pregnancy

Prenatal Exposure to One Type of PFAS Linked to Small Differences in Children’s Sleep

Posted on by Jodi Snare

Children whose mothers had higher levels of one type of PFAS during pregnancy tended to have slightly more sleep problems between ages 1 and 5, according to a recent ECHO Cohort study led by Sarah D. Geiger, PhD, and Cai Zhang, of the University of Illinois Urbana-Champaign. 

Per- and polyfluoroalkyl substances, or PFAS, are long-lasting chemicals found in many consumer and industrial products. They can remain in the environment and in people’s bodies for a long time. During pregnancy, PFAS can cross the placenta, meaning a developing baby may be exposed before birth. 

Researchers studied 2,836 mother-child pairs from 14 ECHO Cohort study sites across the United States and Puerto Rico. They measured levels of four PFAS chemicals in blood samples collected during pregnancy. Caregivers later answered questions about their children’s sleep, including difficulty falling asleep, waking during the night, nightmares, and resistance at bedtime.  

Higher levels of perfluorooctanoic acid, or PFOA, during pregnancy were linked to slightly more sleep problems in young children. The pattern was similar in boys and girls. The other three PFAS chemicals studied were not clearly linked to children’s sleep problems. 

“Sleep is one of the most common concerns parents raise in early childhood, yet it is rarely studied as an outcome of prenatal chemical exposure,” said Zhang, a doctoral student at the University of Illinois Urbana-Champaign. “The difference for any one child was small, but exposure to these chemicals is widespread, so even small differences are worth continued study.” 

Future studies could examine whether prenatal PFAS exposure continues to relate to sleep as children grow older. Researchers could also study combinations of PFAS, newer replacement chemicals, and sleep measurements collected through wearable devices. 

This collaborative research, titled “Prenatal PFAS exposure and early childhood sleep quality in the ECHO Cohort,” is published in Environmental Research.  

Phthalate Replacement Chemical Associated with Lower Birth Weight

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Phthalate Replacement Chemical Associated with Lower Birth Weight

Author(s): Leonardo Trasande, et al.

KEY TAKEAWAYS:

  • Higher pregnancy levels of some markers for di(isononyl) cyclohexane-1,2-dicarboxylate (DINCH) exposure were linked to slightly smaller babies at birth. DINCH is a chemical used to soften plastics and replace some phthalates.

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Phthalate Replacement Chemical Associated with Lower Birth Weight

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?

Phthalates are widely used chemicals found in many everyday items such as food packaging, flooring, building materials, medicine coatings, medical supplies, cosmetics, and personal care products. These chemicals have been linked to adverse pregnancy and child health outcomes. As manufacturers replace phthalates with alternatives presumed to be safer such as di(isononyl) cyclohexane-1,2-dicarboxylate (DINCH), ECHO researchers want to understand whether these newer chemicals may also affect maternal and child health.

 

What were the study results?

Researchers found that higher levels of chemical markers related to DINCH exposure in urine during pregnancy were associated with lower birth weight and a greater likelihood that infants would be born small for gestational age. Every tenfold increase in exposure to DINCH resulted in a 27-gram reduction in newborn birth weight. These associations differed by infant sex: associations with babies’ physical length were stronger among boys while associations with being small-for-gestational-age were stronger among girls. Exposure during the third trimester appeared more strongly associated with reduced birth weight for gestational age than exposure earlier in pregnancy.

The researchers also found that measurable levels of these DINCH markers were common among pregnant participants, suggesting widespread exposure in this population.

 

What was the study's impact?

These findings suggest that prenatal exposure to this phthalate alternative may be associated with differences in fetal growth. However, the study was observational and cannot determine whether DINCH directly caused these outcomes. Additional research could help researchers understand how DINCH may affect pregnancy and fetal development and evaluate the safety of other phthalate replacements.

 

Who was involved?

Researchers analyzed data from 6,617 pregnancies at 22 ECHO Cohort study sites.

 

What happened during the study?

Researchers measured three DINCH breakdown products in urine from pregnant women. They averaged measurements across pregnancy and within trimesters when available. They compared these levels with the babies weight and length at birth, the duration of pregnancy, and size for gestational age, accounting for maternal age, education, prior births, race and ethnicity, child sex, and study site.

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 exposure to di(isononyl) cyclohexane-1,2-dicarboxylate and adverse birth outcomes in the USA: a prospective analysis of births in a large American birth cohort,” in Environment International.

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

Published November 3, 2026

Read the related news release(opens in new tab).

Read More Research Summaries

Prenatal Exposure to One Type of PFAS Linked to Small Differences in Children’s Sleep

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Prenatal Exposure to One Type of PFAS Linked to Small Differences in Children’s Sleep

Author(s): Cai Zhang, Sarah Geiger, et al.

KEY TAKEAWAYS:

  • Children whose mothers had higher levels of perfluorooctanoic acid (PFOA) during pregnancy tended to have slightly more sleep problems between ages 1 and 5.
  • Other per- and polyfluoroalkyl substances (PFAS) studied were not clearly linked to children’s sleep problems.

Download this summary

Prenatal Exposure to One Type of PFAS Linked to Small Differences in Children’s Sleep

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?

PFAS are long-lasting chemicals found in many consumer and industrial products, including nonstick cookware, food packaging, stain-resistant materials, and firefighting foam. These chemicals can stay in the environment and in people’s bodies for a long time. During pregnancy, PFAS can cross the placenta, meaning a baby may be exposed before birth.

Sleep is important for young children’s growth, learning, behavior, and emotional health. Some earlier studies suggested that PFAS exposure during pregnancy might be linked to children’s sleep, but large studies following children across early childhood have been limited. This study uses data from the nationwide ECHO Cohort to better understand whether prenatal exposure to four PFAS chemicals was associated with sleep problems in children ages 1 to 5.

 

What were the study results?

Higher levels of PFOA during pregnancy were associated with slightly higher sleep problem scores in young children. This means children whose mothers had higher PFOA levels during pregnancy tended to have somewhat poorer sleep quality between ages 1 and 5. This association was seen in both boys and girls.

The other three PFAS chemicals studied were not clearly linked to children’s sleep problems. Children exposed to perfluorooctanesulfonic acid (PFOS) and perfluorononanoic acid (PFNA) tended to have slightly more sleep problems, while those exposed to perfluorohexane sulfonic acid (PFHxS) tended to have slightly fewer. None of the associations were strong enough to confirm a link.

 

What was the study's impact?

The sleep score differences linked with PFOA exposure were small for any one child. However, PFAS exposure is common, so even small changes could matter across a large population. Because sleep problems in early childhood can affect behavior, emotional regulation, learning, and family routines, the study authors suggest that reducing PFAS exposure during pregnancy may support children’s sleep health and overall development.

 

Who was involved?

The study included 2,836 mother–child pairs from 14 ECHO Cohort study sites across the United States and Puerto Rico. The children contributed 4,451 sleep assessments between ages 1 and 5. The study sample included families from a range of racial, ethnic, educational, and income backgrounds.

 

What happened during the study?

Researchers measured levels of four PFAS chemicals in blood samples collected from mothers during pregnancy. The chemicals included PFOA, PFOS, PFNA, and PFHxS. When more than one pregnancy blood sample was available, the researchers averaged the measurements to estimate overall prenatal exposure.

Caregivers later reported on children’s sleep using the Child Behavior Checklist Sleep Problems scale. This questionnaire asks about common sleep-related behaviors, such as trouble falling asleep, waking often during the night, nightmares, and resistance at bedtime. Researchers compared children’s sleep scores with their mothers’ PFAS levels during pregnancy while accounting for other factors that could affect sleep, such as maternal age, education, race and ethnicity, pre-pregnancy body mass index, smoking during pregnancy, study site, birth year, and child age at assessment.

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 PFAS exposure and early childhood sleep quality in the ECHO Cohort,” in Environmental Research.

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

Published October 1, 2026

Read the related news release(opens in new tab).

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Higher prenatal fluoride exposure in public drinking water linked to lower fluid cognition scores in children

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Higher prenatal fluoride exposure in public drinking water linked to lower fluid cognition scores in children

Author(s): Katrina R. Simon, Amy E. Margolis, Anne E. Nigra, et al.

KEY TAKEAWAYS:

  • Children whose mothers were potentially exposed to higher fluoride levels in public drinking water during pregnancy tended to score lower on tests of problem-solving, memory, attention, and adapting to new information.
  • The association was strongest when fluoride levels in neighborhood drinking water were close to or above the current U.S. recommended levels.

Download this summary

Higher prenatal fluoride exposure in public drinking water linked to lower fluid cognition scores in children

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?

Fluoride is found naturally in some water sources and is also added to many public drinking water systems to help prevent cavities. Current United States guidance for fluoridated water is designed to support dental health and reduce the risk of tooth or bone problems, but more evidence is needed to fully understand the possible effects of fluoridated water on children’s brain development. In a recent review, the National Toxicology Program found moderate evidence that children exposed to fluoride levels above 1.5 milligrams in each liter of drinking water may have lower IQ scores. The report also noted that there is limited research on lower fluoride levels, especially in U.S. populations.

ECHO researchers wanted to know whether fluoride levels in public drinking water during pregnancy were related to children’s cognition, or thinking and learning skills, later in childhood.

 

What were the study results?

Children whose mothers were potentially exposed to higher fluoride levels in public drinking water during pregnancy tended to score lower on tests of fluid cognition. Fluid cognition includes skills such as problem-solving, memory, attention, and adapting to new information.

The association was strongest at fluoride levels near or above the current U.S. Public Health Service recommended level for fluoridated water. In one analysis, lower fluid cognition scores were seen after about 675 micrograms per liter, which is close to the current recommended level of 700 micrograms per liter. The current regulatory level set by EPA is higher at 4,000 micrograms per liter. Above 675 micrograms per liter, each 500 micrograms per liter increase in fluoride was associated with an average 3.36-point lower score on the standardized fluid cognition scale.

The results were clearer for fluid cognition than for crystallized cognition, which includes learned knowledge such as vocabulary. The study did not find the same consistent pattern between higher fluoride levels and lower crystallized cognition scores across all children.

Children younger than 7 had larger differences in cognition scores linked to higher prenatal fluoride exposure, though more research is needed to understand why.

 

What was the study's impact?

This study adds to a large body of work that looks at how early exposure to environmental contaminants may be associated the development of the thinking and learning processes that are important for children’s developmental outcomes. Future research could focus on when children may be most sensitive to fluoride exposure and examine both potential developmental risks and dental health benefits to better understand relationships between fluoride exposure and child health. Because this was an observational study, the results show an association and do not prove that fluoride caused lower cognition scores.

 

Who was involved?

The study included 2,514 children from 17 ECHO Cohort Study Sites across 23 U.S. states. Children were born between 2006 and 2019 and completed cognition testing between ages 3 and 17.

 

What happened during the study?

Researchers estimated each child’s prenatal fluoride exposure by linking public water fluoride data to the mother’s residential address during pregnancy. They used monthly address information to estimate the average fluoride level in public drinking water during pregnancy. Children later completed NIH Toolbox cognition tests, which measured fluid cognition, crystallized cognition, and total cognition. Researchers then examined whether higher prenatal fluoride levels were related to differences in cognition scores, while accounting for factors such as child sex, birthing parent age and education, prenatal tobacco use, season of conception, and neighborhood characteristics.

The study focused on fluoride levels in public drinking water and did not measure total fluoride exposure from other sources such as toothpaste, tea, foods, supplements, bottled water, or private wells.

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 exposure to fluoride in public water and child cognition in the US ECHO Cohort, 2006-2019,” in American Journal of Epidemiology.

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

Published August 17, 2026

Read the related news release.

Read More Research Summaries

Higher Fluoride Levels in Public Drinking Water During Pregnancy May Be Linked to Differences in Children’s Cognition Scores, NIH-Funded Study Finds

Posted on by Jodi Snare

Pregnant woman having a glass of water

Associations appeared when fluoride levels in neighborhood drinking water were close to or above current U.S. recommended levels.

Pregnant mothers who lived in neighborhoods where public drinking water fluoride levels were near or above the current U.S. recommended levels, tended to have children who scored lower on tests of fluid reasoning as fluoride levels increased, according to a new study supported by the National Institutes of Health’s Environmental influences on Child Health Outcomes (ECHO) Program.

Fluoride occurs naturally in some water sources and is commonly added to public water systems to help prevent cavities. The paper’s authors note that a recent National Toxicology Program review examined evidence linking fluoride exposure levels above 1,500 micrograms per liter in drinking water with lower IQ scores in children. However, most U.S. public water systems have lower fluoride levels, and questions remain about associations at lower levels typically found in the United States.

ECHO researchers looked at whether fluoride levels in public drinking water during pregnancy were related to cognitive scores assessed during childhood.

"This study addresses an important gap by evaluating prenatal water fluoride and child cognition in a large U.S. sample," said lead author Katrina Simon, PhD, of Columbia University Mailman School of Public Health. "Findings from this work offer evidence that can inform ongoing guidance aimed at supporting children's development."

Researchers reported that children whose mothers had higher estimated fluoride levels in public drinking water during pregnancy tended to score lower on tests of fluid cognition that include problem-solving, memory, attention, and the ability to adapt to new information. Higher water fluoride levels were only linked to lower fluid cognition scores when water fluoride levels were near and above 675 micrograms per liter, which is close to the current U.S. Public Health Service recommended level of 700 micrograms, or 0.7 milligrams, per liter for fluoridated water. The current regulatory level set by EPA is higher at 4,000 micrograms per liter. Above 675 micrograms per liter, each 500 micrograms per liter increase in fluoride was associated with an average 3.36-point lower score on the standardized fluid cognition scale.

Researchers also found that the relationship between prenatal fluoride levels and cognition was specific to fluid cognition. Importantly, the study did not identify a link between fluoride and crystallized cognition, which includes learned knowledge such as vocabulary, across all ages.

In addition, the associations appeared stronger when cognition was assessed at a younger age. Children younger than 7 years of age showed larger differences in cognition scores associated with higher prenatal fluoride exposure compared to older children. Additional research is needed to better understand these age-related findings.

The study included 2,514 children born between 2006 and 2019 who completed cognitive testing between ages 3 and 17.

To estimate prenatal water fluoride exposure, researchers linked publicly available drinking water fluoride measurements to residential address information collected during pregnancy from ECHO participants. The study focused specifically on fluoride levels in public drinking water systems and did not measure total fluoride exposure from all possible sources, such as toothpaste, tea, foods, supplements, bottled water, or private wells.

Researchers then compared these estimates with children's performance on NIH Toolbox cognition assessments, while accounting for factors such as parental education, parental age, prenatal tobacco exposure, child sex, season of conception, and neighborhood characteristics.

“Because our study used fluoride measurements from public water systems that are collected as part of routine drinking water monitoring, the findings may help inform future evaluations of public drinking water guidelines,” said co-senior author Anne Nigra, PhD, also of Columbia University Mailman School of Public Health.

Community water fluoridation has long been used as a public health measure intended to reduce tooth decay. The current study does not evaluate the overall benefits and risks of community water fluoridation

“This study adds to a large body of work that looks at how early exposure to environmental contaminants may be associated with the development of the thinking and learning processes that are important for children’s developmental outcomes,” said co-senior author Amy Margolis, PhD, of The Ohio State University Wexner Medical Center and College of Medicine. “Continuing to study fluoride and other exposures will be integral in best supporting children’s environmental health and well-being.”

The researchers emphasize that this was an observational study. The findings demonstrate an association between prenatal fluoride exposure and children's cognition, but they do not prove that fluoride caused differences in cognitive performance.

The authors noted that future research could focus on when children may be most sensitive to fluoride exposure and examine both potential developmental risks and dental health benefits to better understand relationships between fluoride exposure and child health.

This collaborative research was published in the American Journal of Epidemiology.

Simon KR, Bloomquist TR, Rajeev T, Hernandez A, Kulali S, Burjak M, Kress AM, Palmore M, Akbaryan A, Sanchez TR, Ornelas Van Horne Y, Shin HM, Goin DE, Tamayo-Ortiz M, Patel GH, Shuffrey LC, Ghassabian A, Karagas MR, Leventhal L, Fry RC, Miller RL, Herbstman J, Morales S, Margolis AE, Nigra AE. Prenatal exposure to fluoride in public water and child cognition in the US ECHO Cohort, 2006-2019. 2026. American Journal of Epidemiology. https://doi.org/10.1093/aje/kwag186

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.

Connect With Us

echo connector

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.

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

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Pre-, Peri-, and Postnatal

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

Posted on 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.

Connect With Us

echo connector

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.

ECHO Study Finds No Strong Overall Link Between Exposure to Gas Stoves, Mold, or Water Damage During Pregnancy and Birth Outcomes

Posted on by Jodi Snare

Having a gas stove, mildew or mold, or water damage in the home during pregnancy was not associated with shorter pregnancy duration or lower birth weight, according to a recent ECHO Cohort study led by Deborah Bennet, PhD, and Jiwon Oh, PhD, of University of California, Davis.

While outdoor air pollution has been linked to adverse birth outcomes such as preterm birth and low birth weight, less is known about the effects of common indoor household exposures during pregnancy such as gas stoves, mold or mildew, and water damage. These exposures can contribute to indoor air pollution or damp conditions that may affect maternal and fetal health.

Overall, the results of this study found no strong overall link between these household exposures and outcomes like preterm birth or birth weight, when looking at the full study population. Using kitchen ventilation, such as a hood or fan, also did not appear to change these results.

However, some differences were seen in certain groups. For example, mold or mildew and water damage were linked to a higher likelihood of early term birth (37-38 weeks) in homes built after 1980, and mold exposure was associated with a higher chance of preterm birth among mothers with higher education. Other patterns varied by race and ethnicity.

These findings suggest that indoor air quality during pregnancy may not have a strong association with birth outcomes overall, but that housing and social factors may influence how these exposures affect health.

“Although the presence of gas stoves, mold, or water damage in the home during pregnancy was not associated with adverse birth outcomes in this population-based study, frequent ventilation through windows or doors is recommended to reduce exposure to potentially harmful indoor air pollutants,” said Dr. Bennett.

Researchers say future studies could provide more details about indoor conditions, including how often gas stoves are used, how well homes are ventilated, and how severe mold or water damage may be.

This collaborative research, titled “Prenatal Exposure to Gas Stoves, Mold, and Water Damage: Associations With Gestational Duration and Fetal Growth in the ECHO Cohort,” is published in Environmental Pollution.

ECHO Study Finds No Strong Overall Link Between Exposure to Gas Stoves, Mold, or Water Damage During Pregnancy and Birth Outcomes

ECHO Study Finds No Strong Overall Link Between Exposure to Gas Stoves, Mold, or Water Damage During Pregnancy and Birth Outcomes

Authors: Jiwon Oh, Deborah Bennet, 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?

Environmental exposures during pregnancy can affect fetal growth and length of pregnancy. While outdoor air pollution has been linked to adverse birth outcomes such as preterm birth and low birth weight, less is known about the effects of common indoor household exposures during pregnancy such as gas stoves, mold or mildew, and water damage. These exposures can contribute to indoor air pollution or damp conditions that may affect maternal and fetal health. ECHO researchers wanted to better understand whether these common household conditions during pregnancy are associated with the duration of pregnancy or fetal growth in a large, diverse U.S. population.

 

What were the study results?

Overall, having a gas stove, visible mold or mildew (outside of showers or bathtubs), or water damage in the home during pregnancy was not associated with shorter pregnancy duration or lower birth weight. Some differences appeared in subgroup analyses, particularly by home age, but these findings were secondary and should be interpreted with caution. Mold or mildew and water damage were associated with a higher likelihood of early term birth (37–38 weeks) in homes built after 1980, a pattern not seen in older homes. Use of kitchen ventilation (such as a hood or fan) did not appear to change the relationship between gas stove use and birth outcomes.

 

What was this study's impact?

These findings suggest that indoor air quality during pregnancy may not have a strong association on birth outcomes overall. Because housing conditions and other life circumstances can shape how environmental exposures affect pregnancy, these results underscore the importance of looking at the bigger picture when studying possible health risks.

 

Who was involved?

The study included 11,483 mother–infant pairs from 31 ECHO Cohort Study Sites across the United States. Births occurred between 2000 and 2023, with most occurring after 2016. The study brings together data from people living in many parts of the U.S. and from a wide range of backgrounds.

 

What happened during the study?

Mothers reported whether they had a gas stove, visible mold or mildew, or water damage in the home where they lived for most of their pregnancy. Researchers used medical records and reports to measure pregnancy length and infant birth weight. Statistical models were used to examine whether these household exposures were associated with length of pregnancy or fetal growth, while accounting for factors such as maternal age, education, race and ethnicity, smoking during pregnancy, and pregnancy-related health conditions.

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 studies could build on these findings by collecting more detailed information about indoor environmental conditions, such as how often gas stoves are used, ventilation effectiveness, and the location and severity of mold or water damage. Additional research may also help clarify why certain groups or housing types appear to show a stronger association.

 

Where can I learn more?

Access the full journal article, titled “Prenatal Exposure to Gas Stoves, Mold, and Water Damage: Associations With Gestational Duration and Fetal Growth in the ECHO Cohort,” in Environmental Pollution.

 

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

 

Published June 15, 2026

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Fertility Challenges Associated with Small Differences in Children’s Neurodevelopment, NIH Study Finds

Posted on by Jodi Snare

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Difficulty conceiving a pregnancy may be associated with small differences in children’s learning and behavior, according to a new study funded by the Environmental influences on Child Health Outcomes (ECHO) Program at the National Institutes of Health (NIH).

Neurodevelopmental differences in childhood, including behavioral concerns and conditions such as autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD), can affect long-term health and well-being. As more families use fertility treatments, researchers are working to understand whether these treatments—or the underlying fertility challenges that preceded them—may be linked to children’s development. Previous studies have often been small or unable to separate the effects of infertility from the effects of treatment.

To address these gaps, researchers analyzed data from the ECHO Cohort, examining how fertility history and fertility treatments were related to children’s neurodevelopment. The study included 15,382 mother–child pairs from 44 study sites across the U.S., including Puerto Rico. Researchers combined survey data and medical records to categorize pregnancies by fertility history, including infertility diagnoses, fertility treatments, multiple miscarriages, and extended time trying to conceive. Children’s development between ages 2 and 10 was assessed using parent-completed questionnaires and reports of clinician diagnoses of ASD and ADHD.

In this study, children of parents with fertility challenges showed slightly higher behavior-problem scores, slightly more autism-like traits, and higher odds of an ASD diagnosis, even when conceived without fertility treatment. The study also found an association between children conceived using non–in vitro fertilization (IVF) fertility treatments had higher odds of ADHD compared with those conceived naturally. However, researchers did not find clear evidence that IVF itself was associated with neurodevelopmental outcomes.

Key takeaways include:

  • Parental fertility challenges were associated with small differences in children’s behavioral and developmental outcomes.
  • Conception using non-IVF fertility treatments was associated with higher odds of ADHD.
  • IVF was not clearly associated with neurodevelopmental outcomes in this study.

“This study contributes to the growing body of evidence indicating that infertility treatment itself is not independently associated with child neurodevelopment outcomes,” said ECHO researcher Linda Kahn, PhD, of NYU Langone Health. “Rather, it appears that the parents’ underlying fertility problems—whether stemming from genetic, environmental, or other influences—are likely driving these associations.”

This collaborative research, titled “Associations of subfecundity and infertility treatment with child neurodevelopment in ECHO,” is published in JAMA Network Open.

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.

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