News

Pregnancy Stress Can Influence Relationship Between Chemical Exposures & Birth Outcomes, ECHO Study Finds

Posted on by Jodi Snare

Stress, anxiety, and depression during pregnancy and maternal adverse childhood experiences may influence the relationship between certain chemical exposures and birth outcomes, according to a new ECHO Cohort study led by Stephanie Eick, PhD, MPH and Anne Dunlop, MD, MPH of Emory University.

Most previous research on the effects of chemical exposures on birth outcomes has focused on a small number of well-established chemicals, such as bisphenol A (BPA) and certain phthalates. However, there are over 350,000 chemicals registered for global use, and the impact of many emerging or understudied chemicals on birth outcomes is not well understood. Additionally, prior studies have not adequately considered how different kinds of maternal stress (such as anxiety, depression, and adverse childhood experiences) might influence the effects of chemical exposures during pregnancy.

This study included 1,556 mother-child pairs from eleven ECHO Cohort Study Sites across the United States. Researchers analyzed urine samples from pregnant participants for 113 different chemicals from 10 chemical classes. Participants also reported on their stress, depression, anxiety, and adverse childhood experiences, allowing researchers to evaluate how these factors affect the relationship between different chemical exposures and birth outcomes.

Key Takeaways include:

  • Exposure to chemicals found in certain consumer and industrial products (such as phthalates, bisphenols, and insecticides) was associated with shorter pregnancies among women who experienced anxiety during pregnancy or in the early postpartum period.
  • Depression modified how exposure to certain chemicals (such as phthalates, parabens, and insecticides) affected birthweight and length of pregnancy.
  • Some chemicals positively correlated with length of pregnancy (duration) for mothers with more depression, while others were associated with lower birthweights when mothers had more depression symptoms.
  • The effects of a mother’s stress on the relationship between chemical exposures and birth outcomes depended on the type of chemical and type of stressor experienced.

“These findings suggest that screening for depression and anxiety during pregnancy could help identify women who may be at a higher risk of adverse birth outcomes,” said Dr. Eick.

Additional studies looking at the combined effects of multiple combined exposures could help researchers better understand the role of these factors in influencing birth outcomes. Future research could also further investigate potential biological effects of maternal adverse childhood experiences.

This collaborative research, titled “Psychosocial Stressors as Modifiers of the Associations Between Well-Studied and Understudied Chemicals and Birth Outcomes in the ECHO Cohort,” is published in Environmental Pollution.

Read the research summary.

Community Gun Violence Linked to Poorer Child Health, ECHO Study Finds

Posted on by Jodi Snare

Children living in neighborhoods with high levels of gun violence were 20% less likely to be reported in excellent or very good health compared with children in areas with lower levels of gun violence, according to a new study from the ECHO Cohort. The association was consistent across age groups and especially pronounced in high-poverty neighborhoods, where children exposed to gun violence were 23% less likely to be reported in excellent health.

The study included more than 13,450 children from birth to age 17 from 56 ECHO Cohort Study Sites across the United States. Researchers linked data on neighborhood gun violence, collected from the Gun Violence Archive, with parent-reported child health measures, while accounting for individual and neighborhood sociodemographic factors.

“This research highlights the profound impact of gun violence on the well-being of children, underscoring the critical importance of community-level violence prevention efforts and policies in fostering safer and healthier communities,” said study author Nandita Somayaji, MHS, MEd, of the Bloomberg School of Public Health at Johns Hopkins University.

These findings point to the importance of gun violence prevention strategies that can create safer environments for children.

This collaborative research titled “Associations between neighborhood-level gun violence and child general health status: An ECHO Cohort analysis” was published in Injury.

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 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.

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.

Exposure to Phenols During Pregnancy Associated with Changes in Non-nutritive Suck Patterns in Infants, an Early Indicator of Brain Development

Posted on by Jodi Snare

Exposure to phenols—chemicals used in a variety of consumer products and industrial processes that can disrupt hormones—during pregnancy was associated with changes in patterns of infant non-nutritive suck, according to ECHO Cohort research led by Megan Woodbury, PhD and Emily Zimmerman, PhD, CCC-SLP of Northeastern University, and Andréa Aguiar, PhD of University of Illinois Urbana-Champaign.

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.

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.

Key takeaways include:

  • Exposure to Bisphenol F, a common alternative to Bisphenol A or BPA found in some food packaging, was related to a lower non-nutritive suck frequency.
  • 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) was 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.

Previous studies linking changes in non-nutritive suck patterns to other exposures, such as maternal pregnancy stress and prenatal phthalate exposures, have also linked these exposures with decreased cognitive function in infants. The reasons these associations occur in the body are unknown but may be linked to hormone disruption during pregnancy.

“This study provides additional evidence that exposure to phenols may be related to developmental outcomes in children, demonstrating the need for continued research into how exposures during pregnancy impact infant health and development,” said Dr. Woodbury.

This collaborative research, titled “Examining the association between prenatal Phenol exposure and infant non-nutritive suck in two ECHO Cohorts,” was published in Environmental Epidemiology.

Study Links Higher Air Pollution to Increased Childhood Asthma, Highlights Unequal Burden in Black and Urban Communities

Posted on by Jodi Snare

Higher exposure to fine particulate matter, nitrogen dioxide, and ground-level ozone was associated with increased asthma incidence in children up to age 10, according to a new study funded by the Environmental influences on Child Health Outcomes (ECHO) Program at the National Institutes of Health. Notably, children living in areas with higher proportions of Black residents or higher population density faced greater pollution-related asthma risk, despite overall air quality improvements in the U.S.

“Our findings show why it’s so important to keep reducing air pollution everywhere in the U.S. They also highlight the need to understand and tackle the deeper reasons why some communities are more affected than others,” said Veronica Wang, research fellow at the Harvard T.H. Chan School of Public Health.

Key Takeaways:

  • Higher levels of fine particulate matter, nitrogen dioxide, and ground ozone were each linked to more new cases of asthma in early childhood.
  • Fine particulate matter and nitrogen dioxide posed a greater asthma risk for children living in areas with more Black residents.
  • Children in more densely populated neighborhoods were also at higher risk from these pollutants.
  • The study looked at data from over 23,000 children born between 1981 and 2021 to find out which groups are more likely to develop asthma from air pollution exposure in early childhood.

The study analyzed extensive environmental and community data, highlighting the importance of reducing harmful exposures in the most affected neighborhoods.

This collaborative research was published in Environmental Epidemiology.