental Health News. Publish Date: February 20, 2020

George Citroner. Chemicals Used in Cosmetics May Be Tied to Increased Risk of Autism. Healthline. Publish Date: February 19, 2020.

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