pregnancy

Perceived Stress During Pregnancy Associated with Autism-related Traits in Children

Posted on by Jodi Snare

Higher perceived stress during pregnancy may be associated with greater severity of autism-related traits in children, according to a recent ECHO Cohort study led by Luke Grosvenor, PhD, of Kaiser Permanente Northern California.

Many mothers experience higher levels of stress and other mental health challenges during pregnancy. Previous studies have found that pregnancy stress may be associated with increased risk of autism spectrum disorder (ASD) in children, but these studies have mostly focused on the occurrence of isolated adverse or stressful events that occur in the mother’s life during pregnancy. Fewer studies have measured general perceived stress among mothers during pregnancy. To better understand whether this prenatal exposure may be associated with severity of autism-related traits in children, researchers collected information from over 4,000 mothers and their children enrolled in 20 ECHO Cohort Study Sites across the United States.

Key Takeaways include:

  • Higher perceived stress during pregnancy was associated with slightly more severe autism‑related traits in children.
  • At higher prenatal perceived stress levels, children showed slightly higher scores on tests measuring social and behavioral traits related to autism. Children whose mothers had either moderate or high categorical stress scored higher than those whose mothers reported low or no stress.
  • The link between pregnancy stress and autism‑related traits did not differ between boys and girls.
  • The relationship between prenatal stress and autism‑related traits remained consistent even when the researchers accounted for mothers’ co-occurring prenatal depressive symptoms.
  • Stress during pregnancy is normal and common to experience. While the results of this study indicate that there may be a small association between pregnancy stress and autism-related traits, they do not imply that stress during pregnancy causes autism spectrum disorder or autism-related traits to occur in children.

“This study provides evidence for small yet significant associations between higher prenatal perceived stress and greater severity of autism-related traits,” said Dr. Grosvenor. “These results could have implications for prenatal mental health screening and behavioral interventions aimed at improving child outcomes.”

Future studies could help researchers better understand the specific periods during pregnancy during which stress may have the greatest association with child health and development and how other related social and emotional factors may influence this effect.

This collaborative research, titled “Associations between Prenatal Perceived Stress and Child Autism-Related Traits in the ECHO Cohort,” is published in The Journal of Pediatrics.

Read the research summary.

 

Smoking During Pregnancy Linked to Mental Health Challenges in Children, ECHO Study Finds

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Smoking During Pregnancy Linked to Mental Health Challenges in Children, ECHO Study Finds

Authors: Kristine Marceau, 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?

Previous research has shown that children whose mothers smoked during pregnancy are more likely to develop behavior problems, particularly difficulties with acting out or following rules. However, it has been less clear whether prenatal smoking also increases the risk of mental health problems generally, or if it’s a specific risk for difficulties with acting out or following rules alone. Researchers from this study wanted to understand whether prenatal smoking contributes to co-occurring emotional and behavioral symptoms or specifically behavioral symptoms, and whether its effects differ by age or sex. This study helps address these gaps by examining which developmental periods may be especially sensitive to prenatal smoking effects and whether boys or girls are more vulnerable.

 

What were the study results?

Children exposed to smoking before birth were more likely experience multiple co‑occurring emotional and behavioral symptoms, and also to show more externalizing problems—such as attention problems, aggressive behavior, and rule‑breaking. These associations were observed across nearly all age groups and remained even after accounting for family history, background, and other exposures.

The strongest effects on mental health symptoms were seen in early childhood (under age 7) and early puberty (ages 9 to 12). There were very few differences between boys and girls. Only at ages 13-14 did boys seem to have more co‑occurring emotional and behavioral symptoms and externalizing-specific problems than girls. In general, both boys and girls were affected in similar ways.

 

What was the study's impact?

These results suggest that prenatal exposure to nicotine may increase the risk of mental health and behavioral problems. Because this study included a large number of children from different backgrounds, it helps clarify past research and contributes new insight about when certain problems tend to appear and how different symptoms may occur together.

 

Who was involved?

The study included 16,335 children and adolescents ages 1 to 18 from 55 U.S. ECHO Cohort Study Sites. All participants completed Child Behavior Checklist (CBCL) and Strengths and Difficulties Questionnaire (SDQ) behavioral assessments.

 

What happened during the study?

Researchers gathered standardized information about children’s behavior and created a simple score to show how many symptoms a child had and whether those symptoms were more emotional (such as sadness, anxiety) or behavioral (such as acting out, rule breaking). They then looked at these patterns across different age groups, while taking into account important factors such as the mother’s age and education, family mental health history, and exposure to smoke or other substances during and after pregnancy.

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 work could help researchers understand how timing, dose, and frequency of smoking during pregnancy correlates with child mental health. Future research could also use methods to separate the effects of family background from the effects of smoking itself and look more closely at how nicotine and other chemicals in smoke might affect children’s development.

 

Where can I learn more?

Access the full journal article, titled “Prenatal Smoking and Child Psychopathology Associations by Age and Sex in the ECHO Cohort,” in Development and Psychopathology.

 

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

Published April 6, 2026

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Smoking During Pregnancy Linked to Mental Health Challenges in Children, ECHO Study Finds

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Prenatal Smoking Associated with Higher Risk of Mental Health Challenges in Children

Posted on by Jodi Snare

Mother and toddler laughingChildren exposed to maternal smoking before birth are more likely to experience behavioral and mental health challenges, according to a large study funded by the National Institutes of Health’s Environmental influences on Child Health Outcomes (ECHO) Program.

While previous research had linked prenatal smoking to acting out or rule-breaking, it was less clear whether smoking during pregnancy also affects broader mental health outcomes and whether effects differ by sex.  The new study sheds light on these questions, examining thousands of children across the U.S. and identifying periods when exposure may be most impactful.

“These findings show that prenatal nicotine exposure can affect more than just acting-out types of behavior problems—it can influence children’s overall mental health and experiences of both emotional and behavioral problems at the same time,” said Kristine Marceau, PhD, of Purdue University. “Understanding when kids are most vulnerable can help families and healthcare providers provide support at the right time.”

Researchers analyzed data from 16,335 children ages 1 to 18 from 55 ECHO Cohort Study Sites. Behavioral assessments measured emotional and behavioral symptoms using standardized questionnaires.

Key Findings

  • Widespread Impact: Children exposed to prenatal smoking were more likely to have multiple mental health or behavioral symptoms at the same time.
  • Critical Windows: The strongest effects appeared in early childhood (under age 7) and early puberty (ages 9–12).
  • Similar Effects for Boys and Girls: Both sexes were affected in comparable ways, with slightly higher symptom levels in boys only at ages 13–14.
  • Independent of Family Background: Associations persisted even after considering family history and other environmental factors, such as maternal age, education, and additional substance exposures.

Future studies could take a closer look at the timing, amount, and frequency of smoking during pregnancy. Researchers could also work to better understand which effects are due to smoking itself—rather than other family factors—and how nicotine and other chemicals in smoke may affect how children grow and develop.

This collaborative research, titled “Prenatal Smoking and Child Psychopathology Associations by Age and Sex in the ECHO Cohort,” is published in Development and Psychopathology.

Media Contacts

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

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

Connect With Us

echo connector

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 the ECHO Program on LinkedIn and X for the latest updates.

Perceived Stress During Pregnancy Associated with Autism-related Traits in Children, ECHO Study Finds

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Perceived Stress During Pregnancy Associated with Autism-related Traits in Children, ECHO Study Finds

Authors: Luke Grosvenor, 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?

Many mothers experience higher levels of stress and other mental health challenges during pregnancy. Previous studies have found that pregnancy stress may be associated with increased risk of autism spectrum disorder (ASD) in children, but these studies have mostly focused on the occurrence of isolated adverse or stressful events that occur in the mother’s life during pregnancy. Fewer studies have measured general perceived stress among mothers during pregnancy. This study examined the potential association between perceived stress during pregnancy and autism-related traits in children and evaluated how that association may differ according to the child’s sex or the mother’s experience of depression during pregnancy.

 

What were the study results?

Higher perceived stress during pregnancy was associated with slightly more severe autism‑related traits in children. At higher prenatal perceived stress levels, children showed slightly higher scores on tests measuring social and behavioral traits related to autism. Children whose mothers had either moderate or high categorical stress scored higher than those whose mothers reported low or no stress. The link between pregnancy stress and autism‑related traits did not differ between boys and girls. The relationship between prenatal stress and autism‑related traits remained consistent even when the researchers accounted for mothers’ co-occurring prenatal depressive symptoms.

 

What was the study's impact?

Stress during pregnancy is normal and common to experience. While the results of this study indicate that there may be a small association between pregnancy stress and autism-related traits, they do not imply that stress during pregnancy causes autism spectrum disorder or autism-related traits to occur in children.

 

Who was involved?

The study included 4,115 mother–child pairs from 20 ECHO Cohort Study Sites across the United States. Children ranged in age from about 2.5 to 18 years old.

 

What happened during the study?

Mothers reported their stress levels during pregnancy using a standard questionnaire. Later, parents reported on their children’s autism-related traits using a validated survey. Researchers analyzed the data using statistical models that accounted for factors such as child age, sex, and study site.

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

 

What happens next?

Future studies could help researchers better understand the specific periods in pregnancy when stress may have the greatest association with child health and development and how other related social and emotional factors may influence this effect.

 

Where can I learn more?

Access the full journal article, titled “Associations between Prenatal Perceived Stress and Child Autism-Related Traits in the ECHO Cohort,” in The Journal of Pediatrics.

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

Published March 2, 2026

Access the associated article.

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Perceived Stress During Pregnancy Associated with Autism-related Traits in Children, ECHO Study Finds

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Early‑Pregnancy Exposure to Fine Particulate Air Pollution Linked to Lower Birthweight in New ECHO Study

Posted on by Jodi Snare

Exposure to fine particulate matter (PM2.5)—tiny inhalable particles found in air pollution—during the earliest weeks of pregnancy was associated with babies being slightly smaller for gestational age, according to a new ECHO Cohort study led by Whitney Cowell, MPH, PhD, of NYU Langone Health.

Low birthweight is a known risk factor for a range of health issues in infancy and later life. Prior studies have shown links between PM2.5 exposure and birth outcomes, but many examined average exposure over time, leaving uncertainty about which specific weeks may be most harmful. This study aimed to pinpoint sensitive windows in early pregnancy when exposure may have the greatest impact.

Using data from 16,868 pregnant women at ECHO Cohort sites across the United States, researchers estimated weekly PM2.5 exposure during pregnancy and analyzed how it related to birthweight. They also evaluated whether associations varied by infant sex, parent race and ethnicity, or region the mother lived in during pregnancy.

Key takeaways:

  • Higher PM5 exposure during early pregnancy—particularly weeks 1–5—was associated with lower birthweight.
  • Male newborns appeared more sensitive to these early‑pregnancy exposures than female newborns.
  • Effects varied by U.S. region, with stronger associations in the Northeast, South, and Midwest, and weaker effects in the West—likely due to differences in particle types.

“The findings from this study support the need to periodically reevaluate National Ambient Air Quality Standards to ensure recommendations protect the health of the most sensitive subgroups, including pregnant women and fetuses,” said study author Dr. Cowell.

Understanding precisely when fetuses are most vulnerable to air pollution can help guide public health strategies and shape future investigations into biological mechanisms. The findings highlight the need for closer examination of pollutant composition, maternal factors, and other influences—such as diet or lifestyle—that may modify risk.

This collaborative research, titled “PM2.5 in relation to birthweight: exploring windows of susceptibility in the ECHO Cohort,” was published in JAMA Network Open.

Maternal Smoking During Pregnancy May Be Linked to Higher Blood Pressure in Children

Posted on by Jodi Snare

Maternal smoking during pregnancy may be associated with higher blood pressure and increased risk of hypertension in children, according to a new ECHO Cohort study led by Lyndsey Shorey-Kendrick, PhD, of Oregon Health & Science University and Christine Ladd-Acosta, PhD, of Johns Hopkins University.

Blood pressure that is higher than normal in childhood, including diagnosed high blood pressure, can increase the risk of developing high blood pressure later in life, a major risk factor for heart disease. Previous studies examining prenatal smoking exposure and childhood blood pressure have produced mixed findings. Many relied on self-reported smoking or focused only on systolic blood pressure, the top number in a blood pressure reading that reflects pressure when the heart beats. Fewer studies examined diastolic blood pressure, the bottom number that reflects pressure when the heart rests between beats.

To address these gaps, researchers used data from the ECHO Cohort to examine how smoking during pregnancy was related to both systolic and diastolic blood pressure in children. The study included 13,120 children born between 1999 and 2020 from 52 ECHO Cohort Study Sites across the United States, including Puerto Rico. Researchers assessed smoking during pregnancy using self-reports, medical records, and urine samples collected during pregnancy, and measured children’s blood pressure between ages 3 and 18.

Children whose mothers smoked during pregnancy were more likely to have higher blood pressure and a greater risk of hypertension. The study distinguished between “any reported smoking,” which is based on what mothers shared in surveys or medical records, and “active smoking,” which is confirmed by a urine test for cotinine, a marker of recent tobacco use. Active smoking during pregnancy was linked to even higher blood pressure in children.

Key Takeaways include:

  • Self-reported smoking during pregnancy was associated with higher diastolic blood pressure and increased risk of childhood hypertension.
  • Associations were stronger among female children and tended to increase with age.
  • Active smoking during pregnancy, identified using urine samples, was associated with higher systolic and diastolic blood pressure and greater risk of hypertension.
  • Self-reported secondhand smoke exposure during pregnancy was not associated with higher blood pressure in children.

“These findings suggest that reducing maternal smoking during pregnancy could lower hypertension rates in children and adults,” said Dr. Ladd-Acosta.

This collaborative research, titled “Association of Maternal Smoking During Pregnancy with Childhood Blood Pressure and Hypertension in the ECHO Cohort,” is published in Circulation.

About ECHO
The ECHO Cohort Consortium is a research program supported by the National Institutes of Health (NIH) with the mission to enhance the health of children for generations to come. ECHO Cohort investigators study the effects of a broad range of early environmental influences on child health and development. For more information, visit echochildren.org.

Media Contacts

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

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

Connect With Us

echo connector

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 the ECHO Program on LinkedIn and X for the latest updates.

Maternal Smoking During Pregnancy May Be Associated with Increased Childhood Blood Pressure, ECHO Study Finds

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Maternal Smoking During Pregnancy May Be Associated with Increased Childhood Blood Pressure, ECHO Study Finds

Authors: Lyndsey E. Shorey-Kendrick, Christine Ladd-Acosta, 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?

Blood pressure that is higher than normal in childhood, including diagnosed high blood pressure, can increase the risk of developing high blood pressure as an adult, which is a major risk factor for heart disease. Past studies looking at smoking during pregnancy and children’s blood pressure have had mixed results. Many relied on parents’ self-reports of smoking or focused only on systolic blood pressure, the top number in a blood pressure reading that reflects pressure when the heart beats. Fewer studies examined diastolic blood pressure, the bottom number that reflects pressure when the heart rests between beats.

To better understand these links, researchers needed a large U.S. study that included objective lab measures of smoking during pregnancy. Using data from the ECHO Cohort, researchers examined how smoking during pregnancy was related to both systolic and diastolic blood pressure in children.

 

What were the study results?

Children whose mothers smoked during pregnancy—whether occasionally or regularly—were more likely to have higher blood pressure and a greater risk of hypertension (higher than normal blood pressure at three or more doctors’ visits). The study distinguished between “any reported smoking,” which is based on what mothers shared in surveys or medical records, and “active smoking,” which is confirmed by a urine test for cotinine, a marker of recent tobacco use. Active smoking, identified by these lab tests, was linked to even higher blood pressure in children.

 

What was the study's impact?

This study reinforces that smoking during pregnancy is a risk factor for increased childhood blood pressure and hypertension and underscores the importance of smoking reduction during pregnancy for children’s heart health. The use of objective laboratory measures strengthens these findings and more accurately identifies children at risk.

 

Who was involved?

The study included 13,120 children born between 1999 and 2020 from 52 ECHO Cohort Study Sites in the U.S. All children had at least one blood pressure measurement taken between the ages of 3 and 18 years. A nearly equal number of male and female children from a range of sociodemographic groups were included.

 

What happened during the study?

Researchers collected smoking data from pregnant women using self-report surveys, medical records, and/or urine specimens. Children’s blood pressure was measured when they were between 3 and 18 years of age. Using these measurements, the researchers performed a statistical analysis to compare blood pressure levels between children exposed to smoking during pregnancy and children not exposed. The researchers also assessed whether there were any differences in the relationships between smoking and blood pressure by child sex.

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?

More studies could help researchers better understand how smoking during pregnancy may contribute to higher blood pressure in children. Future studies could use biological measures of prenatal smoke exposure, which may help capture individual differences in how children are affected and make it easier to identify those at higher risk

 

Where can I learn more?

Access the full journal article, titled “Association of Maternal Smoking During Pregnancy with Childhood Blood Pressure and Hypertension in the ECHO Cohort,” in Circulation.

 

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

Published February 16, 2026

Read the related press release.

Download this summary

Maternal Smoking During Pregnancy May Be Associated with Increased Childhood Blood Pressure, ECHO Study Finds

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Exposure to PM2.5 Air Pollution During Pregnancy Associated with Lower Birthweight, ECHO Study Finds

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Exposure to PM2.5 Air Pollution During Pregnancy Associated with Lower Birthweight, ECHO Study Finds

Authors: Daniel Enquobahrie, Adaeze Wosu Nzegwu, 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?

Exposure to fine particulate matter (PM2.5)—very small inhalable particles found in air pollution—is widespread and linked to various health risks. Previous research has examined the effects of PM2.5 exposure during pregnancy on birth outcomes, but gaps remain. More research is needed to understand whether there are critical windows during pregnancy when PM2.5 exposure is most impactful. This study aimed to address these gaps by investigating how the timing of PM2.5 exposure affects birth outcomes, such as birthweight and length of pregnancy, using data from the ECHO Cohort’s large, multi-site study structure. It also explored whether associations differ by infant sex and maternal race and ethnicity.

 

What were the study results?

Exposure to higher levels of PM2.5 during the first weeks of pregnancy was linked to babies being slightly smaller at birth and having a higher chance of being born small for their gestational age (smaller than average for the length of the pregnancy). There was no significant association between PM2.5 exposure and shorter pregnancies or preterm birth. For baby girls, higher PM2.5 exposure in early pregnancy seemed to affect their birth size more than for baby boys, suggesting that the baby's sex can make a difference in how air pollution affects growth. The effects of PM2.5 on birth outcomes like being born prematurely, birth size, or being small for gestational age varied depending on the mother's race and ethnicity.

 

What was this study's impact?

This study on PM2.5 exposure during early pregnancy and birth outcomes can inform ongoing discussions on strategies for reducing PM2.5 air pollution.

 

Who was involved?

The study included 19,108 mother-infant pairs from 51 ECHO Cohort Study Sites across the United States.

 

What happened during the study?

Researchers estimated PM2.5 exposure for each pregnant participant based on residential address, accounting for moves during pregnancy. The researchers then assessed exposure for the whole pregnancy, each trimester, and specific windows in the first trimester. The researchers collected information on birth outcomes, including length of pregnancy and birthweight.

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 research could help investigators better understand the mechanisms underlying differences in air pollution vulnerability by infant sex, and by maternal race and ethnicity. Additional studies could also help researchers understand how other factors, such as diet and lifestyle, influence the relationship between PM2.5 exposure and birth outcomes.

 

Where can I learn more?

Access the full journal article, titled “Gestational fine particulate matter exposure and perinatal outcomes in the ECHO cohort: Associations across pregnancy windows,” in Environmental Research.

 

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

 

Published March 1, 2026

Read the associated article.

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Exposure to PM2.5 Air Pollution During Pregnancy Associated with Lower Birthweight, ECHO Study Finds

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Pre-, Peri-, and Postnatal

ECHO Study Finds Exposure to Air Pollution During Early Pregnancy Associated with Lower Birthweight

Posted on by Jodi Snare

Exposure to fine particulate matter (PM2.5)—very small inhalable particles found in air pollution—during early pregnancy was associated with babies being slightly smaller at birth, according to a new ECHO Cohort study led by Daniel Enquobahrie, PhD, MD, MPH of the University of Washington School of Public Health and Adaeze Wosu Nzegwu, PhD, MPH of Johns Hopkins Bloomberg School of Public Health.

Exposure to PM2.5 is widespread and linked to various health risks, including respiratory, cardiovascular, and metabolic diseases. Previous research has examined the effects of PM2.5 exposure during pregnancy on birth outcomes, but gaps remain. More research is needed to understand whether there are critical windows during pregnancy when PM2.5 exposure is most impactful. For this study, researchers used information from 19,108 mothers and their babies from 51 ECHO Cohort Study Sites across the United States to evaluate how timing of PM2.5 exposure affects birth outcomes. They also explored whether associations differ by infant sex and maternal race and ethnicity.

Key Takeaways include:

  • Exposure to higher levels of PM2.5 during the first weeks of pregnancy was linked to babies being slightly smaller at birth and having a higher chance of being born small for their gestational age (smaller than average for the length of pregnancy).
  • There was no significant association between PM2.5 exposure and shorter pregnancies or preterm birth.
  • For baby girls, higher PM2.5 exposure in early pregnancy seemed to affect their birth size more than for baby boys, suggesting that the baby's sex can make a difference in how air pollution affects growth.
  • The effects of PM2.5 on birth outcomes like being born prematurely, birth size, or being small for gestational age varied depending on the mother's race and ethnicity.

“This study on PM2.5 exposure during pregnancy and birth outcomes can inform ongoing discussions on regulations that impact PM2.5 exposure, such as traffic-related air pollution.” said Dr. Enquobahrie.

Further research could help investigators better understand the mechanisms underlying differences in air pollution vulnerability by infant sex, and by maternal race and ethnicity. Additional studies could also help researchers understand how other factors, such as diet and lifestyle, influence the relationship between PM2.5 exposure and birth outcomes.

This collaborative research, titled “Gestational fine particulate matter exposure and perinatal outcomes in the ECHO cohort: Associations across pregnancy windows,” is published in Environmental Research.

Read the research summary.

Exposure to Certain Flame-Retardant Chemicals During Pregnancy Associated with Child Cognition

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 slightly lower scores on tests of mental skills in young children, according to a new ECHO Cohort study led by Akhgar Ghassabian, MD, PhD of New York University Grossman School of Medicine.

Previous studies have suggested that OPEs may affect child brain development. With increasing human exposure to these chemicals, especially during sensitive periods like pregnancy, there has been concern about the potential impact on child cognitive development. This study included data from 831 mother-child pairs from three ECHO Cohort Study Sites in the United States. When pregnant women had higher urine levels of diphenyl phosphate (DPHP), a compound produced during the breakdown of certain OPEs in the human body, their children tended to have slightly lower scores on tests of mental skills at ages 4–6. This pattern was seen in boys and girls. Unexpectedly, boys whose mothers had higher levels of certain other chemicals linked to OPE exposure during pregnancy scored higher on these tests, but this was not true for girls.

“Results from this study suggest that OPE exposure during pregnancy may be associated with minor decreases in cognitive functioning in offspring,” said Dr. Ghassabian. “Considering that DPHP is a widely detected OPE metabolite in the U.S. population, the overall population impact of this modest effect size can be significant.”

Additional studies could help researchers better understand the biological pathways underlying these associations. Additional studies could also help clarify the association between some chemical markers of OPE exposure and higher cognitive scores among boys.

This collaborative research, titled “Prenatal exposure to organophosphate ester flame retardants and child cognition: findings from the Environmental influences on Child Health Outcomes cohort,” is published in Environmental Pollution. Read the research summary.