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Research Summary

Mothers with Chemical Intolerance Associated with having Children with Neurodevelopmental Disorders

Mankerat Singh and Dr. Jonathan Lai | York University
This article summarizes a research study that examined the relationship between maternal chemical intolerance and children having a diagnosis of autism or Attention Deficit Hyperactivity Disorder (ADHD). Professionals suggest avoiding unnecessary chemical exposure if pregnant. Further research in this area is reportedly needed.

What you need to know

Mothers with chemical intolerance are more likely to have children with Autism Spectrum Disorder, Attention Deficit Hyperactivity Disorder, and immune issues such as allergies and infections.


What is the research about

Chemical Intolerance (CI) is a chronic medical condition in which patients report adverse reactions from exposures to a variety of chemical substances at low doses. The condition affects 10-30% of the general population, but is rarely diagnosed and is largely underreported. Specific chemical exposures have been linked to impaired neurodevelopment in the offspring. This study examines the relationship between mother’s CI and children having a diagnosis of Autism Spectrum Disorder (ASD), or Attention Deficit Hyperactivity Disorder (ADHD).

What did the researchers do                                                                                                                                                       

The study recruited 282 mothers of children with ASD, 258 mothers of children with ADHD, and 154 control mothers who had children without either condition. CI in the mothers was diagnosed using the Quick Environmental Exposure and Sensitivity Inventory (QEESI), the most widely used screening instrument to diagnose CI. QEESI is a survey with 5 self-rating scales which determine intolerance to specific chemical exposures, the severity of symptoms and a measure of ongoing exposures.

An online questionnaire was administered which included QEESI screening along with questions related to demographics and the child’s medical history at the time of collection. Mothers reported on the presence or absence of illnesses such as infections, allergies and asthma in their children, along with sensitivity to odors; the trademark symptom of chemical intolerance.


What did the researchers find

The researchers found that the average CI score was higher in mothers of children with ASD (32/100) and in mothers of children with ADHD (31/100), compared to the control group of mothers (24/100). The researchers also saw that:

●     Women with higher CI scores have a greater likelihood of having children with similar intolerances.

●     Women with higher CI scores had a 3 times higher rate of reporting children with ASD and a 2.3 times higher rate of reporting children with ADHD.

●     Hallmark symptoms of CI were reported at a higher rate in children with ADHD and ASD, 2 and 3.5 times higher respectively.

●     Mothers of children with ASD and ADHD were more likely to report illnesses, allergies, and adverse drug reactions in their children compared to mothers with children without ASD or ADHD.


How can you use this research

This preliminary research warrants further studies to establish clear cause and effect relationships, and to determine specific risk factors. Currently, the American College of Obstetricians and Gynecologists recommends avoiding unnecessary chemical exposures given the link to adverse developmental outcomes. Healthcare providers can provide information to women planning on having children which outline exposure risks and substitutes.


About the Authors

Lynne P. Heilbrun (MPH), Raymond F. Palmer (PhD), Carlos R. Jaen (MD), and Claudia S. Miller (MD) are from the Department of Family and Community Medicine, at the University of Texas Health Science Center in San Antonio.

Melissa D. Svoboda (MD) is from the Department of Pediatrics at the Children’s Hospital of San Antonio/Baylor College of Medicine.

Jimmy Perkins (PhD) is a retired professor at the University Of Texas School Of Public Health in San Antonio.



Heilbrun, L., Palmer, R., Jaen, C., Svoboda, M., Perkins, J., & Miller, C. (2015). Maternal Chemical and Drug Intolerances: Potential Risk Factors for Autism and Attention Deficit Hyperactivity Disorder (ADHD). The Journal of the American Board of Family Medicine, 461-470.



This research summary was written by Mankerat Singh and Dr. Jonathan Lai for the Chair in Autism Spectrum Disorders Treatment and Care Research. This research summary, along with other summaries, can be found on our blog and at


Reproduced with the permission of Dr. Jonathan Weiss (York University). This research summary was developed with funding from the Chair in ASD Treatment and Care Research. The Chair was funded by the Canadian Institutes of Health Research in partnership with Autism Speaks Canada, the Canadian Autism Spectrum Disorders Alliance, Health Canada, Kids Brain Health Network (formerly NeuroDevNet) and the Sinneave Family Foundation. This information appeared originally in the Autism Mental Health Blog (

Photo by Daiga Ellaby on Unsplash

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