Exposure to Common Type of Pesticide During Pregnancy Was Not Linked to Autism-Related Traits in Children

Author(s): Haleigh M. Cavalier, et al.

KEY TAKEAWAYS:

Exposure to organophosphates, a common type of pesticide, during pregnancy was not associated with more autism-related traits in children.

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Who sponsored this study?

The Environmental influences on Child Health Outcomes (ECHO) Program, Office of the Director, National Institutes of Health supported this research.

Why was this study needed?

Organophosphate pesticides are a type of chemical used to control insects on crops. People in the United States may be exposed to low levels of these pesticides through food, especially non-organic produce. These chemicals are known to affect the nervous system, and past studies have consistently linked prenatal organophosphate pesticide exposure to neurodevelopmental outcomes such as thinking and learning problems and attention-deficit hyperactivity disorder (ADHD). However, the research on their link to autism spectrum disorder (ASD) or autism-related traits in children have been mixed. Many studies have had smaller sample sizes or focused on populations with higher pesticide exposure. ECHO researchers wanted to know whether lower level organophosphate pesticide exposure during pregnancy was associated with autism-related traits in children in a large, geographically diverse U.S. sample. They also looked at whether associations differed for girls and boys or were influenced by maternal diet.

What were the study results?

Overall, prenatal exposure to certain pesticides was not associated with an increase in autism-related traits in children. Researchers measured exposure by looking at levels of pesticide-related metabolites—substances produced when the body processes or breaks down certain pesticides—in the participant’s urine during pregnancy.

After accounting for several other factors, higher prenatal levels of these pesticide-related metabolites were not linked to higher scores on a questionnaire that measures autism-related social and behavioral traits. Results were similar when researchers looked separately at girls and boys, when they focused on children with higher autism-related trait scores, and when they included available information about maternal diet.

What was the study's impact?

Given evidence of other neurodevelopmental harms, this study should not be interpreted to mean that these chemicals are safe. However, this study adds to evidence that exposure to this type of pesticide at relatively low levels commonly seen in the general U.S. population may not meaningfully contribute to autism-related traits in childhood. Future studies may collect urine samples at multiple points during pregnancy to better understand pesticide exposure over time, assess links with pesticide mixtures, and focus on particularly vulnerable populations, such as those who are highly exposed or have genetic factors that increase susceptibility.

Who was involved?

Researchers used data from 3,339 mother-child pairs from 20 ECHO Cohort Study Sites across the United States. The analysis included participants who were recruited from 1997 – 2019.

What happened during the study?

During pregnancy, mothers provided urine samples that were later tested for pesticide-related metabolites. Caregivers reported children’s autism-related traits using the Social Responsiveness Scale (SRS), a questionnaire that measures social communication and related behaviors often associated with autism. Children were between ages 2 and 19 when autism-related traits were assessed, with an average age of about 6 years. Researchers used statistical models to examine whether higher prenatal levels of these pesticide-related metabolites were linked to higher SRS scores or to scores high enough to suggest at least mild autism-related traits. They also looked at whether results differed by child sex and whether maternal diet affected the findings.

Footnote: Results reported here are for a single study. Other or future studies may provide new information or different results. You should not make changes to your health without first consulting your healthcare professional.

Where can I learn more?

Access the full journal article, titled “Prenatal Organophosphate Exposure and Autism-Related Traits in Children: Results in the ECHO Cohort” in JAMA Pediatrics.

The content is the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Published August 24, 2026

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Prenatal Exposure to Organophosphate Pesticides Not Associated with Autism-Related Traits in Children in Large NIH Study

Posted on August 24, 2026August 24, 2026 by Jodi Snare

Pregnant mom at farmer's market

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.

Media Contacts

For information or to request an interview, contact the ECHO Program Coordinating Center echocc@dm.duke.edu.

If you are not a member of the media, but have a general inquiry, please contact NIHKidsandEnvironment@od.nih.gov.

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Check out the recent issues of our bi-monthly newsletter, the ECHO Connector, for program news and the latest research findings.

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Following U.S. Dietary Guidelines During Pregnancy May Be Linked to Differences in Chemical Exposure

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Following U.S. Dietary Guidelines During Pregnancy May Be Linked to Differences in Chemical Exposure

Authors: Diana C. Pacyga, Jessie Buckley, et al.

Who sponsored this study?

The Environmental influences on Child Health Outcomes (ECHO) Program, Office of the Director, National Institutes of Health supported this research.

Why was this study needed?

Certain chemicals can end up in food during farming, processing, packaging, storage, or cooking. During pregnancy, some of these chemicals can get into the body through food. In a recent study, ECHO researchers detected, on average, 45 of the 113 chemicals studied in urine samples collected from pregnant participants. However, the U.S. Dietary Guidelines for Americans do not take chemical exposures into account. These chemicals may interfere with how the body’s systems work and could pose a risk for mothers and children. ECHO researchers wanted to know whether following these dietary guidelines closely during pregnancy was linked to lower exposure to chemicals. They also wanted to identify which parts of the diet were most closely related to chemical exposures.

What were the study results?

A diet during pregnancy that more closely followed U.S. Dietary Guidelines for Americans—such as eating more fruits, vegetables, whole grains, and lean proteins—was associated with differences in exposure to several types of chemicals when compared to those who didn’t follow the guidelines as closely.

In this study, following the dietary guidelines was generally associated with lower levels of some chemicals commonly found in food packaging, cooking byproducts, and the environment. For example, levels of one chemical (phthalate) that can leach into food from plastic packaging were about 13% lower among participants who closely followed the dietary guidelines. Eating more lean protein was the biggest factor related to lower levels of most chemicals.

However, following the guidelines was not linked to lower exposure to all chemicals. Participants whose diets more closely followed the dietary guidelines also had higher levels of some pesticides, food preservatives, and chemicals used in personal care products. For example, levels of one pesticide were 9% higher among participants who closely followed the guidelines and eating more fruits and vegetables and less added sugar were the main food components contributing to higher levels.

What was this study's impact?

This study suggests that following the U.S. Dietary Guidelines for Americans during pregnancy may help reduce exposure to many chemicals but could increase exposure to others. The results highlight areas where consumers could benefit from additional guidance to help reduce their dietary chemical exposures. For example, while fresh fruits and vegetables are an important part of a balanced diet during pregnancy, they can also be a source of pesticide exposure. The researchers suggested choosing organic when possible and washing or peeling produce to help reduce pesticide exposure to continue eating these healthy foods. These findings could help researchers and health experts think about how future revisions to dietary guidance might support nutrition while also helping to lower chemical exposure during pregnancy.

Who was involved?

The study included 1,492 pregnant participants from six ECHO Cohort Study Sites in California, Illinois, Michigan, Tennessee, and Georgia.

What happened during the study?

Participants completed a food questionnaire or survey about what they ate around the middle of pregnancy. Researchers used this information to calculate how closely each person’s diet matched the U.S. Dietary Guidelines for Americans, which is measured by the Healthy Eating Index. They also measured 113 chemicals in urine samples collected during pregnancy, covering 10 different classes of chemicals. Then they used statistical analyses to examine how diet quality was related to levels of chemicals in the body.

Footnote: Results reported here are for a single study. Other or future studies may provide new information or different results. You should not make changes to your health without first consulting your healthcare professional.

What happens next?

Future research could help identify practical ways to reduce chemical exposures through diet during pregnancy without lowering nutritional quality. The results may also help inform future updates to dietary recommendations and broader efforts to reduce chemicals in the food supply.

Where can I learn more?

Access the full journal article, titled “Dietary guidelines adherence and pregnancy exposure to 10 classes of priority chemicals: An observational study in the ECHO Cohort,” published in the American Journal of Clinical Nutrition.

The content is the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Published July 8, 2026

Read the associated news release.

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Following U.S. Dietary Guidelines During Pregnancy May Be Linked to Differences in Chemical Exposure

A Healthy Diet During Pregnancy Associated with Lower Exposure to Some—But Not All—Chemicals, NIH Study Finds

Posted on July 8, 2026July 8, 2026 by Jodi Snare

Young mother eating and reading book at home

Following dietary guidelines during pregnancy may reduce exposure to many —but not all— environmental chemicals from food and everyday products, according to a new study of nearly 1,500 pregnant participants funded by the Environmental influences on Child Health Outcomes (ECHO) Program at the National Institutes of Health (NIH).

Diet is one way people can be exposed to environmental chemicals. These chemicals can enter foods during farming, processing, packaging, storage, or cooking. Understanding whether following current dietary recommendations that support a healthy pregnancy could also influence chemical exposures was a key question for ECHO researchers Diana Pacyga, PhD, MS and Jessie Buckley, PhD, MPH of the University of North Carolina Gillings School of Global Public Health.

Recent ECHO research found that pregnant participants were exposed to an average of 45 different environmental chemicals, highlighting the importance of understanding whether healthy eating patterns are linked to differences in exposures. “Lowering exposure to chemicals is particularly important during pregnancy, as earlier ECHO studies have also linked certain chemicals to worse health in mothers and their children” said Dr. Buckley.

Researchers examined diet and chemical exposures in nearly 1,500 pregnant participants in the ECHO Cohort, measuring more than 100 chemicals in urine samples and relating them to diet quality based on how closely participants followed the U.S. Dietary Guidelines for Americans.

Pregnant people whose diets more closely followed the guidelines, including eating more lean protein, had lower levels of some commonly encountered chemicals found in food packaging or formed as byproducts during cooking. For example, levels of one phthalate that can leach into food from plastic packaging were about 13% lower among participants with higher quality diets.

“What we discovered is that following the U.S. Dietary Guidelines may have two benefits—helping meet pregnancy nutrient needs and offering a way to reduce exposure to many common industrial chemicals,” said Dr. Pacyga.

However, the same dietary pattern does not lower exposure to all chemicals. Participants following the guidelines also had higher levels of certain chemicals. Notably, eating more fruits and vegetables and less added sugar were linked with higher levels of some pesticides, which can be found on fresh produce.

Overall, a diet higher in fruits, vegetables, whole grains, and lean proteins and lower in added sugar was linked with lower or higher exposure to different environmental chemicals, underscoring the complex relationship between food and chemical exposures. These findings highlight areas where consumers may benefit from additional guidance to help reduce their dietary chemical exposures.

“Fresh fruits and vegetables are important for a healthy pregnancy diet, but they can also be a source of pesticides,” Dr. Pacyga explained. “Buying organic, when possible, and washing or peeling produce may help reduce exposure while still eating these healthy foods.”

The researchers emphasize that following dietary guidelines remains an important part of a healthy pregnancy, but their findings could help inform future discussions about how dietary guidance addresses environmental exposures.

“A modest revision of the dietary guidelines to include advice on reducing chemical exposures could help protect pregnant women’s health without changing the food recommendations we already know support good nutrition,” Dr. Buckley said.

The researchers note that more studies are needed to better understand these relationships and to identify other practical ways to reduce exposure through diet.

The study, titled “Dietary guidelines adherence and pregnancy exposure to 10 classes of priority chemicals: An observational study in the ECHO Cohort,” was published in the American Journal of Clinical Nutrition.

Media Contacts

For information or to request an interview, contact the ECHO Program Coordinating Center echocc@dm.duke.edu.

If you are not a member of the media, but have a general inquiry, please contact NIHKidsandEnvironment@od.nih.gov.

Connect With Us

Check out the recent issues of our bi-monthly newsletter, the ECHO Connector, for program news and the latest research findings.

To receive the ECHO Connector through email, subscribe here.

Follow the ECHO Program on LinkedIn and X for the latest updates.

Study Reveals Rising Levels of Plastics, Pesticides, and Replacement Chemicals in Pregnant Women

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Study Shows Rising Levels of Plastics, Pesticides, and Replacement Chemicals in Pregnant Women

Authors: Jessie P. Buckley, Tracey J. Woodruff, et al.

Who sponsored this study?

This research was supported by the Environmental influences on Child Health Outcomes (ECHO) program, Office of The Director, National Institutes of Health.

What were the study results?

Most of the chemicals were found in at least one of the women in the study and about a third of the chemicals were found in greater than half of the participants. One fifth of the chemicals were detected in over 90% of the pregnant women indicating widespread exposure to the chemicals measured.

The study found some chemicals were detected more often or were present in higher amounts in non-white women, those with lower education, those who were single, and those exposed to tobacco. Hispanic women had higher levels of some chemicals not included in previous biomonitoring studies including parabens (preservatives) as well as phthalates and bisphenols (from plastics).

The study found that levels of some of the chemicals used as replacements for more toxic ones that were banned or phased out, increased over time and were present in higher amounts than have been seen in previous studies. The levels of several phased out chemicals were found to remain stable or decrease over time.

What was the study's impact?

This is the largest study to date to measure exposure to a wide variety of environmental chemicals in a diverse group of pregnant women across the U.S. The results of this study highlight the widespread and unequal exposure of pregnant women to chemicals from air pollution, food, water, plastics, and other industrial and consumer products.

Why was this study needed?

There is little data on exposure of pregnant women to many pesticides and industrial chemicals, even those that could be harmful during pregnancy and throughout childhood development.

Who was involved?

The study included 171 women from five U.S. states and Puerto Rico who were part of an ECHO cohort. Of these women, 60% were Black or Hispanic.

What happened during the study?

Research team members measured 89 biomarkers for more than 100 chemicals in urine samples from pregnant women in nine ECHO cohorts. Most of the chemicals can be found in pesticides, plastics, sunscreens, personal care products, and flame retardants. Many of the chemicals measured are replacement chemicals: chemicals meant to replace other harmful chemicals (e.g., BPA, phthalates). The team used a new method that measured multiple chemicals in a single urine sample to determine if pregnant women were exposed to the chemicals. The researchers then studied how different factors—such as age, race, education level, and the year the sample was collected—related to the levels of chemicals found.

What happens next?

The research team will continue to study exposures in a larger, diverse population of pregnant women (more than 6,500) to see whether these prenatal chemical exposures are linked to negative birth outcomes. This data will be important for understanding the factors that may contribute to additional negative health effects during pregnancy and childhood.

Where can I learn more?

Access the full journal article titled, “Exposure to contemporary and emerging chemicals in commerce among pregnant women in the United States: The Environmental influences on Child Health Outcomes (ECHO) Program” in Environment Science & Technology.

The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Published May 10, 2022

Access the associated article.

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Study Reveals Rising Levels of Plastics, Pesticides, and Replacement Chemicals in Pregnant Women