Exposure to Common Flame-retardant Chemicals During Pregnancy May Be Associated with Behavioral Issues in Young Children, ECHO Study Finds

Author(s): Jiwon Oh, 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?

Organophosphate esters (OPEs) are chemicals commonly used as flame retardants and plastic softeners in a variety of household and industrial products, including furniture, electronics, infant products, and fabrics. Previous research has linked exposure to OPEs during pregnancy with potential adverse effects on child brain development, but more evidence is needed. In this study, researchers investigated the association between prenatal exposure to OPEs and child behaviors.

What were the study results?

Among the nine OPEs measured, diphenyl phosphate (DPHP) was detected in almost all pregnant women (99.5%) and had the highest median concentration. Other frequently detected OPEs included dibutyl phosphate/di-isobutyl phosphate (DBUP/DIBP), bis (1,3-dichloro-2-propyl) phosphate (BDCPP), bis(2-chloroethyl) phosphate (BCETP), bis(2-butoxyethyl) phosphate (BBOEP), and bis(1-chloro-2-propyl) phosphate (BCPP).

Prenatal exposure to BBOEP (at moderate concentrations rather than high concentrations) was associated with more internalizing behaviors (e.g., anxiety, depression, emotional reactivity), externalizing behaviors (e.g., aggression, inattention), and total behavior issues in young children. Exposure to BCPP was associated with more externalizing behaviors and total behavior issues. In contrast, detectable dipropyl phosphate (DPRP) was associated with slightly fewer externalizing behaviors. Boys showed more behavior issues associated with prenatal BDCPP and BCPP exposure. Children from highly vulnerable neighborhoods—defined by community-level demographics, socioeconomic status, housing, access to transportation, and other factors—exhibited more behavior issues associated with prenatal BCPP exposure.

What was the study's impact?

Use of OPEs is increasing, with widespread exposure observed in pregnant women. While further research is needed, this study suggests that reducing exposure to certain chemicals during pregnancy may help mitigate emotional and behavioral problems in young children.

Who was involved?

The study included 2,948 mother–child pairs from 12 ECHO Cohort study sites across the United States. Non-Hispanic White (40.2%), non-Hispanic Black (28.6%), and Hispanic (21.3%) mothers were included in the study. Most participating mothers (85.2%) did not experience major pregnancy complications and most of their children (93.2%) were born after at least 37 weeks of pregnancy.

What happened during the study?

During the study, researchers collected urine samples from pregnant participants and analyzed them for nine chemical markers of OPE exposure. Later, researchers assessed the child’s behaviors using the Child Behavior Checklist for Ages 1½–5. The researchers then used statistical methods to examine associations between each OPE exposure during pregnancy and behavioral issues in children. The study also evaluated how other factors, like the child’s sex and their social vulnerability, may have influenced the effect of prenatal OPE exposure on their behavior.

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 help researchers better understand the effects of prenatal OPE exposure on child brain development and determine whether reducing these exposures could be beneficial to children’s health and development.

Where can I learn more?

Access the full journal article, titled “Prenatal Exposure to Organophosphate Ester Flame Retardants and Behavioral Outcomes in Early Childhood in the Environmental influences on Child Health Outcomes (ECHO) 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 August, 2025

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Exposure to Common Flame-retardant Chemicals During Pregnancy May Be Associated with Behavioral Issues in Young Children, ECHO Study Finds

ECHO Study Finds Exposure to Phenols During Pregnancy Associated with Changes in Non-Nutritive Suck Patterns in Infants

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ECHO Study Finds Exposure to Phenols During Pregnancy Associated with Changes in Non-Nutritive Suck Patterns in Infants

Authors: Megan Woodbury, Andréa Aguiar, Emily Zimmerman, 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?

During this study, researchers evaluated the relationship between exposure to phenols—chemicals used in a variety of consumer products and industrial processes that can disrupt hormones—during pregnancy and non-nutritive sucking patterns in infants. Non-nutritive sucking is a common behavior during infancy where a baby may suck on an object that cannot provide nutrients, such as a pacifier. Non-nutritive sucking is characterized by bursts of sucking separated by pauses to breathe. Researchers can measure the frequency, speed, and strength of non-nutritive sucking. Because sucking is a behavior present from birth that is controlled by neurons in the brainstem, it is an ideal indicator of early brain development. Previous studies have indicated that non-nutritive sucking patterns can be affected by environmental exposures during pregnancy. Understanding this relationship could provide insights into how prenatal chemical exposures impact early neurodevelopment.

What were the study results?

The study found that phenol exposure during pregnancy was linked to changes in non-nutritive suck patterns in infants. Specifically, exposure to Bisphenol F, a common alternative to Bisephenol A or BPA found in some food packaging, was related to a lower non-nutritive suck frequency. Alternatively, exposure to Triclosan, an antimicrobial chemical found in some soaps, was associated with a higher non-nutritive suck frequency. Exposure to other phenols used as preservatives and industrial processes (propylparaben, 2,4-dichlorophenol, and 2,5-dichlorophenol) was associated with weaker non-nutritive suck. Exposure to some phenols used in sunscreens and industrial processes (benzophenone-3, 2,4-dichlorophenol, and 2,5-dichlorophenol) were related to more non-nutritive suck bursts per minute. Propylparaben, a chemical used in some preservatives, was associated with more non-nutritive sucking per burst.

What was this study's impact?

This study provides additional evidence that exposure to phenols may affect early brain development. Continued research into the effects of pregnancy exposures on infant health and development can help inform strategies for reducing potentially harmful exposures.

Who was involved?

The study included 215 mother-infant pairs from two ECHO Cohort study sites: the Illinois Kids Development Study (IKIDS) and ECHO in Puerto Rico (ECHO-PROTECT).

What happened during the study?

During the study, researchers measured phenol exposure by analyzing phenol levels in maternal urine samples collected during pregnancy. Non-nutritive sucking was evaluated in 1- to 8-week-old infants using a custom pacifier for approximately 5 minutes. Statistical methods were used to investigate how exposure to 11 different phenols and triclocarban—another chemical used as an antibacterial agent in some soaps—affected non-nutritive suck, adjusting for factors like study site, child sex and assessment age, and maternal age and education.

What happens next?

Future studies could help clarify why non-nutritive suck patterns change in response to certain pregnancy exposures and how these changes might affect the baby's brain development as they grow.

Where can I learn more?

Access the full journal article, titled “Examining the association between prenatal Phenol exposure and infant non-nutritive suck in two ECHO Cohorts,” in Environmental 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 2025

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ECHO Study Finds Exposure to Phenols During Pregnancy Associated with Changes in Non-Nutritive Suck Patterns in Infants

Prenatal Exposure to Phthalates, But Not Phthalate Replacements, Linked to Children’s Behavior, ECHO Study Finds

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Prenatal Exposure to Phthalates, But Not Phthalate Replacements, Linked to Children’s Behavior, ECHO Study Finds

Author(s): Jiwon Oh, 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?

Phthalates are widely used chemicals that make plastics more flexible. During pregnancy, these chemicals can cross the placenta and may affect brain development. Although exposure to some phthalates has decreased over the past two decades, these chemicals and their replacements—such as DINCH and DEHTP—are still common, and little is known about their effects on children’s brain development. In this study, researchers examined many chemicals that form when the body breaks down phthalates and other plasticizers to see if exposure to these chemicals during pregnancy might be associated with behavioral problems in young children, including emotional reactivity, anxiety, depression, aggression, and attention problems.

What were the study results?

Researchers found that higher levels of two phthalate metabolites, mono-benzyl phthalate (MBzP) and mono-hexyl phthalate (MHxP), during pregnancy were associated with small to modest increases in externalizing behaviors (aggression and attention problems) in children aged 1.5–5 years. They did not find strong links between phthalate exposure and internalizing behaviors (emotional reactivity, anxiety, and depression), or between prenatal exposure to the phthalate replacement DINCH and any behavioral outcomes. The impact of these chemicals varied between boys and girls and depended on the neighborhood where the children lived. Some chemicals had stronger associations in kids from neighborhoods with more resources, while others were more impactful in areas with fewer resources.

What was the study's impact?

The study suggests that prenatal exposure to certain phthalates, but not to the alternative chemical DINCH, may be associated with increased externalizing behaviors in young children.

Who was involved?

Participants included 2,617 mother–child pairs from 13 ECHO Cohort study sites. Children’s behaviors were assessed at ages 1.5–5 years, and maternal urine samples were collected mostly during mid- to late-pregnancy.

What happened during the study?

During the study, prenatal maternal urine samples were analyzed for 27 chemical markers of phthalate exposure and six markers of exposure to non-phthalate replacements. Later, the children's behaviors were assessed using the Child Behavior Checklist for Ages 1½–5 (CBCL/1½–5). The researchers then used statistical methods to explore how levels of specific chemicals in the pregnant women’s body were linked to behaviors like emotional reactivity, anxiety, depression, aggression, and attention problems, and whether these links differed by child sex and neighborhood opportunity.

What happens next?

Future studies could show how much pregnant women are exposed to di-n-hexyl phthalate (the parent compound of MHxP) and its effects on children’s brain development across different populations. Researchers may also study how different newer plasticizers affect brain development by looking at more recent participants and testing samples taken from mothers at several stages during pregnancy.

Where can I learn more?

Access the full journal article, titled “Prenatal exposure to phthalates and alternative plasticizers and emotional and behavioral outcomes in early childhood in the Environmental influences on Child Health Outcomes (ECHO) 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 August, 2025

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Prenatal Exposure to Phthalates, But Not Phthalate Replacements, Linked to Children’s Behavior, ECHO Study Finds

ECHO Study Observes Health Disparities in Air Pollution-associated Risk of Childhood Asthma

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ECHO Study Observes Health Disparities in Air Pollution-associated Risk of Childhood Asthma

Authors: Veronica A. Wang, Rima Habre, Diane R. Gold, Antonella Zanobetti, 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?

Asthma is one of the most common chronic childhood diseases in the United States, affecting over 4.5 million children. Although air pollution levels have decreased over the past decades, individuals living in certain areas have seen lower reductions in air pollution and may also be more vulnerable to its effects. For this study, researchers examined sociodemographic disparities in the association between air pollution and incident childhood asthma until age 10.

What were the study results?

The study found that higher exposures to fine particulate matter, nitrogen dioxide, and ground ozone were associated with a higher incidence of asthma in the first 10 years of a child’s life. For fine particulate matter and nitrogen dioxide, children from areas with a higher proportion of Black residents or higher population density were identified being at a higher risk for air pollution-associated asthma.

What was the study's impact?

This study showed that sociodemographic disparities in air pollution-associated asthma persist despite reductions in the overall air pollution levels. The study highlighted the potential to mitigate childhood asthma risk by reducing air pollution and addressing the root causes of these disparities.

Who was involved?

The study involved over 23,000 children, born between 1981-2021, from 34 sites in the Environmental influences on Child Health Outcomes (ECHO) Program with data on asthma diagnosis until age 10 in the contiguous US.

What happened during the study?

During the study, the study team collected data on each participant’s asthma status, month of diagnosis, and length of their follow-up. They also collected sociodemographic data that included sex, race/ethnicity, maternal education, and more. Lastly, they used area-level data from the 1980-2019 Census Bureau and the American Community Survey on the percent of low-income residents, Black residents, residents with less than a high school education, unemployed residents, and female residents, and overall population density. The study team then analyzed this data, first examining the association between air pollution exposures (fine particulate matter, nitrogen dioxide, and ground ozone) and childhood asthma, then determining whether the sociodemographic and economic variables modified the air pollution-asthma association.

What happens next?

Future studies could help researchers better understand the root causes of susceptibility to air pollution. Additional studies with longer follow-up could also help researchers understand how asthma risk may change throughout childhood as the climate and environmental conditions change. Lastly, additional studies may help researchers understand how personal exposures affect asthma in children, including indoor sources of air pollution.

Where can I learn more?

Access the full journal article, titled “Disparities in the Association of Ambient Air Pollution with Childhood Asthma Incidence in the ECHO Consortium: a US-wide Multi-cohort Study,” in Environmental 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 2025

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ECHO Study Observes Health Disparities in Air Pollution-associated Risk of Childhood Asthma

Prenatal Vitamin D Levels Associated with Children’s Brain Development, ECHO Study Suggests

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Prenatal Vitamin D Levels Associated with Children’s Brain Development, ECHO Study Suggests

Authors: Melissa Melough, 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?

Vitamin D deficiency is one of the most common nutrient deficiencies in the world. In the U.S., it affects 80% of Black pregnant women and nearly half of pregnant women with incomes below the federal poverty level. Low vitamin D during pregnancy may harm childhood brain development, leading to lower academic achievement in adolescence. This study aimed to clarify how vitamin D levels during pregnancy may influence children’s brain development, particularly in varied groups and into later childhood. While prior research suggests prenatal vitamin D plays an important role in early brain development, few studies have examined whether these effects persist beyond early childhood or vary across groups that may be at higher risk for vitamin deficiencies. For example, Black people often have lower vitamin D levels because their skin has more pigment, which makes it harder for the skin to produce vitamin D from sunlight. Researchers sought to build on previous evidence by studying a varied cohort of mothers and their children, followed until ages 7 to 12.

What were the study results?

Researchers found that children whose mothers had higher vitamin D levels while pregnant tended to perform better on cognitive tests assessing skills like problem-solving and processing new information at ages 7 to 12. However, vitamin D levels were not linked to skills based on learned knowledge, such as vocabulary. The link between vitamin D and thinking skills was stronger in children of Black mothers compared to other racial groups. Results also suggested that vitamin D levels early in pregnancy were most important for children’s brain development. The largest differences in children’s cognitive skills—between those with the highest and lowest scores—were linked to their mothers’ vitamin D levels early in pregnancy, suggesting this may be a critical time for brain development.

What was the study's impact?

The study provides evidence that early pregnancy may be a critical period when vitamin D has the greatest potential to support brain development. Interventions prior to or earlier in pregnancy, and those focused on Black women and others at high risk of deficiency, may have the greatest impact.

Who was involved?

The study included 912 biological mother-child pairs from five ECHO Cohort research sites. Approximately 38% of participants were vitamin D-deficient.

What happened during the study?

Researchers measured vitamin D levels in pregnant women’s blood during pregnancy or in their babies’ cord blood at birth. They tested the children’s fluid and crystallized cognition when they were 7 to 12 years old using a standard set of cognitive tests. They analyzed how vitamin D levels during pregnancy were linked to children’s cognitive scores, while considering other factors that could affect the results. They also looked at whether certain times during pregnancy mattered more by comparing vitamin D levels across pregnancy in mothers of children with higher versus lower cognitive scores. This helped them identify when vitamin D might have the greatest impact on brain development.

What happens next?

Future research, including randomized trials, could help researchers identify the optimal dose and timing of vitamin D supplementation for children’s cognitive development.

Where can I learn more?

Access the full journal article, titled “Gestational vitamin D concentration and child cognitive development: a longitudinal cohort study in the Environmental influences on Child Health Outcomes Program,” 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 August 2025

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Prenatal Vitamin D Levels Associated with Children’s Brain Development, ECHO Study Suggests

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Children Living in Low-income Neighborhoods with Low Food Access at Higher Risk of Developing Asthma, ECHO Study Finds

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Children Living in Low-income Neighborhoods with Low Food Access at Higher Risk of Developing Asthma, ECHO Study Finds

Authors: Veronica Wang, Antonella Zanobetti, Diane Gold, Rima Habre, 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?

Asthma is characterized by chronic inflammation in the lungs, and prior research shows that a nutritious diet can reduce airway inflammation. However, access to affordable and healthy foods is often difficult for many communities that have limited access to supermarkets or grocery stores. In this study, the researchers wanted to learn whether residing in a low-income-low-food access neighborhood was associated with childhood asthma and whether this association was modified by sociodemographic factors.

What were the study results?

This study found that 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, with stronger associations observed in cumulative early childhood. The increased risk of asthma was more prominent among girls, Hispanic children, and children whose mothers had less than a high school education.

What was the study's impact?

This study demonstrates the importance of the neighborhood food environment to children’s respiratory health, particularly in early childhood. The findings suggest that food access in the immediate vicinity of residence and that vehicle access may be important and may contribute to disparities in childhood asthma development.

Who was involved?

The study included 16,012 children from 35 ECHO Cohort study sites, born between 1998 and 2021, from across the United States.

What happened during the study?

During the study, researchers collected information on participants’ residential addresses and whether they were diagnosed with asthma in cumulative early childhood (by age 5) or middle childhood (by age 11). Using the U.S. Department of Agriculture’s Food Access Research Atlas, the researchers evaluated whether each child lived in a low-income neighborhood that was within 0.5-1 mile of a supermarket (for urban areas) or 10-20 miles (for rural areas). They also evaluated whether each child lived in a low-income area where more than 100 households do not have a vehicle or a nearby supermarket. Using this data, researchers looked at how living in a low-income-low-food-access neighborhood might affect childhood asthma incidence. They also took into account factors like the child's sex, race/ethnicity, mother's education, whether the mother smoked during pregnancy, and whether the parents had asthma.

What happens next?

Additional studies could help researchers better understand how community access to healthy, nutritious foods affects asthma development. Future studies could also consider how other influences, such as the affordability of healthy foods and school-based food programs, might influence child health outcomes.

Where can I learn more?

Access the full journal article, titled “Residing in a low-income-low-food-access neighbourhood and asthma in early and middle childhood in the Environmental influences on Child Health Outcomes (ECHO) program: a multisite cohort study,” in BMJ Open.

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

Published June 30, 2025

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Children Living in Low-income Neighborhoods with Low Food Access at Higher Risk of Developing Asthma, ECHO Study Finds

Young Children May Be Exposed to a Variety of Emerging Chemicals Found in Some Consumer Products

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Young Children May Be Exposed to a Variety of Emerging Chemicals Found in Some Consumer Products

Author(s): Jiwon Oh, Deborah H. Bennett, 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?

Over time, exposure to chemicals like triclosan, parabens, phthalates, and PAHs became less common, likely because of new rules and bans on their use. However, replacement chemicals—like DINCH, a chemical that has replaced phthalates in some plastic products—and some pesticides have been showing up more often in later years. Exposure to multiple chemicals during pregnancy and early childhood is a concern because these are critical stages of development when children are more vulnerable to harm. Such exposures can increase their risk of health problems later in life. There is limited data tracking young children’s – 2 to 4 years - exposure to environmental chemicals compared to older children. Prenatal and early-life exposure to these chemicals can increase the risk of multiple adverse child health outcomes. This study aimed to investigate early childhood exposures to a variety of environmental chemicals.

What were the study results?

Scientists measured 111 different chemicals in urine samples from young children and their mothers during pregnancy. More than half of the samples contained chemicals such as environmental phenols, pesticides, phthalates, and chemical markers of exposure to polycyclic aromatic hydrocarbons (PAH). About 34 chemicals were found in over 90% of the total samples. Compared to their mothers during pregnancy, children had higher amounts of certain chemicals, like bisphenol S (BPS)—a chemical used in some hard plastics and synthetic fibers as a replacement for BPA—and pesticide-related compounds. On the other hand, mothers had higher levels of chemicals like triclosan and monoethyl phthalate (MEP), markers of exposure to chemicals found in some consumer products like soaps and cosmetics.

Certain groups of children, such as younger kids, later-born siblings, and those from families with fewer resources, were exposed to higher levels of chemicals.

What was the study's impact?

This study suggests that young children may be exposed to a variety of emerging and replacement chemicals that may affect their health later in life. Continued monitoring in larger populations of young children can help researchers better understand how these exposures affect children’s long-term health.

Who was involved?

The study included 201 children aged 2-4 years and their mothers recruited from six ECHO Cohort study sites across the United States.

What happened during the study?

Researchers collected urine samples from each child and their mother during pregnancy. These samples were analyzed for the levels of 111 different chemicals related to environmental exposures. The concentrations of these chemicals were compared between child and prenatal maternal samples. The researchers also examined social and environmental factors that may have influenced the concentration of each chemical in children's urine samples, such as race, ethnicity, maternal education, maternal age, and neighborhood opportunity.

What happens next?

Additional studies tracking early childhood exposures to a variety of contemporary and emerging chemicals could help researchers better understand the potential effects these exposures may have on children’s short and long-term health.

Where can I learn more?

Access the full journal article, titled “Exposures to Contemporary and Emerging Chemicals Among Children Aged 2-4 Years in the United States Environmental Influences on Child Health Outcomes (ECHO) Cohort,” in Environmental Science & Technology.

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

Published June 30, 2025

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Young Children May Be Exposed to a Variety of Emerging Chemicals Found in Some Consumer Products

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Adverse Birth Outcomes May be Associated with Arsenic Levels in Public Drinking Water

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Adverse Birth Outcomes May be Associated with Arsenic Levels in Public Drinking Water

Authors: Anne Nigra, 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?

Regulated U.S. public drinking water is a source of exposure to arsenic. Because arsenic occurs naturally, water that comes in contact with certain rocks and soils may contain it. Contamination from various industrial processes also contributes to increased levels of arsenic in some areas. Prenatal exposure to arsenic has been associated with adverse birth outcomes, including preterm birth and low birthweight. Researchers studied how arsenic in public drinking water—at levels below the federal limit—may affect birth outcomes in the ECHO Cohort. Previous evidence has been limited to private well exposures, studies using urinary biomarkers, and single-site studies with limited racial, ethnic, and geographic diversity.

What were the study results?

The study found that when pregnant women lived in areas with publicly reported high levels of arsenic in public drinking water, even at levels below the current federal safety standard of 10 micrograms per liter, their babies were more likely to be born with low birthweight (weighing less than 5 lbs 8 oz) or are small for their gestational age (smaller than babies born at the same number of weeks of pregnancy). These patterns were seen across several racial and ethnic groups, including White, Black, and Hispanic/Latino families. For example, babies born to Hispanic/Latino parents were about 40% more likely to have low birthweight with just a 5 microgram-per-liter increase in water arsenic. The study also found that babies born to Black parents had higher risks of being born early, with low birthweight, or smaller for their gestational age. Similar risks were observed among babies born to American Indian, Alaskan Native, Native Hawaiian, and Pacific Islander parents.

What was this study's impact?

The study shows that even low levels of arsenic in public drinking water may increase the risk of babies being born too early, too small, or underweight.

Who was involved?

Participants included 13,998 birthing mother-infant pairs from the ECHO Cohort.

What happened during the study?

Researchers estimated how much arsenic people were exposed to through public drinking water during pregnancy by combining water quality data with where each person lived each month. They then looked at whether that exposure was linked to outcomes like being born early (preterm birth), having a low birthweight, or being small for their gestational age.

What happens next?

Future research could help researchers understand how current efforts to reduce arsenic in drinking water are working—whether those efforts happen across the country, in local communities, in homes, or for individuals. Studies could also help identify where arsenic levels are highest, which may support ongoing work to make sure communities have safe drinking water.

Where can I learn more?

Access the full journal article, titled “Public water arsenic and birth outcomes in the Environmental influences on Child Health Outcomes Cohort,” 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 June 16, 2025

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Adverse Birth Outcomes May be Associated with Arsenic Levels in Public Drinking Water

A Diet High in Refined Grains and Low in Whole Grains in Pregnancy Linked to Lower Birthweights and Pre-term Births

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A Diet High in Refined Grains and Low in Whole Grains in Pregnancy Linked to Lower Birthweights and Pre-term Births

Analyzing Diets Based on Racial and Ethnic Groups May Better Predict Outcomes

Authors: Luis E. Maldonado, 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?

Researchers wanted to understand how a pregnant person’s diet, especially in relation to their blood sugar levels (fasting blood glucose), affects birth outcomes—like the baby’s weight and whether the baby is born early. Higher fasting blood glucose during pregnancy is known to increase the risk of adverse birth outcomes. However, little is known about whether culturally influenced combinations of foods and beverages play a meaningful role across different racial and ethnic groups. This question is important because, in the U.S., Hispanic pregnant women are disproportionately affected by adverse birth outcomes, such as preterm birth and low birthweight (under 5.5 pounds). By examining dietary patterns within racial and ethnic groups, the researchers aimed to uncover more precise links between diet and birth outcomes. These links might be overlooked when analyzing the population as a whole, since average diets often reflect the eating patterns of the most represented groups in the study.

What were the study results?

Refined grains, such as white bread or white rice, showed the strongest association with higher fasting blood sugar levels among Hispanic and non-Hispanic White women. People who ate diets high in refined grains and low in whole grains were more likely to have babies born with low birthweight, smaller for gestational age, or born preterm.

When dietary patterns were analyzed by racial and ethnic group, the associations between diet, blood sugar, and birth outcomes were stronger than when using a single pattern for the full population. In the group that included non-Hispanic White and Hispanic participants, nuts, seeds, and solid fats such as butter and lard were linked to lower blood sugar. Among non-Hispanic White participants, whole grains and solid fats had the strongest association with improved blood sugar control. In contrast, among Hispanic participants, higher fruit consumption was associated with elevated blood sugar levels. These food-specific associations should be considered within the overall dietary pattern, as individual foods can influence blood sugar – beneficially or adversely – within the broader diet.

What was the study's impact?

The results of this study show the importance of looking at dietary patterns within racial and ethnic groups, particularly in studies with varying representation of different racial and ethnic populations. Analyzing a single, combined group may mask group-specific associations between diet and birth outcomes, as the effects of diet can differ across racial and ethnic backgrounds.

Who was involved?

The study included 420 Hispanic and 564 non-Hispanic White pregnant participants from two ECHO Cohort study sites.

What happened during the study?

During the study, participants shared details about what they ate over a 24-hour period. The researchers analyzed the diets, along with the mother’s blood sugar, to help determine which combinations of foods eaten together in an overall diet are most closely linked to changes in blood sugar levels. They then tested whether the links between diet and birth outcomes were different across racial and ethnic groups by comparing findings from diets derived using group-specific versus combined fasting blood glucose, which have also been previously shown to vary by racial and ethnic population.

What happens next?

Future research could continue exploring how dietary patterns affect birth outcomes in diverse populations, especially by identifying patterns that are specific to different racial and ethnic groups.

Where can I learn more?

Access the full journal article, titled “Racial/Ethnic-Derived Maternal Diets Predict Birth Outcomes Better than a Diet Derived from a Combined Sample among Hispanic/Latina and non-Hispanic White Pregnant Individuals in the ECHO Cohort,” in Nutrition.

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

Published June 12, 2025

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A Diet High in Refined Grains and Low in Whole Grains in Pregnancy Linked to Lower Birthweights and Pre-term Births

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Pregnancy and birth

Prenatal Exposure to Air Pollution Associated with Higher Risk for Autism-related Outcomes, ECHO Study Finds

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Prenatal Exposure to Air Pollution Associated with Higher Risk for Autism-related Outcomes, ECHO Study Finds

Author(s): Heather Volk, Akhgar Ghassabian, 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?

Air pollution is a significant environmental health concern and contributes to many illnesses and early deaths worldwide. Ambient air pollution can have detectable effects on the brain. Recent studies show that being exposed to air pollution during pregnancy and early life can affect how a child’s brain develops. This can happen through several pathways, such as causing inflammation in the brain, disrupting hormones, or changing how genes work. Previous research has suggested potential links between air pollution and neurodevelopmental disorders, but the relationship between exposure to air pollution, even at low levels, during pregnancy and ASD has been unclear. This study examined the associations between prenatal air pollution exposure and autism spectrum disorder (ASD) in children.

What were the study results?

The study team observed that higher prenatal exposure to ozone was associated with autism-related traits and increased risk of ASD diagnosis. Exposure to fine particulate matter (PM_2.5) and nitrogen dioxide was also associated with a higher risk of autism, but associations varied by geographical regions. There was little evidence for differences between boys and girls in the association between prenatal air pollution exposure and autism outcomes.

What was the study's impact?

The study's findings suggest that even low levels of air pollution exposure during pregnancy might be associated with autism-related outcomes. This highlights the importance of understanding the risks associated with air pollution exposure during pregnancy and its effects on child neurodevelopment.

Who was involved?

The study involved 8,035 mother-child pairs from 44 ECHO study sites across the United States. This sample included over 1,000 child participants who were potentially at higher risk for ASD due to being born preterm or having siblings with autism. The remaining participants were recruited from samples representative of the general population.

What happened during the study?

This study looked at scores from the Social Responsiveness Scale (SRS), a parent-report tool that measures autism-related traits in children, with higher scores indicating higher autism-related traits. During the study, researchers estimated daily exposure to particulate matter, nitrogen dioxide, and ozone at the residential addresses of pregnant women. They then analyzed the associations between these air pollutants and autism-related traits using the Social Responsiveness Scale (SRS) and physician-diagnosed ASD.

What happens next?

The study results suggest that even small changes in prenatal air pollution exposure could have a significant impact on child neurodevelopment. Future studies are needed to understand why these connections exist and to look at the impact of specific air pollution components.

Where can I learn more?

Access the full journal article, titled “Prenatal Air Pollution Exposure and Autism Spectrum Disorder in the ECHO Consortium,” in Environmental Health Perspectives.

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

Published June 11, 2025

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Prenatal Exposure to Air Pollution Associated with Higher Risk for Autism-related Outcomes, ECHO Study Finds