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.

Download this summary

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.

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

Nutrition Research

ECHO Nutrition Research

Healthy Food

ECHO researchers use data from more than 64,000 children and their families across the U.S. to examine associations between environmental influences—such as a mother’s diet and access to healthy food during pregnancy, as well as a child’s early diet—and children’s development from pregnancy through childhood.

ECHO Discovery
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Incorporating Early Life Micronutrient Status in ECHO studies of Neurodevelopment

Resources

Visit these government sites to learn more about chemical exposure initiatives.

Medline Plus: Child Nutrition

USDA Nutrition.gov

QUESTIONS

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.

Improving nutrition during pregnancy and childhood is a key priority for public health agencies and organizations in the United States. A child's health—from before birth through adulthood—can be influenced by access to and consumption of nutritious food during critical developmental periods. However, dietary data often provide only a snapshot of a person’s nutritional intake, making it difficult to assess how early-life nutrition affects long-term health. The ECHO Cohort Consortium is tackling this challenge by collecting long-term data on diet and dietary habits during pregnancy and childhood from a large group of participants.

What We're Learning

The ECHO Program has published more than 2,200 articles about the results of its research, covering a wide range of topics. Many of these studies have focused on nutrition during pregnancy and early childhood. Here are recent examples of ECHO research:

Here are some research highlights:

Prenatal Vitamin D Levels Associated with Children’s Brain Development, ECHO Study Suggests
August 2025
Children whose mothers had higher vitamin D levels early in pregnancy tended to score better on problem-solving and learning new information at ages 7–12.

High Refined Grain Intake in Pregnancy Associated with Infant Growth Outcomes
June 2025
Diets high in refined grains and low in whole grains were linked to higher blood sugar in pregnant women and increased risk of low birthweight or preterm babies.

Children Living in Low-income Neighborhoods with Low Food Access at Higher Risk of Developing Asthma, ECHO Study Finds
June 2025
Living in a low-income neighborhood with low food access was associated with higher risks of developing asthma in both cumulative early (age 0-5 years) and cumulative middle (age 0-11 years) childhood.

Executive Functioning May Be Connected to Child Health Behaviors, ECHO Cohort Study Suggests
January 2025
Children with stronger executive function—especially working memory, cognitive flexibility, and behavioral inhibition—tended to eat healthier and be more physically active, though no links were found with sleep.

ECHO Study Investigates Nutrition During Pregnancy and Infant Growth Outcomes
November 2024
Expectant mothers with higher scores on a Healthy Eating Index survey were more likely to have babies with a healthy birthweight and fewer growth issues.

NIH Study Finds No Association Between Prenatal Dietary Patterns and Autism Diagnoses, But Potential Links with Broader Traits

Posted on March 17, 2025 by Jodi Snare

Three validated dietary patterns were not associated with diagnosis, but healthy eating during pregnancy showed a modest link with lower scores for traits related to autism

Expectant mothers with higher diet quality—measured by the Healthy Eating Index (HEI) and the Alternative Healthy Eating Index modified for Pregnancy (AHEI-P)—had children with modestly lower scores for traits related to autism spectrum disorder (ASD), according to ECHO Cohort research led by Kristen Lyall, ScD, and Rachel Vecchione, MPH, of Drexel University. However, the study did not find a significant association between these prenatal dietary patterns and a formal ASD diagnosis.

Previous research has suggested potential links between prenatal diet and neurodevelopmental conditions, but most studies focused on individual foods or nutrients rather than overall dietary patterns. In this study, ECHO researchers examined overall dietary patterns to better understand effects of usual dietary intake across foods.

“This study broadly supports the importance of a healthy diet during pregnancy. Autism is a complex condition with many contributing factors. Here, we found some evidence to suggest a healthy diet during pregnancy may be linked with reduced likelihood of broader traits related to autism, but effect sizes were small,” said Dr. Lyall.

The study included up to 6,084 mother-child pairs from 14 ECHO Cohort Study Sites, which included general population sites and sites with a higher chance of ASD occurring in families.

This collaborative research, titled “Maternal Dietary Patterns During Pregnancy and Child Autism-Related Traits in the Environmental influences on Child Health Outcomes Consortium,” is published in Nutrients.

Nutrition That Aligns With Guidelines During Pregnancy May Be Associated With Better Infant Growth Outcomes, NIH Study Finds

Posted on November 22, 2024August 27, 2025 by Jodi Snare

Expectant mothers who maintain a diet that meets USDA dietary guidelines during pregnancy may be more likely to have infants with healthy birthweights, steadier growth patterns, and potentially a reduced risk of obesity later in childhood, according to a new study funded by the Environmental influences on Child Health Outcomes (ECHO) Program at the National Institutes of Health.

The research, involving more than 2,800 mother-child pairs across eight ECHO Cohort Study Sites, suggests that following a healthy prenatal diet in line with the USDA Dietary Guidelines for Americans could have long-term positive effects on infant growth up to 24 months.

“This study found that eating a healthy diet during pregnancy was linked with a lower chance of extremely rapid infant growth,” said Assiamira Ferrara, MD, PhD, of Kaiser Permanente Northern California Division of Research. Dr. Ferrara noted that rapid growth from birth to 24 months is a strong predictor of obesity later in life.

The study used two dietary measures—the Healthy Eating Index (HEI) and the Empirical Dietary Inflammatory Pattern (EDIP)—to look at maternal eating patterns. The HEI measures overall diet quality. The EDIP score measures how likely a diet is to cause inflammation in the body. Diets with high EDIP scores have been linked to increased levels of inflammation.

Key findings from the research showed that:

Higher HEI scores, reflecting healthier diets, were associated with a 12% reduced chance of infants being born large for gestational age (LGA), alongside lower rates of rapid growth up to 6 and 24 months.
Lower EDIP scores, indicating diets with reduced inflammatory potential, were associated with a 24% higher chance of LGA and had mixed effects on growth: slower from birth to 6 months but faster growth between birth and 12 months. This association was less clear and warrants further study.

To assess rapid growth, the study relied on a measurement called the weight-for-length z-score (WLZ) a tool used to track an infant's growth. It compares a baby’s weight to its length and tells you how far a baby's weight is from the average weight of babies of the same length. Rapid growth was defined as a significant increase in WLZ scores from birth to 6, 12, or 24 months. Babies whose WLZ scores jumped more than expected moved to a higher percentile on the growth chart, meaning they weighed more relative to their peers of the same length.

“The findings support a role for a balanced prenatal diet that aligns with the USDA Dietary Guidelines in promoting healthy birthweights and balanced growth through early childhood,” said Monique Hedderson, PhD, of Kaiser Permanente Northern California Division of Research. “This suggests the need for programs to help improve pregnant womens' access to healthy food and interventions to support healthy eating during pregnancy.”

Researchers said that the findings represent an opportunity for an early obesity prevention strategy. More research is needed to learn how low-inflammatory diets during pregnancy might benefit fetal and infant growth.

About the Study

The study analyzed data collected between 2007 and 2021 from the ECHO Program about 2,854 mother-child pairs. Among the children studied, 48.7% were girls. Children came from diverse racial and ethnic backgrounds: 23.3% White, 22.4% Black, 35.8% Hispanic, 7.8% Asian, and 7.8% other racial backgrounds. Researchers collected information on diet, birth size, and infant growth at 6, 12, and 24 months through medical records and other measurement tools.

This collaborative research was published in JAMA Network Open.

Ferrara, A. & Hedderson, M. (2024) Prenatal Diet and Infant Growth from Birth to Age 24 months. JAMA Network Open. DOI:: 10.1001/jamanetworkopen.2024.45771

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About ECHO: Launched in 2016, the Environmental influences on Child Health Outcomes (ECHO) Program is a research program in the Office of the Director at the NIH with the mission to enhance the health of children for generations to come. ECHO investigators study the effects of a broad range of early environmental influences on child health and development. For more information, visit echochildren.org.

About the NIH: NIH, the nation’s medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information, visit www.nih.gov.

Media Contacts

For information or to request an interview, contact Rebekah Yeager, rebekah.yeager@nih.gov.

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 @ECHOChildHealth for the latest ECHO Program updates on X.

ECHO Study Investigates Nutrition During Pregnancy and Infant Growth Outcomes

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ECHO Study Investigates Nutrition During Pregnancy and Infant Growth Outcomes

Authors: Monique Hedderson, Assiamira Ferrara, 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?

Nearly one-third of children in the U.S. have overweight or obesity, putting them at risk of adverse health outcomes later in life. More research is needed to inform prevention strategies during critical periods of growth, including pregnancy. This study aimed to understand the association between diet quality during pregnancy and infant growth. Rapid growth from birth to 24 months has been identified as a strong predictor of obesity later in life. ECHO researchers looked at how a mother’s nutrition during this crucial period of development might influence the baby’s size at birth and their growth over time.

What were the study results?

Researchers used two indexes to measure healthy eating patterns: the Healthy Eating Index (HEI) and the Empirical Dietary Inflammatory Pattern (EDIP). These scales measure how well foods in a person’s diet align with the U.S. Dietary Guidelines and the diet’s inflammatory potential, respectively. Expectant mothers with higher HEI scores were more likely to have babies with a healthy birthweight and fewer growth issues. Specifically, higher HEI scores were associated with a 12% lower chance of having a baby born large for gestational age (LGA) and a lower chance of rapid growth from birth to 6 months and birth to 24 months. By contrast, a lower score on the EDIP, indicating a less inflammatory diet, was associated with a 24% higher chance of LGA and slower growth to 6 months but faster growth from birth to 12 months. This association was less clear and warrants further study.

What was this study's impact?

The study's findings support the idea that a prenatal diet aligning with U.S. Dietary Guidelines, measured by the HEI, may promote healthy birthweight and infant growth through 24 months. The findings suggest that following USDA dietary guidelines during pregnancy may improve long-term infant growth. This highlights the need for programs or interventions to help pregnant individuals adopt healthy diets.

Who was involved?

The study included 2,854 mother-child pairs from eight ECHO Cohort Study Sites. Among the children, 48.7% were girls, 23.3% were White, 22.4% were Black, 35.8% were Hispanic, 7.8% were Asian, and 7.8% came from other racial backgrounds.

What happened during the study?

The study examined data from mothers and their children in eight different groups that were part of the ECHO Program between 2007 and 2021. Researchers used medical records and study weight and height measurements to track the babies' sizes and growth over time. The mothers' diets during pregnancy were evaluated to calculate HEI and EDIP scores. The study then explored how these diet patterns were associated with babies' size at birth and their growth up to 6, 12, and 24 months old.

To assess rapid growth, the study relied on a measurement called the weight-for-length z-score (WLZ) a tool used to track an infant's growth, it compares a baby’s weight to their length, and tells you how far a baby's weight is from the average weight of babies of the same length. Rapid growth was defined as a significant increase in WLZ scores from birth to 6, 12, or 24 months. Babies whose WLZ scores jumped more than expected moved to a higher percentile on the growth chart, meaning they weighed more relative to their peers of the same length.

Note: 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?

More research is needed to understand the potential benefits of low-inflammatory prenatal dietary patterns in fetal and infant growth. Future studies could investigate how an infant's appetite and feeding habits might influence the connection between a mother's diet during pregnancy and the baby's long-term growth.

Where can I learn more?

Access the full journal article, titled “Prenatal Diet and Infant Growth from Birth to Age 24 months,” in JAMA Network Open.

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

Published November 21, 2024

Read the associated press release.

Download this summary

ECHO Study Investigates Nutrition During Pregnancy and Infant Growth Outcomes

ECHO Cohort Study Finds No Significant Associations Between Prenatal Dietary Patterns and ASD Diagnosis

<< Back to Research Summaries

ECHO Cohort Study Finds No Significant Associations Between Prenatal Dietary Patterns and ASD Diagnosis

Authors: Rachel Vecchione, Kristen Lyall, 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?

Diet during pregnancy plays a major role in fetal development. Prior research has shown associations between several dietary factors and certain neurodevelopmental conditions in children, including autism spectrum disorder (ASD). ASD is a neurodevelopmental condition that affects social communication and behaviors, and presents in a wide variety of behaviors, abilities, and challenges.

This study helped to fill gaps in understanding the relationship between maternal dietary patterns during pregnancy and ASD-related outcomes in children. Most previous studies examining links between prenatal diet and ASD and other neurodevelopmental outcomes have focused on individual foods or nutrients, rather than overall dietary patterns. Dietary patterns may be useful to examine because they summarize the usual intake of a wide range of foods and may capture combined effects across many nutrients. Dietary patterns that capture the intake of recommended foods may also help to provide clearer communication than summaries across individual nutrients. This study therefore aimed to provide a comprehensive assessment by examining several established dietary patterns and their associations with ASD-related traits and diagnoses.

What were the study results?

Dietary patterns examined in this study included the Healthy Eating Index (HEI) and the Alternative Healthy Eating Index modified for Pregnancy (AHEI-P), as well as the Empirical Dietary Inflammatory Index (EDIP). Both the HEI and AHEI-P are validated dietary patterns that are measures of overall diet quality. Higher scores on these patterns indicate better adherence to dietary guidelines. In contrast, higher scores on the EDIP indicate a more pro-inflammatory diet.

The study found that higher prenatal scores on the HEI the AHEI-P were associated with modest decreases in ASD-related traits. However, there were no significant associations between prenatal intake of these dietary patterns and ASD diagnosis. The findings suggest that while there may not be strong associations between prenatal dietary patterns and ASD diagnosis itself, there may be subtle associations with broader traits like social communication difficulties that warrant further investigation.

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 was the study's impact?

This study contributes to the understanding of how prenatal diet may relate to ASD-related characteristics in children. It also highlights the need to further study the potential mechanisms linking prenatal diet to ASD-related traits and to consider broader dietary patterns in addition to individual nutrients and foods.

Who was involved?

The study included 6,084 mother-child pairs from 14 ECHO Cohort Study Sites. The participants were socioeconomically and demographically diverse, drawn from a large U.S.-wide sample, including general population sites and sites with a higher chance of ASD occurring in families.

What happened during the study?

Researchers collected data from individual sites that used Food Frequency Questionnaires to assess diet during pregnancy and enable the calculation of dietary patterns. The study examined associations between three dietary patterns and ASD-related outcomes while adjusting for potential confounding factors such as maternal age, pre-pregnancy BMI, sociodemographic factors, and child characteristics.

What happens next?

Future studies could help researchers confirm the results of this study and explore the subtle associations between prenatal diet and ASD-related traits. Further research could also examine multiple ASD-related outcomes, using larger and more diverse samples, and investigate potential mechanisms linking prenatal diet to ASD-related traits.

Where can I learn more?

Access the full journal article, titled “Maternal Dietary Patterns During Pregnancy and Child Autism-Related Traits in the Environmental influences on Child Health Outcomes Consortium,” in Nutrients.

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

Published November 6, 2024

Read the related research alert.

Download this summary

ECHO Cohort Study Finds No Significant Associations Between Prenatal Dietary Patterns and ASD Diagnosis

Fish But Not Supplements Consumed in Pregnancy Associated With Lower Rates of Autism Diagnosis And Related Traits, ECHO Cohort Study Finds

Authors: Emily Oken, Kristen Lyall, 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?

Fish consumption during pregnancy provides an important source of omega-3 fatty acids, an essential nutrient for supporting child health and neurodevelopment. However, in the U.S., people who are pregnant or can become pregnant are not eating enough fish or get enough omega-3 fatty acids through diet or supplements. Few studies have explored prenatal fish consumption and supplement use in association with autism spectrum disorder (ASD) diagnosis or autism-related traits. This study aims to investigate the relationship between fish consumption or omega-3 supplement use and an ASD diagnosis or the presence of autism-related traits.

What were the study results?

Fish consumption during pregnancy was associated with a 20% lower likelihood of ASD diagnosis and fewer autism-related traits in offspring. The associations were somewhat stronger for female offspring. Taking fish oil supplements containing omega-3 fatty acids during pregnancy was not associated with an ASD diagnosis or autism-related traits. However, supplement use was associated with a slight increase in scores on the Social Responsiveness Scale (SRS), a widely used survey completed by parents or caregivers to report on their child’s possible autism-related traits.

What was the study's impact?

These findings are consistent with current dietary guidelines that support fish intake during pregnancy and support continued public health efforts to encourage fish intake.

Who was involved?

The participants were children born between 1999 and 2019 and their parents at three of the Environmental influences on Child Health Outcomes (ECHO) Cohort research sites. The sites selected from samples considered a higher likelihood for autism, either due to family history or preterm birth.

What happened during the study?

The researchers studied the relationship between maternal fish intake and omega-3/fish oil supplement use during pregnancy and the occurrence of clinician-diagnosed autism and parent-reported autism-related traits. These traits were measured using the Social Responsiveness Scale (SRS), a widely used survey completed by parents or caregivers. Fish consumption and supplement use were assessed based on self-reported dietary information from participants.

Note: 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 examine how chemical contaminants found in some fish could potentially influence child health and development. Additional studies could look at the relationship between self-reported data on fish consumption and supplement use during pregnancy, biological markers of fish consumption, and child health outcomes. Combining biological data and self-reported data could provide a more complete picture of the overall benefits of fish consumption during pregnancy.

Where can I learn more?

Access the full journal article titled “Association of Maternal Fish Consumption and Omega-3 Supplement Use During Pregnancy with Child Autism-Related Outcomes: Results from a Cohort Consortium Analysis” 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 September 2024

Read the associated article

Download this summary

Fish But Not Supplements Consumed in Pregnancy Associated With Lower Rates of Autism Diagnosis And Related Traits, ECHO Cohort Study Finds

Eating Fish But Not Omega-3 Supplements During Pregnancy Associated With Lower Likelihood Of Autism Diagnosis, NIH-Funded Study Finds

Posted on September 3, 2024August 27, 2025 by Jodi Snare

FOR IMMEDIATE RELEASE

Eating any amount of fish during pregnancy was associated with about a 20% lower likelihood of autism spectrum disorder (ASD) diagnosis, particularly in females, and a slight reduction in autism-related traits in offspring, according to a new study funded by the Environmental influences on Child Health Outcomes (ECHO) Program at the National Institutes of Health.

However, researchers did not find the same association with supplements containing omega-3 fatty acids.

Fish is an important source of omega-3 fatty acids, an essential nutrient during pregnancy for supporting maternal health and child neurodevelopment. A recent analysis of ECHO Cohort data revealed that about 25% of the pregnant participants reported never eating fish or consuming it less than once a month during their pregnancy. Even fewer participants reported taking omega-3 fish oil supplements.

ECHO Cohort researchers wanted to see whether low fish consumption and omega-3 supplement use during pregnancy might be associated with the occurrence of an autism diagnosis or parent-reported autism-related traits.

“Our study contributes to a growing body of evidence that demonstrates the role that prenatal diet can play in autism-related outcomes in offspring,” said ECHO Cohort researcher Emily Oken, MD, MPH, of Harvard Medical School.

Dr. Oken said the findings underscored the need for better public health messaging about guidelines for fish consumption for pregnant women, considering the low fish intake in the U.S. and the rising diagnoses of autism.

What happened during the study?

Researchers analyzed data from about 4,000 participants, examining the relationships among fish intake, supplement use, and neurodevelopmental outcomes related to autism.

Fish consumption and omega-3 supplement use were measured with dietary information reported by participants. Participants’ fish consumption was categorized as less than once a month, more than once a month but less than weekly, weekly, and two or more servings per week. About 20% of adult participants reported no fish intake, and most reported not using omega-3 or fish oil supplements.

The researchers then looked at the relationship between maternal fish intake and omega-3 fish oil supplement use during pregnancy and the occurrence of clinician-diagnosed autism and parent-reported autism-related traits. These traits were measured using the Social Responsiveness Scale (SRS), a widely used survey completed by parents or caregivers. Higher scores on the SRS indicate the presence of more autism-related behaviors.

Consuming fish during pregnancy was associated with a lower likelihood of offspring being diagnosed with autism and a slight decrease in total SRS scores compared to not eating fish. These results were consistent across all levels of fish consumption, from "any" amount or "less than once per week" to "more than twice per week." No significant associations were found between omega-3 fish oil supplements and autism diagnosis compared to no use.

Experts recommend that people consume additional omega-3 fatty acids during pregnancy. Prenatal fish intake is a key source of omega-3 fatty acids that are critical for fetal brain development. However, fish and omega-3 fatty acid supplementation in the U.S. is low.

“This study provides yet more evidence for the safety and benefit of regular fish consumption during pregnancy,” said Dr. Oken. “Other proven benefits include lower risk for preterm birth and improved cognitive development.”

Dr. Oken led this collaborative research published in the American Journal of Clinical Nutrition.

Oken, E. & Lyall, K. (2024) Association of maternal fish consumption and ω-3 supplement use during pregnancy with child autism-related outcomes: results from a cohort consortium analysis. American Journal of Clinical Nutrition. 10.1016/j.ajcnut.2024.06.013

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About ECHO: Launched in 2016, the Environmental influences on Child Health Outcomes (ECHO) Program is a research program in the Office of the Director at the NIH with the mission to enhance the health of children for generations to come. ECHO investigators study the effects of a broad range of early environmental influences on child health and development. For more information, visit echochildren.org.

About the NIH: NIH, the nation’s medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information, visit www.nih.gov.

Media Contacts

For information or to request an interview, contact Rebekah Yeager, rebekah.yeager@nih.gov.

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 @ECHOChildHealth on X for the latest ECHO Program updates.

ECHO Study Finds Children with Autism at Higher Risk for a Range of Diverse Health Outcomes

Authors: Elizabeth Kaplan-Kahn, Kristen Lyall, Heather Volk, 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?

Approximately 3% of children in the United States have a diagnosis of autism spectrum disorder (or autism). A large proportion of autism research focuses on understanding the factors that influence the development of autistic traits. However, many people on the autism spectrum report that they would rather prioritize research into the factors that influence their overall health and well-being. This study addresses that priority by investigating the physical, emotional, and overall health outcomes of children on the autism spectrum.

What were the study results?

This study showed that autistic children are at higher risk than non-autistic children for poorer health outcomes indicated by lowest scores in Global Health and highest dysregulation scores (e.g. attention problems, aggressive behavior, and anxious-depressive symptoms). However, there is variability in health outcomes within autistic youth as shown by a group of autistic participants who showed high scores on positive health outcomes across domains. Additionally, compared to non-autistic children, more autistic children were born prematurely, had diagnoses of intellectual disability and ADHD, and had a sibling with autism.

What was the study's impact?

The results of this study offer a glimpse into the diversity of emotional, physical, and overall health outcomes for children on the autism spectrum. A deeper understanding of the range of health outcomes children with autism experience, and the factors that can affect these outcomes, may help families and practitioners identify and target areas for support or intervention.

Who was involved?

The study included over 4,500 children and adolescents at 29 ECHO research sites across the United States, including 286 participants with autism. The participants varied in age from 5 to 20 years old.

What happened during the study?

The researchers compared the health outcomes and demographic characteristics of a large sample of children, with 286 participants with autism and 4,225 participants without. They then used a subsample of 1,809 participants, of which 116 were autistic, to group children with similar physical health, emotional health, and overall well-being outcomes into one of three categories, “positive health,” “poorer health,” and “mixed health.” These categories were mostly determined by the results of multiple Patient-Reported Outcomes Measurement Information System (PROMIS) scales and other reports that evaluated participants’ peer relations, life satisfaction, behavior dysregulation, sleep disturbances, physical activity, etc. The three profiles of participants were then further analyzed to study differences in health outcomes between children on the autism spectrum to non-autistic children.

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 work may focus on understanding the factors that influence poor or positive health for children with autism and how those factors change over time. This work might identify opportunities to support these children and promote positive health outcomes.

Where can I learn more?

Access the full journal article, titled “Describing Multidomain Health Outcomes in Autistic Children in the ECHO Program,” in the Journal of the American Academy of Child and Adolescent Psychiatry.

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

Published August 27, 2024

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ECHO Study Finds Children with Autism at Higher Risk for a Range of Diverse Health Outcomes