Exposure during pregnancy to a common type of pesticide was not linked to autism-related traits in children, according to a new study funded by the National Institutes of Health’s (NIH) Environmental influences on Child Health Outcomes (ECHO) Program.
The findings suggest that, at the relatively low levels of exposure observed in the study, these pesticides may not be associated with autism-related traits during childhood.
Organophosphate pesticides are chemicals used to kill insects. People can come into contact with them through food, especially non-organic fruits and vegetables. Earlier studies on whether exposure to these chemicals before birth suggest that they affect children’s brain and behavioral development and are consistently associated with cognitive challenges, and attention-deficit/hyperactivity disorder (ADHD). However, studies investigating their connection to Autism Spectrum Disorder (ASD) and related traits have had mixed results. Many of those studies included fewer families or looked at groups with higher exposure levels. ECHO Cohort researchers wanted to know whether these pesticides were linked to autism-related traits in a large and geographically diverse group of families across the United States.
Led by Haleigh M. Cavalier, MPH, PhD, of Columbia Mailman School of Public Health, the study included 3,339 mother-child pairs from 20 ECHO Cohort Study Sites across the country. Researchers tested urine samples collected during pregnancy for markers of organophosphate pesticide exposure. They then looked for associations between those markers and children’s scores on a standard questionnaire used to measure autism-related social and behavioral traits.
After accounting for other factors that can affect child development, researchers found no link between higher prenatal pesticide exposure and higher autism-related trait scores. The results were similar when researchers looked at girls and boys separately, focused on children with higher scores on questionnaires measuring autism-related traits, and considered available information about mothers’ diets.
"While we know that that organophosphate pesticides can harm the developing brain, they were not a major driver of characteristics seen in autism at the relatively low exposure levels we observed,” said Dr. Cavalier.
“These results should not be interpreted to mean that such pesticides are safe, nor do they rule out autism-related risks at higher exposures or among more vulnerable groups.”
Because diet can affect both pesticide exposure and child development, researchers also looked at whether diet changed the results. Including diet information shifted some estimates, suggesting diet may have influenced some of the patterns seen in the study. However, those shifts did not change the overall conclusion.
The findings do not address all possible health effects of pesticide exposure. Instead, they point to the need for better ways to measure exposure, more attention to highly exposed or potentially vulnerable populations, and continued research on ways to reduce pesticide exposure.
Future studies should continue to consider diet quality and look more closely at exposure during specific pregnancy stages, pesticide and other chemical mixtures, higher-exposure settings, and genetic factors that may make some children more susceptible.
This collaborative research was published in JAMA Pediatrics .
About ECHO
The ECHO Cohort Consortium is a research program supported by the National Institutes of Health (NIH) with the mission to enhance the health of children for generations to come. ECHO Cohort investigators study the effects of a broad range of early environmental influences on child health and development. For more information, visit echochildren.org .
JAMA Pediatrics
10.1001/jamapediatrics.2026.3785
Observational study
People
Prenatal Organophosphate Exposure and Autism-Related Traits in Children
24-Aug-2026