ECHO Study Suggests Antimony Exposure During Pregnancy Contributes to Lower Birth Weight

Authors: Caitlin Howe, Margaret R. Karagas, et al.

Who sponsored this study?

This research was supported by the Environmental influences on Child Health Outcomes (ECHO) program, Office of The Director, National Institutes of Health.

What were the study results?

Researchers found that combined exposure to all metals in the mixture did not affect birth weight. Mothers with high levels of the metal antimony in their urine had smaller babies across all three of the ECHO cohorts. Two other metals – cadmium and molybdenum – had no impact on fetal growth. Findings for other metals (cobalt, mercury, nickel, tin) varied depending on the study population and whether the baby was male or female.

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 was the study's impact?

This study used an approach that looked at multiple chemicals at once, in contrast to previous studies that have typically evaluated one chemical at a time. The findings suggest that antimony, an understudied metalloid, may harm fetal growth in different populations across the United States.

Why was this study needed?

Exposure to toxic metals can harm fetal growth (how much a baby grows during pregnancy), while nutritionally essential metals can support fetal growth. Previous research studying the effects of metals during pregnancy on fetal growth has usually focused on one metal at a time. However, most people are exposed to multiple metals, which may have complex effects on fetal growth. Therefore, combining data from three ECHO cohorts representing different geographic regions in the U.S., the research team looked at how maternal exposure to multiple metals affects fetal growth, an important indicator of future health.

Who was involved?

This study included approximately 1,000 pairs of mothers and newborns who are participating in three ECHO cohorts:

The MADRES study, a predominantly lower income Hispanic cohort in Los Angeles, California
The NHBCS, a primarily non-Hispanic white cohort in northern New England
The PROTECT study, a Hispanic cohort in northern Puerto Rico.

What happened during the study?

The research team combined data from the three cohorts to measure multiple metals in the mothers’ urine samples collected during pregnancy. They then looked at associations between seven metals and birth weight for gestational age using a multi-chemical mixture approach. Birth weight for gestational age is commonly used as a measure for fetal growth.

What happens next?

Since antimony may harm fetal growth, it is important to identify major sources of exposure to this metal so that exposure can be reduced for pregnant women. In future studies, the team would like to include more ECHO cohorts in their research, explore other indicators of metal exposures (such as placental measures of metals), and identify time periods when toxic and essential metal exposures are most harmful or beneficial for pregnant women and their children.

Where can I learn more?

The full journal article, titled “Prenatal metal(loid) mixtures and birth weight for gestational age: a pooled analysis of three cohorts participating in the ECHO Program” is published 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 March 01, 2022

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ECHO Study Suggests Antimony Exposure During Pregnancy Contributes to Lower Birth Weight

ECHO Study Suggests Link Between Smoking During Pregnancy and Autism-Related Traits in Children

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ECHO Study Suggests Link Between Smoking During Pregnancy and Autism-Related Traits in Children

Authors: Rashelle J. Musci, Irva Hertz-Picciotto, et al.

Who sponsored this study?

This research was supported by the Environmental influences on Child Health Outcomes (ECHO) program, Office of The Director, National Institutes of Health.

What were the study results?

Smoking before or during pregnancy was consistently associated with ASD traits, such as symptoms of social impairments. Additionally, babies born at full term had a somewhat higher risk of receiving an ASD diagnosis as a child if their mothers smoked before or during the pregnancy.

More counseling is needed for pregnant women or those planning a pregnancy to help them understand how these potential risks for the child’s behavioral development add to other poor outcomes associated with smoking during pregnancy, such as low birthweight, increased likelihood of fetal or infant death, asthma in early childhood, or attention deficit hyperactivity disorder (ADHD).

Footnote: Results reported here represent results from 11 or seven studies, depending on the outcome. Other or future studies may provide new information or different results. Consult your healthcare professional for guidance on how to limit your unborn child’s exposure to tobacco smoke. However, please also note that you have a greater chance of improving your child’s health and their social and behavioral development the sooner you quit or reduce smoking.

What was the study's impact?

There are many reasons for women to limit their exposure to tobacco smoke during pregnancy—tobacco smoke increases risk for low birthweight, ectopic pregnancy, a premature delivery, or fetal/infant death. Less research has been done to learn how tobacco smoke can influence children’s health, although studies have linked prenatal smoking to higher childhood asthma and ADHD risk. This study shows how prenatal exposure to cigarette smoke may also harm a child’s social development. Social skills can be important for success in school and getting along with others. Doctors, child educators, and other health and daycare providers should also know that children exposed to prenatal cigarette smoke may also be at higher risk for developing ASD.

Why was this study needed?

Previous studies provide varying results on how tobacco smoke exposure during pregnancy may affect risk for autism spectrum disorder (ASD) in children. Exposures to air pollution, which has many of the same chemicals as tobacco smoke but at lower levels, have also been linked with ASD. ASD is a complex condition that involves not only trouble in social interactions but also communication problems and patterns of repetitive behaviors or narrow interests.

The research team set out to conduct a study with participants from across the U.S. that could clear up inconsistencies found in previous research. Additionally, no other research has looked at the relationship between maternal tobacco smoking and milder autism-like symptoms of social impairment.

Who was involved?

Researchers studied approximately 11,000 children in 13 cohorts around the U.S. who either had a diagnosis of ASD, social impairment measurable on the Social Responsive Scale, or both. There also had to be information on exposure to prenatal smoking and other factors that could influence the study results.

What happened during the study?

Researchers pulled together and analyzed results from each cohort related to maternal smoking behaviors before or during pregnancy and childhood ASD diagnosis or ASD-related social impairment. The team took specific actions to prevent other factors related to the children and mothers from affecting the quality and consistency of the data.

What happens next?

Future studies can help researchers identify when babies are most at-risk to cigarette smoke exposure and how other factors associated with prenatal smoking may contribute to negative health outcomes.

Where can I learn more?

Access the full journal article, titled “Maternal Tobacco Smoking and Offspring Autism Spectrum Disorder or Traits in ECHO Cohorts” in Autism Research.

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

Published February 24, 2022

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ECHO Study Suggests Link Between Smoking During Pregnancy and Autism-Related Traits in Children

ECHO Study Links Prenatal Tobacco Exposure to Autism Spectrum Disorder in Children

Posted on February 24, 2022December 5, 2023 by Jodi Snare

Through a collaborative research effort, Rashelle J. Musci, PhD of Johns Hopkins University and Irva Hertz-Picciotto, PhD of the University of California, Davis found that maternal tobacco use before or during pregnancy was associated with autism spectrum disorder (ASD) traits, such as symptoms of social impairment. Examples of social, communication, or other behaviors among individuals with ASD include little or no eye contact, difficulty with engaging in conversation, insistence on doing things the exact same way, repetitively, or having a narrow set of interests. Additionally, the researchers found that full-term babies whose mothers smoked before or during pregnancy had a 44% increased risk of receiving an ASD diagnosis later in childhood. Their research, titled “Maternal Tobacco Smoking and Offspring Autism Spectrum Disorder or Traits in ECHO Cohorts” is published in Autism Research.

“Previous studies provide varying results on how tobacco smoke exposure during pregnancy affects a child’s risk for autism,” said Dr. Hertz-Picciotto, highlighting the importance of this research.

To collect data, the research team gathered information from approximately 11,000 children in 13 cohorts across the United States. Each of the cohorts either collected diagnoses for ASD or administered the Social Responsiveness Scale to determine social impairments in the children, or both. The research team studied each cohort individually and combined these findings to come up with an overall result. It also collected data on the mothers’ prenatal smoking habits and other potential confounding variables.

“This study adds to existing evidence that suggests that by ceasing smoking before or during pregnancy, the mother benefits her child,” noted lead author Dr. Musci.

Future studies can help determine the specific prenatal period at which infants are most susceptible to cigarette smoke exposure and other factors, such as lifestyle habits or paternal smoking, that may influence the child’s development.

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ECHO Researchers Develop a Shorter Survey for Evaluating Sources of Stress in Adults

Posted on February 21, 2022December 8, 2023 by Jodi Snare

Through a collaborative effort led by Phillip Sherlock, PhD from Northwestern University, an ECHO research team developed a short-form version of the Crisis in Family Systems-Revised (CRISYS-R) questionnaire for evaluating the sources of stress that adults experience. The study found that the revised 24-question survey (CRISYS-SF) covered the same 11 areas of stress the 80-question CRISYS-R addressed and yielded very similar scores. The article, titled “A short form of the Crisis in Family Systems (CRISYS) in a racially diverse sample of pregnant women,” is published in Current Psychology.

The researchers interviewed 884 pregnant women in the PRogramming of Intergenerational Stress Mechanisms (PRISM) study from New York City and Boston. About 20% of these women spoke Spanish as their primary language, 20% had less than a high school education, and 60% reported having some degree of financial trouble. The participants answered all 80 of the CRISYS-R questions, and the researchers used statistical methods and expert input to identify which questions were the most useful for measuring stress.

Growing evidence suggests that exposure to stress can affect a patient’s overall health. The CRISYS-SF is a convenient method for doctors and researchers to more easily screen for participant stress, identify the sources of that stress, and plan effective interventions.

“Factors including questionnaire length contribute to participant burden,” said Dr. Sherlock, “and this burden can contribute to reduced response rate, incomplete data, and reduced data quality in clinical studies.” Future research into the effects of stress on specific health outcomes will benefit from the use of the CRISYS-SF questionnaire to gather reliable, high quality data on participant stress.

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ECHO Study Links Fast Growth During First Five Years of Life With Younger Onset of Puberty in Children

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ECHO Study Links Fast Growth During First Five Years of Life With Younger Onset of Puberty in Children

Author: Izzuddin M. Aris, et al.

Who sponsored this study?

This research was supported by the Environmental influences on Child Health Outcomes (ECHO) program, the Office of the Director, and the National Institutes of Health.

What were the study results?

In male children, gaining weight or growing faster than their peers in the first five years of life was associated with entering puberty at a younger age. The researchers found similar results in female children, but only among those with faster weight gains during early childhood (two to five years of age). Female children with faster weight gains during infancy (six months to two years of age) and early childhood started their periods earlier and had more advanced pubic hair development.

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 was the study's impact?

This study has a direct clinical impact. As pediatricians regularly measure weight and height during routine visits and use growth curves to identify abnormal growth predictions, they could closely monitor children who have faster weight and height gains in the first five years of life for earlier onset of puberty. These study results may also inform future studies that aim to develop and/or test interventions to potentially help prevent earlier onset of puberty, such as good nutrition, environmental exposures, physical activity, and other behaviors related to growth during the first five years of life.

Why was this study needed?

Puberty is a key stage during child development. Previous research indicates that children in the United States are entering puberty at younger ages. These children may be in danger of developing certain diseases, such as type 2 diabetes, later in life. A better understanding of how early life factors affect puberty development is important for combating earlier puberty onset.

Who was involved?

This study included almost 7,500 children from 36 birth cohorts. All participating cohorts had documented at least one measure of weight and height in the first five years of the child’s life and at least one measure of puberty development.

What happened during the study?

The researchers used participants’ weight and height data to look at the following signs of puberty: age when the child experienced the most growth due to puberty; age of their first period (in female children only); puberty development score; and pubic hair development. The team then examined how gains in weight, height, and body mass index at different stages between birth and age 5 were related to puberty development, controlling for maternal and child characteristics.

What happens next?

The team planned follow-up studies that will aim to identify the mechanisms behind these initial observations. They also aim to identify the role of puberty in explaining the relationship between early life factors and longer-term chronic diseases, such as type 2 diabetes.

Where can I learn more?

Access the full journal article, titled “Analysis of early life growth and age at pubertal onset in US children” 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 February 4, 2022

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ECHO Study Links Fast Growth During First Five Years of Life With Younger Onset of Puberty in Children

ECHO Researchers Explore How Maternal Stress During Pregnancy Relates to Infant Suck Patterns

Posted on January 3, 2022December 8, 2023 by Jodi Snare

Collaborative ECHO research led by Emily Zimmerman, PhD, CCC-SLP from Northeastern University and Andréa Aguiar, PhD from the University of Illinois at Urbana-Champaign found that a mother’ s level of stress during pregnancy was linked to changes in the way her infant sucked on a pacifier.

Infants’ sucking patterns can be used to measure brain function soon after birth, and this research investigated how maternal stress during pregnancy related to infant suck patterns. Zimmerman, Aguiar, and team found that mothers who felt more stressed late in their pregnancy had infants who sucked on their pacifiers less frequently, but when they did suck on their pacifier, they did so for a longer period of time compared with infants of mothers who felt less stressed in late pregnancy. It is important to note that the mother and infants participating in this study were from two different groups who had different maternal stress levels and infants’ sucking behaviors. These differences in stress and infants’ sucking behaviors could be due to other differences between the two groups in their culture, ethnicity, geographical location, and income, and education levels.

This research, titled “Examining the Association Between Prenatal Maternal Stress and Infant Non-Nutritive Suck,” was published in Pediatric Research.

To collect data, the researchers surveyed mothers from two ECHO cohorts—one from Urbana-Champaign, Illinois and the other from Manati, Puerto Rico—regarding their stress during late pregnancy using the Perceived Stress Scale. The researchers followed up with each mother within 8 weeks after giving birth and tested their baby’s sucking pattern on a pacifier connected to a pressure detector.

This research demonstrates that maternal mood and stress during pregnancy can affect infant behavior and development starting prenatally and through the first months of life. “This finding is important as it may allow for earlier awareness of stress exposure during pregnancy,” said Dr. Zimmerman, “and as a result, earlier treatment for stress-exposed infants.”

The next steps for this research include further investigation of the link between early infant sucking patterns and visual memory, attention, and speed processing in infants.

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ECHO Study Suggests Link Between Maternal Stress During Late Pregnancy and Infant Pacifier Sucking Patterns

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ECHO Study Suggests Link Between Maternal Stress During Late Pregnancy and Infant Pacifier Sucking Patterns

Author(s): Emily Zimmerman, Andréa Aguiar, et al.

Who sponsored this study?

This research was supported by the Environmental influences on Child Health Outcomes (ECHO) program, the Office of the Director, and the National Institutes of Health.

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

What were the study results?

The researchers found that higher maternal stress during late pregnancy was associated with fewer but longer sucking bursts when the infants sucked on the special pacifier. It is important to note that the maternal stress levels and infants’ sucking behaviors between the two cohorts were different. This could be due to differences between the two cohorts’ cultures, geographical locations, ethnicities, incomes, and education levels.

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 was the study's impact?

This is the first study investigating the link between maternal stress and infants’ sucking patterns. The results of this study may help promote awareness and earlier detection of stress exposure during pregnancy and, as a result, improve the treatment of stress-exposed infants. This study also researched these outcomes in two groups of participants with different demographics and stress levels, which may allow for earlier detection of high maternal stress exposure in lower SES populations.

Why was this study needed?

Previous studies show that a mother’s stress during pregnancy can affect her baby’s development. But less is known about how a mother’s stress during pregnancy relates to their infant’s brain function early in life. Infants’ sucking patterns have been used to measure brain function soon after birth. This study investigated whether there was any relationship between mothers’ stress in pregnancy and their young infants’ sucking patterns.

Who was involved?

The study included participants from two ECHO cohorts—one from Urbana-Champaign, Illinois and the other from Manati, Puerto Rico.

What happened during the study?

The researchers surveyed mothers regarding their stress during late pregnancy using the Perceived Stress Scale, which has 10 questions. Next, between one and eight weeks after the mothers gave birth, the researchers measured the infants’ sucking behaviors by having them suck on a pacifier connected to a pressure detector for approximately five minutes.

What happens next?

Future studies will look at the question of how early sucking behaviors relate to a child’s growth and development, in particular their brain function and cognitive development.

Where can I learn more?

Access the full journal article, titled “Examining the Association Between Prenatal Maternal Stress and Infant Non-Nutritive Suck” in Pediatric Research.

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

Published December 16, 2021

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ECHO Study Suggests Link Between Maternal Stress During Late Pregnancy and Infant Pacifier Sucking Patterns

How Does Maternal PFAS Exposure Affect Prenatal Development?

Posted on November 18, 2021December 8, 2023 by Jodi Snare

Per- and polyfluoroalkyl substances (PFAS) are long-lasting chemicals that can be found in many household materials, but not enough is known about pre- and perinatal negative health outcomes associated with PFAS exposure. Additionally, socioeconomically disadvantaged groups, such as African American women and children, may be at more risk for PFAS exposure, worsening health disparities. Previous studies have linked PFAS exposure with negative infant health outcomes, such as lower birth weight, but little is known about the specific biological mechanisms that PFAS exposures disrupt during prenatal development.

Che-Jung Chang, PhD (left) and Donghai Liang, PhD (right) served as first and corresponding authors for this publication.

To investigate these mechanisms, Che-Jung Chang, PhD, Donghai Liang, PhD, and their team of ECHO researchers at Emory University looked at pregnancy and exposure data from more than 300 African American women enrolled in the Atlanta ECHO cohort from 2014-2018. Their research, titled “Per- and polyfluoroalkyl substance (PFAS) exposure, maternal metabolomic perturbation, and fetal growth in African American women: A meet-in-the-middle approach,” is published in Environment International.

As part of this study, the researchers analyzed the levels of PFAS in the participants’ blood samples along with the levels of a variety of small molecules that are known to be essential to prenatal development. The researchers then used statistical methods to look at how these chemical differences affected birth weights. The analysis found that PFAS exposures were linked with lower birth weights in babies that African American women delivered. These lower birth weights may have been associated with changes in the levels of a variety of essential metabolites and molecules, including amino acids, lipid/fatty acid, bile acids, and sex hormones.

The results of this study reveal some of the key chemical mechanisms that may be responsible for the effects of PFAS exposure on prenatal development. “The molecular mechanisms and biomarkers presented in this study warrant future investigation in targeted studies,” said Dr. Liang. “These investigations may help develop early detection and intervention strategies in both public health and clinical settings.”

Going forward, the team will take a closer look at how PFAS exposures are reflected in the levels of key small molecules in newborn babies. Additionally, team members hope to expand their chemical analysis in order to get a more holistic view of how PFAS exposures affect prenatal development.

Access the brief flash talk from the authors in the following video:

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Recent ECHO Publication Uses New Tools to Explore the Impact of Chemical Exposures on Pregnancy

Posted on November 18, 2021December 5, 2023 by Jodi Snare

Chemical exposures from the environment can have a profound effect on health outcomes, especially for pregnant mothers and their babies. Prenatal development is a carefully controlled biological process that is sensitive to environmental chemicals and maternal health.

In order to better understand the impact of chemical exposures on prenatal development, ECHO researchers Brett Doherty, PhD, MSPH, and Megan Romano, PhD, MPH of Dartmouth College used emerging technologies to investigate the link between chemical exposures and prenatal chemical processes. Their research, titled “Chemical co-exposures assessed via silicone wristbands and endogenous plasma metabolomics during pregnancy” is published in the Journal of Exposure Science and Environmental Epidemiology.

During this investigation, 177 pregnant women enrolled in the New Hampshire Birth Cohort Study (NHBCS) were given silicone wristbands to wear for a week in the early stages of their pregnancy. These wristbands captured snapshots of the chemical exposures the mothers experienced during pregnancy. Three months later, the researchers collected blood samples from the mothers for further analysis.

This analysis utilized metabolomics, a relatively new technology that involves the quantification of all the small molecule building blocks in a sample as a way to determine what chemical processes are occurring in the system.

“We used new tools to investigate how chemicals can affect important small molecules during pregnancy,” said Doherty, “which provided clues to the impacts of those chemicals on the health of the mother and the baby.”

The researchers found that several of the chemical exposures experienced by women in the study were associated with changes in the relative amounts of different important chemical building blocks. Specifically, many of the exposures, including exposures to the insecticide DEET, were associated with changes in the amounts of various amino acids that make up many of the proteins vital to prenatal development.

These results may provide a useful framework for further investigations into the effects of prenatal chemical exposures. “Future investigations may find it helpful to link the impacts we observed to related health processes and outcomes,” Romano noted.

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ECHO Study Links PFAS Exposure During Pregnancy to Lower Birth Weight for Black Mothers

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ECHO Study Links PFAS Exposure During Pregnancy to Lower Birth Weight for Black Mothers

Authors: Che-Jung Chang, Donghai Liang, et al.

Who sponsored this study?

This work was supported by the Environmental Influences on Child Health Outcomes (ECHO) program Opportunities and Infrastructure Fund, Office of the Director, National Institutes of Health, and the Environmental Protection Agency (USEPA).

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

What were the study results?

Some PFAS exposures were linked to a greater risk of low birth weight for babies that African American women delivered. PFAS exposures were also associated with the changes in the levels of small molecules needed for the baby’s development. These molecules included amino acids, lipid/fatty acids, bile acids, and sex hormones.

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 was the study's impact?

This is one of the first studies researching the connections and relationships between exposures to PFAS, metabolomic changes during the baby’s development, and the baby’s growth. The chemical analysis showed that changes in the levels of the molecules may be responsible for the effects on birth weight. Future studies may target the important chemical mechanisms of the molecules, which may help develop early detection and intervention strategies for babies with low birth weight due to PFAS.

Why was this study needed?

Per- and polyfluoroalkyl substances (PFAS) are called “forever chemicals” because they stay in the environment a long time. PFAS exposures have been linked to adverse pregnancy and birth outcomes, such as lower birth weights, but there is little information on why this relationship exists and how PFAS exposures affect the body. Also, African American women and children are exposed to higher levels of environmental pollutants and have a higher risk of negative birth outcomes, so studies focusing on this population are very important for reducing heath disparities.

Who was involved?

This study included 313 participants enrolled in the Atlanta African American Maternal-Child ECHO cohort between March 2014 and May 2018.

What happened during the study?

Researchers collected blood samples from participants and measured the levels of PFAS and small molecules essential to a baby’s development. Using this information, the researchers calculated how the levels of the molecules changed in response to PFAS exposures and how these exposures affected the birth weight of babies.

What happens next?

The research team is working on additional analyses on the impact of exposures to PFAS before birth and the levels of essential small molecules in newborns. They are also planning to conduct larger analyses in order to get a more holistic view of the connection between PFAS exposures and adverse birth outcomes.

Where can I learn more?

For research updates, follow them on Twitter @donghai_liang, @chejung_chang, @EmoryRollins, and @EmoryHERCULES, and check out the Environmental Metabolomics Research Group’s website.

Access the full journal article, titled “Per- and polyfluoroalkyl substance (PFAS) exposure, maternal metabolomic perturbation, and fetal growth in African American women: A meet-in-the-middle approach” in Environment International.

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

Published November 1, 2021

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See ECHO's PFAS research.

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ECHO Study Links PFAS Exposure During Pregnancy to Lower Birth Weight for Black Mothers