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.

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 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.

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 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

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.

Footnote: Results reported here are for a single study. Other or future studies may provide new information or different results. You should not make changes to your health without first consulting your healthcare professional.

What happens next?

Future research could help 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

Exposure to Low Levels of Arsenic in Public Drinking Water Linked to Lower Birthweight, Preterm Birth, Study Finds

Posted on June 16, 2025August 27, 2025 by Jodi Snare

Babies born to mothers potentially exposed to low levels of arsenic in public drinking water—even at levels below the federal safety standard—were more likely to be born preterm, with lower birthweight, or be smaller than expected, according to a study funded by the National Institutes of Health’s Environmental influences on Child Health Outcomes (ECHO) Program.

While the U.S. Environmental Protection Agency sets a maximum contaminant level of 10 micrograms per liter for arsenic in public water systems, this study examines how even lower-level arsenic exposures may still affect pregnancy outcomes in a large population. Previous research largely focused on private wells or smaller study groups.

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.

“Most U.S. residents rely on public drinking water, and our findings suggest that further reducing arsenic in public water systems could be an important step to improve infant health across the U.S.,” said Anne Nigra, PhD, of Columbia University’s Mailman School of Public Health. “Even low levels of arsenic in public drinking water were associated with low birthweight and other adverse birth outcomes in U.S. infants.”

Key takeaways include:

Potential arsenic exposure during pregnancy—even at levels below the current federal safety standard—may be linked to adverse birth outcomes.
Mothers exposed to higher levels of arsenic in public drinking water were more likely to have babies born with low birthweight or smaller than expected for the number of weeks of pregnancy.
These patterns were seen across several racial and ethnic groups, including White, Black, and Hispanic/Latino families. Similar risks were also observed among babies born to American Indian, Alaskan Native, Native Hawaiian, and Pacific Islander parents.
Babies born to Black parents faced higher risks of being born early, having low birthweight, or being smaller than expected.

Researchers analyzed data from nearly 14,000 mother-infant pairs from the ECHO Cohort. Arsenic exposures during pregnancy were estimated by combining water quality data with the residential histories of participants. No actual arsenic levels were tested for these participants.

This collaborative research was published in JAMA Network Open.

Nigra, A., et al. (2025) Public water arsenic and birth outcomes in the Environmental influences on Child Health Outcomes Cohort. JAMA Network Open. DOI: 10.1001/jamanetworkopen.2025.14084

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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

Check out the recent issues of our bi-monthly newsletter, the ECHO Connector, for program news and the latest research findings.

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Follow @ECHOChildHealth for the latest ECHO Program updates on X.

Prenatal Exposure to Phenols and Parabens Appear to Be Higher Among Minority Populations, ECHO Study Finds

Posted on March 7, 2025August 27, 2025 by Jodi Snare

Pregnant women in Hispanic and Black communities may experience greater prenatal exposure to endocrine-disrupting chemicals (EDCs), including environmental phenols (EPs) and parabens, according to a study funded by the Environmental influences on Child Health Outcomes (ECHO) Cohort at the National Institutes of Health (NIH).

EDCs are commonly encountered during pregnancy through everyday items such as plastics, food packaging, and personal care products. Although these products break down quickly in the body, EDCs can cross the placenta and accumulate in fetal tissue. Prenatal exposure has been linked to pregnancy complications, developmental challenges, and long-term health risks.

The findings revealed significant differences in chemical exposure levels based on race and ethnicity. Non-Hispanic Black and Hispanic participants had higher levels of certain EPs compared to non-Hispanic White participants. For example, non-Hispanic Black and Hispanic participants showed elevated levels of paradichlorobenzene—a chemical found in mothballs, fumigants, and air fresheners. Non-Hispanic Black participants also had higher levels of parabens, commonly used as preservatives in processed foods and personal care items.

“These findings indicate that pregnant individuals from different racial and ethnic backgrounds experience varying levels of exposure to potentially harmful chemicals,” said Michael S. Bloom, PhD, of George Mason University. “Understanding these differences is crucial for evaluating their effects on maternal and fetal health and identifying the underlying causes can inform effective interventions.”

Researchers analyzed urine samples from 4,006 pregnant participants across 11 ECHO Cohort Study Sites, representing Hispanic, non-Hispanic Black, non-Hispanic Other, and non-Hispanic White individuals.

Low-income and minority communities may face heightened exposure due to factors like proximity to industrial facilities and limited access to a broad range of consumer products and fresh foods, researchers noted in the study.

This collaborative research was published in the Journal of Exposure Science and Environmental Epidemiology.

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Bloom, M.S., Upadhyaya, S., Nzegwu, A.W. et al. Racial and ethnic differences in prenatal exposure to environmental phenols and parabens in the ECHO Cohort. J Expo Sci Environ Epidemiol (2025). https://doi.org/10.1038/s41370-025-00750-w

Media Contacts

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

If you are not a member of the media, but have a general inquiry, please contact NIHKidsandEnvironment@od.nih.gov.

Connect With Us

Check out the recent issues of our bi-monthly newsletter, the ECHO Connector, for program news and the latest research findings.

To receive the ECHO Connector through email, subscribe here.

Follow @ECHOChildHealth for the latest ECHO Program updates on X.

Prenatal Exposure to Phenols and Parabens Higher Among Minority Populations, ECHO Study Finds

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Prenatal Exposure to Phenols and Parabens Higher Among Minority Populations, ECHO Study Finds

Authors: Michael S. Bloom, Adaeze Wosu Nzegwu, et al.

Who sponsored this study?

The Environmental influences on Child Health Outcomes (ECHO) Program, National Institutes of Health supported this research.

Why was this study needed?

Exposure to endocrine-disrupting chemicals (EDCs), such as environmental phenols (EPs) and parabens, is common during pregnancy through everyday products like plastics, food packaging, and personal care items. These chemicals can cross the placenta and, despite their short breakdown time in the body, EPs are often detected in human tissue. Prenatal exposure has been linked to risks such as pregnancy complications, developmental issues, and long-term health problems, particularly in underserved populations. Low-income and minority communities may face higher exposure to chemicals like EPs due to closer proximity to factories and waste facilities, as well as limited access to a broader range of consumer products and fresh foods. This study investigated racial and ethnic differences in prenatal exposure to EPs and parabens across the U.S., addressing the limitations of earlier, smaller studies that did not fully explore these differences among pregnant women.

What were the study results?

Urinary levels of most EPs examined varied significantly by race and ethnicity, with non-Hispanic Black and Hispanic participants having higher levels of certain EPs than non-Hispanic White participants. Specifically, non-Hispanic Black and Hispanic participants had higher average levels of a chemical that comes from paradichlorobenzene in their urine compared to non-Hispanic White participants. Paradichlorobenzene is found in mothballs, fumigants, and air fresheners, and it is mainly inhaled. Non-Hispanic Black participants also had higher levels of specific parabens, which are preservatives used in processed foods and personal care products. These chemicals can be absorbed through eating or using such products.

What was this study's impact?

The study highlighted the disproportionately high levels of exposure to EPs among pregnant racial and ethnic minorities in the U.S.

Who was involved?

The study included 4,006 pregnant participants from 11 ECHO Cohort Study Sites across the U.S., representing various racial/ethnic identities, including Hispanic, non-Hispanic Black, non-Hispanic Other, and non-Hispanic White individuals.

What happened during the study?

The study analyzed 7,854 urine specimens collected during pregnancy. Researchers measured the levels of 10 different urinary EPs.

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?

Further studies could examine the sources of these exposure differences.

Where can I learn more?

Access the full journal article, titled “Racial and ethnic differences in prenatal exposure to environmental phenols and parabens in the ECHO Cohort,” in the Journal of Exposure Science and 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 February 15, 2025

Access the associated press release.

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Prenatal Exposure to Phenols and Parabens Higher Among Minority Populations, ECHO Study Finds

Researchers Publish Overview of Existing Chemical Exposure Research using ECHO Cohort Data

Posted on September 24, 2024April 1, 2025 by Jodi Snare

ECHO Research Spotlight — September 2024

ECHO researchers led by Emily Barrett, PhD, MA of the Rutgers University School of Public Health published a scoping review of existing ECHO research that evaluates the impact of chemical exposures on maternal and child health. A scoping review summarizes and provides an overview of the past and current research on a topic at a given point in time.

The review, titled “Advancing Understanding of Chemical Exposures and Maternal-child Health Through the U.S. Environmental influences on Child Health Outcomes (ECHO) Program: A Scoping Review,” was recently published in Current Environmental Health Reports.

While specific environmental chemical exposures have been proven to impact child well-being, exposure studies are often limited in size and variance, limiting the ability to draw generalizable conclusions from results. With data from more than 60,000 participants from 69 groups of pregnant participants, the ECHO program is the largest study of U.S. children’s health and a unique opportunity for more-representative research.

Barrett and her team analyzed the current landscape of chemical exposure research using ECHO Cohort data. The review was developed to understand how the program has made strides in understanding environmental contributors to maternal and child health.

“With several years of ECHO under our belts, including thousands of biospecimens analyzed for chemical exposures (by ECHO researchers), we thought it was time to check in on the progress that had been made and to highlight the new opportunities opening in Cycle 2 of ECHO,” she said.

Through December 31, 2023, 1,530 papers total were published acknowledging ECHO funding. As of early 2024, there were more than 200 single-cohort papers published on chemical exposures through support of ECHO. In addition, 10 collaborative multi-cohort papers have been published using harmonized ECHO Cohort data. These multi-cohort papers have examined prenatal exposure to per- and polyfluoroalkyl substances (PFAS), phthalates, phenols, parabens, organophosphate esters (OPEs), metals, melamine, aromatic amines, and emerging contaminants.

The NICHD’s Data and Specimen Hub (DASH) database houses extensive ECHO data including over 470,000 chemical assay results and complementary data on priority outcome areas (pre, peri-, and postnatal, airway, obesity, neurodevelopment, and positive health), making it a rich resource for future analyses.

The review points out that ECHO research has focused primarily on prenatal exposures as they relate to birth outcomes such as preterm birth or size at birth. Studies focused on later child health outcomes are anticipated in coming years as follow-up of participating children continues.

“As the ECHO Cohort matures, we’ll be better able to address later child health outcomes including asthma, neurodevelopmental disorders, and obesity,” Barrett said. “With many more ECHO-wide analyses of chemical exposures data ongoing, this is a really active area within ECHO. I would love to update this review five years from now, so we can see just how far we’ve come.”

Barrett also emphasized the value of ECHO research into new and emerging contaminants that may pose risks for children. “As older chemicals are phased out, often due to safety concerns, and newer replacements emerge, it’s imperative that we understand how they may be impacting children’s health and development,” she said.

New ECHO Research Investigates Relationship Between Phthalate Exposure and High Blood Pressure, Related Complications During Pregnancy

Posted on June 5, 2024July 2, 2024 by Jodi Snare

Collaborative ECHO research led by John Meeker, ScD of the University of Michigan, and Jordan Kuiper, PhD of George Washington University, investigates the relationship between phthalate exposure and high blood pressure during pregnancy. This research, titled “Urinary concentrations of phthalate metabolites in relation to preeclampsia and other hypertensive disorders of pregnancy in the Environmental influences on Child Health Outcomes (ECHO) program,” is published in Environment International.

This study aimed to evaluate whether phthalate exposures could be linked to ongoing high blood pressure during pregnancy and more severe pregnancy complications like preeclampsia or eclampsia.

“The findings of this study suggest that exposure to certain phthalates found in plastics and other consumer products may be associated with pregnancy complications such as gestational hypertension or preeclampsia,” said Meeker.

Researchers evaluated data from 3,430 participants from eight ECHO sites across the U.S., which enrolled pregnant participants from 1999 to 2019. In the study, researchers measured the levels of 13 metabolites linked to phthalate exposure in urine samples collected at least once during pregnancy. They then evaluated the association between individual phthalates, as well as the combined mixture of phthalates, with the risk of developing preeclampsia, eclampsia, or ongoing high blood pressure during pregnancy.

The researchers measured phthalate exposure by checking urine levels of certain small molecules, called metabolites, that the body makes when it breaks down chemicals. They found that higher levels of these metabolites were linked to a higher risk of pregnancy complications like preeclampsia, eclampsia, and ongoing high blood pressure. For example, if the level of a metabolite called mono (3-carboxypropyl) phthalate (MCPP) doubled, the risk of developing preeclampsia or eclampsia increased by 12%. MCPP is related to phthalates found in PVC plastics and insect repellents.

The researchers also examined combined phthalate exposure by dividing participants into four groups based on their exposure levels. Each increase in exposure level was linked to a 27% higher risk of preeclampsia or eclampsia, which was generally higher for pregnant women carrying female fetuses.

Future studies can help researchers understand how exposure to phthalates might be linked to high blood pressure during pregnancy, how this happens in the body, and what we can do to reduce the risk of these pregnancy complications.

Read the research summary.

ECHO Researchers Investigate Association of Early Childhood Phthalate Exposures with ADHD Behaviors in Childhood and Adolescence

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ECHO Researchers Investigate Association of Early Childhood Phthalate Exposures with ADHD Behaviors in Childhood and Adolescence

Authors: Jiwon Oh, Julie B. Schweitzer, 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?

Phthalates are widely used chemicals found in many everyday items such as food packaging, flooring, building materials, medicine coatings, medical supplies, cosmetics, and personal care products. When phthalates enter the body, they are metabolized and converted into various smaller molecules, known as metabolites.

Animal studies suggest that exposure to phthalates during early life may negatively affect the nervous system, but there has been limited investigation into potential associations between early childhood phthalate exposure and attention-deficit/hyperactivity disorder (ADHD) behaviors in later childhood and adolescence.

For this study, ECHO researchers wanted to investigate whether exposure to phthalates in children at ages 2-5 years was associated with ADHD symptoms when these children were ages 8-18 years.

Learn how to say phthalate.

What were the study results?

ECHO Cohort researchers evaluated the levels of several metabolites that result from phthalate exposure. They saw that in children ages 2-5 years, most of these molecules were not associated with ADHD behaviors in these children at ages 8-18 years.

However, among children who had been diagnosed with autism spectrum disorder (ASD), one of these metabolites—mono-2-heptyl phthalate (MHPP)—was associated with more ADHD behaviors. Among typically developing children, a different small molecule—mono-carboxy isooctyl phthalate (MCiOP)—was associated with more hyperactive/impulsive behaviors.

What was this study's impact?

This study suggests that early childhood exposure to certain phthalates may be associated with having both ASD and ADHD traits. Since ADHD behaviors are more commonly found in children with ASD, deepening the understanding of how exposure to environmental chemicals, such as phthalates, could contribute to this comorbidity may be important for managing and treating these conditions effectively.

Note: The results reported here are from a single study. Other or future studies may provide new information or different results. You should consult with a qualified healthcare provider for diagnosis and for answers to your personal questions.

Who was involved?

This study included 243 children living in Northern California and taking part in the ReCHARGE (Revisiting Childhood Autism Risks from Genetics and Environment) study. This study included both neurotypical and neurodiverse children, with about 60% of them having ever had neurodevelopmental concerns. Therefore, the children included in the study tended to have more ADHD behaviors compared with children in the general population.

What happened during the study?

Phthalate metabolites can be measured in biological samples, such as urine, to assess exposure to phthalates. In this study, the researchers measured 15 phthalate metabolites in urine samples of young children ages 2-5 years. Parents answered questions about each child’s ADHD symptoms at ages 8-18 years.

What happens next?

While the metabolite MHPP and the phthalate it’s derived from, di-n-heptyl phthalate (DHPP), are commonly found in children’s urine, their influence on neurodevelopment has not been studied as much as other phthalates. Since exposure to DHPP has been linked to problems with development and behavior in animals, further studies need to look more closely at this compound to understand its effects on how the brain develops in children.

Where can I learn more?

Read the full research article, titled “Early childhood exposures to phthalates in association with attention-deficit/hyperactivity disorder behaviors in middle childhood and adolescence in the ReCHARGE study,” in the journal International Journal of Hygiene and Environmental Health.

Learn more about ECHO’s other chemical exposure research.

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

Published June 2024

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ECHO Researchers Investigate Association of Early Childhood Phthalate Exposures with ADHD Behaviors in Childhood and Adolescence

ECHO Researchers Examine the Effect of Perinatal Synthetic Oxytocin Exposure and Maternal BMI on Child Neurodevelopmental Outcomes

Posted on May 28, 2024May 29, 2024 by Jodi Snare

Collaborative ECHO Cohort research led by Lisa Kurth, PhD of the University of Colorado, Anschutz Medical Campus investigates the potential influence of maternal exposure to synthetic oxytocin during childbirth—and the contribution of maternal obesity—on neurodevelopmental outcomes in children. Synthetic oxytocin (e.g., Pitocin, Syntocinon) is a drug commonly used to assist women during childbirth by stimulating uterine contractions.

The researchers examined data from over 12,000 mother-child pairs to look at possible associations between maternal exposure to synthetic oxytocin, maternal pre-pregnancy body mass index (BMI), and childhood ADHD and Autism Spectrum Disorder (ASD). The results of this study found no significant correlation between synthetic oxytocin exposure and the risk of ADHD and ASD in children. However, an unexpected finding in this study was that synthetic oxytocin exposure was associated with a decreased childhood risk of ADHD in children born to mothers with pre-pregnancy obesity. Additionally, mothers with pre-pregnancy obesity demonstrated a modest trend toward labor intervention with synthetic oxytocin. This research, titled “Intrapartum Exposure to Synthetic Oxytocin, Maternal BMI and Neurodevelopmental Outcomes in Children within the ECHO Consortium,” is published in the Journal of Neurodevelopmental Disorders.

Previous studies on the association between synthetic oxytocin and children’s risk of ADHD and ASD have been decidedly mixed, and the potential impact of the mother’s pre-pregnancy BMI on this association has, until now, not yet been examined. This study analyzed data from participating mothers, 48% of whom were exposed to synthetic oxytocin during childbirth, and their children from ECHO Cohort research sites across the U.S.

Although no significant correlation was found between synthetic oxytocin-assisted childbirth and neurodevelopmental outcomes in children, future research may further unravel the effects of childbirth factors such as synthetic oxytocin dosage, maternal labor duration, maternal gestational obesity and Caesarean delivery rationale, indicators of newborn health (e.g., initial Apgar score, meconium stain, newborn birthweight), and maternal BMI at time of delivery on infant well-being in relationship to child neurodevelopmental outcomes. Important next steps include analysis of biospecimens (placental tissue and cord blood) aimed at understanding the specific mechanism(s) of action involved in synthetic oxytocin exposure.

“Casting a wider net and including additional factors will allow future studies to more precisely examine the effects of important perinatal factors, including environmental exposures, and effect modifiers, such as maternal obesity, on child neurodevelopmental outcomes,” said Dr. Kurth.

Read the research summary.