Author: Jodi Snare

Wildfire Smoke Exposure During Pregnancy Linked to Higher Risk of Preterm Birth, ECHO Study Finds

Posted on by Jodi Snare

Study highlights increased risk, especially in Western states and during intense smoke events

Exposure to wildfire smoke during pregnancy was associated with a higher risk of preterm birth, especially in the Western United States and during periods of intense or prolonged smoke, according to a study funded by the National Institutes of Health’s Environmental influences on Child Health Outcomes (ECHO) Program.

Wildfires are becoming more frequent and severe, raising concerns about their impact on public health. While previous studies suggested a link between wildfire smoke and preterm birth, ECHO’s research built on this by studying a diverse population from prospective cohort sites nationwide. Researchers also looked closely at the role of exposure intensity, duration, and timing.

“Our study adds to growing evidence that wildfire smoke is a concern for maternal and child health. Incorporating wildfire smoke considerations into prenatal care and public health guidance could help expecting parents protect themselves during smoke events, especially in areas where wildfires are common,” said Allison Sherris, PhD, of the University of Washington.

Researchers analyzed data from over 20,000 births between 2006 and 2020 at 30 study sites across the U.S. They matched daily levels of air pollution from wildfire smoke (fine particulate matter, or PM2.5) to each participant’s home address during pregnancy. They tracked both the average amount of smoke and the number of “smoke days,” as well as “smoke waves”—stretches of consecutive days with high smoke levels.

The team used statistical methods to compare pregnancies week by week and adjusted for many factors, including maternal age, race, ethnicity, neighborhood poverty, season of conception, birth year, and more.

Key Findings

  • Widespread Exposure: Nearly all pregnant participants (99.2%) experienced at least one day of wildfire smoke, with an average of 22 smoke days during pregnancy.
  • Preterm Birth Risk: The overall rate of preterm birth was 8.4%, with higher rates among Black (11.7%) and American Indian or Alaska Native (13.5%) participants compared to White (7.6%) and Asian, Native Hawaiian, or Pacific Islander (8.0%) participants.
  • Link Between Smoke and Preterm Birth: For every 1 microgram per cubic meter (µg/m³) increase in average wildfire PM2.5 during pregnancy, the odds of preterm birth increased by about 7%. The association was even stronger in the Western U.S., where wildfire smoke is more intense and frequent.
  • Intensity and Duration Matter: The risk of preterm birth was higher with more intense smoke and longer-lasting smoke events. The strongest associations were seen for mid-pregnancy exposure to lower levels of smoke and late-pregnancy exposure to high-intensity smoke days.
  • Critical Windows of Vulnerability: Certain periods during pregnancy—especially mid-pregnancy for lower-intensity smoke and late pregnancy for high-intensity smoke—were linked to the greatest risk increases for preterm birth.

“Preterm birth has strong implications for future child health. Better understanding of how to prevent preterm birth will pay off as a healthier population into the future,” said Catherine Karr, MD, PhD, of the University of Washington.

The study points to the need for more research on why some regions or groups may be more affected, how wildfire smoke combines with other risks like extreme heat, and which prevention strategies work best. It also highlights the importance of public health agencies and healthcare providers offering ways to help keep pregnant people safe during wildfire events.

This collaborative research was published in The Lancet Planetary Health.

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 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

echo connectorCheck 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.

PFAS Exposures During Pregnancy Not Significantly Associated with Child Behavior Issues

Posted on by Jodi Snare

Exposure to per- and polyfluoroalkyl substances (PFAS) during pregnancy was not significantly associated with behavior issues in children, according to a new ECHO Cohort study led by Catherine Bulka, PhD of the University of South Florida and Rebecca Fry, PhD of the University of North Carolina, Chapel Hill.

PFAS are man-made chemicals used in some consumer and industrial products like cookware, stain-resistant fabrics, and foams used to fight fires. They are often referred to as “forever chemicals” because they don’t break down easily, causing them to build up in water, soil, and air. Previous findings on the effects of prenatal PFAS exposure on child behavior have been inconclusive due to small sample sizes, limited exposure variability, and differing measures of child behavior. This study included children from nine ECHO Cohort study sites across the United States, including 1,723 preschool-age children (1.9-5.9 years) and 627 school-age children (6-15 years). Researchers measured mothers’ PFAS exposure through blood samples collected during pregnancy (between 2- and 42-weeks’ gestation) and assessed children’s behavior using the Child Behavior Checklist (CBCL).

Key Takeaways include:

  • Most of the PFAS detected in pregnant mothers were not clearly linked to behavior problems in their children overall.
  • Children whose mothers had medium levels of exposure to perfluorohexane sulfonate (PFHxS) during pregnancy showed more emotional problems, like being easily upset or withdrawn, especially when they were preschoolers. This pattern was not seen at very high or low levels of PFHxS exposure.
  • There were no strong connections between PFAS exposure before birth and behavior problems when the children were older (school-age).
  • Looking at combined exposures to multiple PFAS also did not show any clear relationship with child behavior.

“While most PFAS showed no association with behavioral problems, some suggestive, non-linear relationships emerged, indicating that these exposures may influence neurodevelopment in complex and unexpected ways,” said Dr. Bulka.

Additional studies could help researchers assess the effects of PFAS exposure during the postnatal period, which may be a more relevant window for childhood brain development and behavioral issues. Also, as some PFAS are being phased out of consumer products and replacements are emerging, future studies could help researchers understand the potential effects of exposures to these newer replacement chemicals.

This collaborative research, titled “Prenatal Exposure to Per- and Polyfluoroalkyl Substances: Association with Child Behavior in the Environmental influences on Child Health Outcomes (ECHO) Cohort,” is published in Environment International.

Read the research summary.

ECHO Awards More Than $13 Million for Intervention Research

Posted on by Jodi Snare

I am happy to announce that ECHO has made 19 awards totaling over $13 million for FY 2026 for the ECHO Institutional Development Award (IDeA) States Pediatric Clinical Trials Network (ISPCTN).

These awards support institutions located in 18 IDeA eligible states to serve as Clinical Sites and a Data Coordinating and Operations Center (DCOC) for the ISPCTN.

Each clinical site will:

  • Develop, conduct, and disseminate findings from multicenter pediatric clinical trials that ensure the participation of children living in rural or underserved communities in IDeA states;
  • Build pediatric clinical trial research capacity within these IDeA states;
  • Engage communities, nonprofit organizations, and professional societies to enhance clinical trial impact, transferability, rigor, and feasibility.

The DCOC will serve as the central hub for the ISPCTN, providing essential leadership and infrastructure for the network.

ECHO funded these awards after a competitive peer review process. View a list of awardees.

Matthew Gillman, MD, SM
Director of the ECHO Program

ECHO Awards More Than $13 Million for Intervention Research into Environmental Influences on Child Health

Posted on by Jodi Snare

The NIH Environmental influences on Child Health Outcomes (ECHO) Program is pleased to announce that it has made 19 awards totaling over $13 million for FY 2026 for the ECHO Institutional Development Award (IDeA) States Pediatric Clinical Trials Network (ISPCTN).

These awards support institutions located in 18 IDeA eligible states to serve as Clinical Sites and a Data Coordinating and Operations Center (DCOC) for the ISPCTN.

Each Clinical Site will:

  • Develop, conduct, and disseminate findings from multicenter pediatric clinical trials that ensure the participation of children living in rural or underserved communities in IDeA states;
  • Build pediatric clinical trial research capacity within these IDeA states;
  • Engage communities, nonprofit organizations, and professional societies to enhance clinical trial impact, transferability, rigor, and feasibility.

The DCOC will serve as the central hub for the ISPCTN, providing essential leadership and infrastructure for the network.

The Program Office congratulates these awardees and looks forward to collaborating with them as they conduct multicenter pediatric clinical trials across ECHO’s five outcome areas—pre, peri, and postnatal outcomes; upper and lower airways; obesity; neurodevelopment; and positive health.

ECHO funded these awards after a competitive peer review process. View a list of awardees.

ECHO Participants and Investigators Featured in The Washington Post

Posted on by Jodi Snare

The Washington Post recently featured the Environmental influences on Child Health Outcomes (ECHO) Program in a story on phthalates—chemicals commonly found in plastics and personal care products—and how they may affect babies’ development during pregnancy.

The article highlighted ECHO participants who are helping researchers understand how chemical exposures during pregnancy and throughout the life course may influence pregnancy outcomes and child health. ECHO participants Arica Nyamsi and Cassondra Perez shared a range of experiences with chemical exposures, from making significant lifestyle changes to expressing uncertainty and a need for clearer guidance.

Sheela Sathyanarayana, a professor of pediatrics at the University of Washington, explained that determining safe levels of phthalate exposure is challenging because individual health risks vary based on genetics and susceptibility.

The story also featured ECHO investigator Dr. Leonardo Trasande of NYU Grossman School of Medicine, who noted in the article:

“Endocrine-disrupting chemicals are one of the biggest global health threats of our time. And 2 percent of us know about it — but 99 percent of us are affected by it.”

Chemical exposures will be a focus at the ECHO Symposium: Translating Science to Action on September 15, 2025. During the first session, Dr. Trasande will discuss phthalate exposure in pregnancy and early childhood, focusing on the evidence, knowledge gaps, and opportunities to inform policies, practices, and programs. Mrs. Perez will also speak during the third session on her experience as an ECHO participant.

Learn more about ECHO’s ongoing research on chemical exposures. Also, review the full symposium agenda for details and register to attend this free event either in-person or virtually.

Toddlers Showed Slightly Fewer Behavioral Problems During COVID-19 Pandemic, NIH Study Finds

Posted on by Jodi Snare

Toddlers assessed during the COVID-19 pandemic had slightly fewer emotional and behavioral problems compared to children assessed before the pandemic, suggesting some toddlers may have shown resilience during this time. This finding comes from a study of over 3,000 children across the United States using data from the Environmental influences on Child Health Outcomes (ECHO) Cohort Consortium collected between September 2009 and July 2023.

The COVID-19 pandemic disrupted family patterns and children’s environments, both critical for early brain development and well-being. While earlier research raised concerns about infants born during the pandemic, there is limited information about how toddlers’ emotional and behavioral health might have been affected.

To explore this, the study examined data from 3,438 toddlers (average age of 2 years) across the U.S. and Puerto Rico. Researchers used the Preschool Child Behavior Checklist (CBCL), a parent-reported measure of child behavior and emotions, to compare children assessed before and during the pandemic.

Children were grouped based on when they were born and when their behavior was assessed: before the pandemic, born before but assessed after March 2020, or both born and assessed during the pandemic. Parents completed the CBCL, which asks about behaviors such as anxiety, sadness, and aggression. These reports helped researchers understand how growing up during the pandemic might have influenced toddler emotional and behavioral health.

Key findings include:

  • Children who experienced the pandemic had significantly lower scores for internalizing problems (such as anxiety and sadness) and externalizing problems (such as aggression or hyperactivity) compared to children assessed before the pandemic.
  • Internalizing problem scores were about 1.5 to 2 points lower, and externalizing problem scores were about 1.7 to 3.2 points lower than those born and assessed before the onset of the pandemic.
  • Although the differences were small, they were consistent. The associations were stronger among children whose mothers did not have a bachelor’s degree.

“Our findings suggest that even during periods of widespread pandemic-related disruption, toddler-aged children may have experienced opportunities for resilience,” said study author Anahid Akbaryan, a Research Associate at NYU Grossman School of Medicine. “Future research should explore within-home factors that may have supported child mental health outcomes during this time, such as consistent caregiving routines, household stability, and positive parental coping strategies to identify potential protective influences during times of instability.”

Study author Lauren Shuffrey, PhD, of NYU Grossman School of Medicine, added, “These findings suggest that some families may have adapted in ways that buffered young children from behavioral challenges during the pandemic, highlighting the importance of identifying and strengthening those protective supports.”

The researchers emphasized that further studies are needed to identify these protective factors and develop strategies to help families support child well-being during and after times of global disruptions.

This collaborative research 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.

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

echo connectorCheck 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.

Exposure to Certain Flame-retardant Chemicals During Pregnancy May Be Associated with Behavioral Issues in Young Children

Posted on by Jodi Snare

Exposure to certain organophosphate esters (OPEs)—chemicals commonly used as flame retardants and plastic softeners in a variety of household and industrial products—during pregnancy was associated with more behavioral issues in young children, according to a new ECHO Cohort study led by Jiwon Oh, PhD and Deborah Bennett, PhD of the University of California, Davis.

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. The study included 2,948 mother-child pairs from 12 ECHO Cohort study sites across the U.S., and the investigators used the Child Behavior Checklist for ages 1½–5 to assess each child’s behavior during early childhood.

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).

“This research builds on a growing body of evidence of potential harm caused by exposures to OPEs,” said Dr. Bennett.

Key Takeaways include:

  • Prenatal exposure to BBOEP (at moderate concentrations rather than high concentrations) was associated with more internalizing behaviors (e.g., anxiety, depression), externalizing behaviors (e.g., aggression, hyperactivity), and total behavior issues in young children.
  • Exposure to BCPP was associated with more externalizing behaviors and total behavior issues.
  • Detectable dipropyl phosphate (DPRP) was associated with 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.

“While further research is needed, our findings suggest that reducing exposure to this chemical class during pregnancy may help mitigate emotional and behavioral problems in young children,” said Dr. Oh.

This collaborative research, titled “Prenatal Exposure to Organophosphate Ester Flame Retardants and Behavioral Outcomes in Early Childhood in the Environmental influences on Child Health Outcomes (ECHO) Cohort,” is published in Environment International.

Read the research summary.

Prenatal Exposure to Phthalates, But Not Alternatives, May Influence Children’s Behavior, ECHO Study Finds

Posted on by Jodi Snare

Exposure to certain phthalates during pregnancy is associated with small to modest increases in behavioral issues, such as aggression and attention problems, in children aged 1.5 to 5 years, according to ECHO Cohort research led by Jiwon Oh, PhD and Deborah Bennett, PhD of the University of California Davis.

Researchers analyzed 27 phthalate and 6 alternative plasticizer metabolites in a large and diverse group of participants, exploring how these chemicals relate to both internalizing behaviors (like anxiety and depression) and externalizing behaviors (such as emotional reactivity, aggression, and attention difficulties).

The study found that higher levels of two specific phthalate metabolites—mono-benzyl phthalate (MBzP) and mono-hexyl phthalate (MHxP)—were connected to more externalizing behaviors, such as aggression or attention problems. However, these chemicals weren’t strongly linked to internalizing behaviors like anxiety or depression. The study also looked at a newer plasticizer called DINCH but didn’t find any effects on children’s behavior.

“While this study did not observe neurobehavioral impacts of the alternative plasticizer DINCH, a broader range of alternative plasticizers deserves attention due to their increasing use and potential neurotoxicity observed in laboratory studies,” said Jiwon Oh, PhD, of the University of California, Davis, who led the research.

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.

These findings highlight the importance of understanding how prenatal exposure to widely used chemicals may affect early childhood behavior and underscore the need for further research on plasticizers that are used as replacements for phthalates.

This collaborative research 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” is published in Environment International.

Read the research summary.

NIH Study Finds Association Between PFAS Exposures During Pregnancy and Changes in Maternal Gut Microbiome

Posted on by Jodi Snare

Exposure to per- and polyfluoroalkyl substances (PFAS)—man-made chemicals found in a variety of consumer products and contaminated water, air, and food—during pregnancy was associated with changes in maternal gut microbiome, according to a new study funded by the National Institutes of Health (NIH) Environmental influences on Child Health Outcomes (ECHO) Program.

The composition of the gut microbiome is dependent on factors including diet, lifestyle, and exposure to environmental chemicals, and has implications for human health. “Changes in the maternal microbiome may impact multiple pregnancy health outcomes related to metabolism and inflammation, thus it is important to identify environmental factors such as PFAS that can modulate microbiome form and function,” said ECHO Cohort investigator Michael Petriello, PhD of Wayne State University.

Key takeaways include:

  • Prenatal PFAS exposure was significantly associated with the relative abundance of specific types of bacteria in the maternal gut microbiome.
  • Associations between PFAS exposure and the gut microbiome differed by study location, with some bacteria present in one location but not the other.
  • In both sites, prenatal PFAS exposure did not have a significant effect on the diversity of microbes in the maternal gut microbiome.

The effect of PFAS exposure on maternal gut microbiome composition may have broader implications for the health of both the mother and baby.

“It is important to decrease exposure to pollutants such as PFAS, but complementary interventions focused on improving microbiome health and resiliency may also help to decrease the toxicity of environmental chemicals,” said Dr. Petriello.

This collaborative research, titled “Prenatal PFAS exposure and outcomes related to microbiome composition and diversity in later pregnancy,” is published in Environmental Research.

Pregnancy Diet Patterns and their Associations with Birth Outcomes Differ Across Racial and Ethnic Groups

Posted on by Jodi Snare

Dietary patterns during pregnancy can affect maternal blood sugar levels and birth outcomes, with important differences depending on racial and ethnic backgrounds, according to a recent ECHO Cohort study led by Luis E. Maldonado, PhD, MPH, of the University of Southern California.

Which combination of foods most influences blood sugar and birth outcomes during pregnancy remains unclear, especially across different racial and ethnic groups. Studying these differences is important because, although diet is known to affect birth outcomes, variations in dietary patterns may help explain disparities—for example, Hispanic women in the U.S. face higher rates of preterm birth and low birthweight compared to non-Hispanic White women.

“Our findings show it’s important to look at how diet affects birth outcomes in different racial and ethnic groups separately, especially in diverse communities,” said Dr. Maldonado. “Combining all racial and ethnic groups into one might hide important differences in how diet relates to birth outcomes for each group.”

Researchers analyzed data from over 980 pregnant women—420 Hispanic and 564 non-Hispanic White participants—from two ECHO Cohort study sites. Their aim was to identify how different combinations of food related to blood sugar and birth outcomes such as preterm birth and low birthweight.

Key takeaways

  • Diets high in refined grains (like white bread or white rice) and low in whole grains were linked to babies being born earlier, smaller, or with low birthweight.
  • Analyzing dietary patterns within specific racial and ethnic groups revealed stronger associations with negative birth outcomes than when looking at the combined group.
  • Among non-Hispanic White women, whole grains were most strongly associated with better blood sugar control.
  • Fruit was linked to higher blood sugar levels among Hispanic participants.
  • Solid fats and nuts and seeds were associated with lower blood sugar levels in both groups.

The study underscores the value of considering dietary patterns separately within racial and ethnic groups to better understand how diet affects pregnancy outcomes. Future research can build on these findings by continuing to explore culturally relevant dietary patterns in diverse populations, helping uncover associations that may be missed in broader, combined analyses.

This collaborative research, 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.