Exposure to Flame-retardant Chemicals During Pregnancy Associated with Differences in Child Growth Patterns

Authors: Anne P. Starling, Jessie P. Buckley, Deborah 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?

Organophosphate esters (OPEs) are chemicals widely used as flame retardants and plastic softeners in a variety of household and industrial products. Pregnant women are commonly exposed to these chemicals. While prior studies have examined the effects of OPE exposure during pregnancy on birth outcomes, less is known about how prenatal exposure to these chemicals affects children’s growth patterns beyond infancy. Understanding how early-life environmental exposures are associated with child growth trajectories is important because childhood growth rates can be linked to later risk of obesity and heart disease. This study specifically examined the relationship between OPE exposure during pregnancy and child height, weight, and body mass index (BMI).

What were the study results?

The study found that exposure to specific OPEs during pregnancy was associated with differences in child growth rates between ages 2 and 10 years. Higher prenatal exposure to bis (1,3-dichloro-2-propyl) phosphate (BDCPP) was associated with faster increases in weight and height during early childhood (ages 2–5). In mid-childhood (ages 6–10), higher prenatal exposure to diphenyl phosphate (DPHP) was associated with faster increases in body mass index and weight. In contrast, prenatal exposure to bis(1-chloro-2-propyl) phosphate (BCPP) was associated with slower growth across multiple periods. Some associations differed by child sex and by maternal pre-pregnancy body mass index.

What was this study's impact?

These findings suggest that exposure to certain flame-retardant chemicals during pregnancy may be associated with children’s growth patterns. Because growth trajectories are linked to future obesity and metabolic health, these results underscore the importance of understanding and potentially reducing exposure to these widely used chemicals during pregnancy.

Who was involved?

The study included 4,566 mother-child pairs from 14 ECHO Cohort Study Sites across the United States. Researchers collected exposure data during pregnancy and collected growth data from ages 2 to 10 years.

What happened during the study?

Researchers measured nine chemical markers of OPE exposure in urine samples collected from pregnant participants. They later collected child weight and height measurements between ages 2 and 10 years, which were used to calculate each child’s BMI. The researchers then used statistical models to examine how prenatal OPE exposure was associated with rates of change in weight, height, and BMI.

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 biological mechanisms linking prenatal OPE exposure to child growth and examine whether reducing exposure during pregnancy could improve long-term child health outcomes. Additional studies may also explore the combined effects of multiple environmental chemical exposures during pregnancy and early childhood on the patterns of child growth patterns.

Where can I learn more?

Access the full journal article, titled “Gestational exposure to organophosphate ester flame retardants and child growth in weight, height, and body mass index at age 2-10 years: the Environmental influences on Child Health Outcomes Program” 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.

Read the associated article.

Download this summary

Exposure to Flame-retardant Chemicals During Pregnancy Associated with Differences in Child Growth Patterns

Exposure to Flame-retardant Chemicals During Pregnancy Linked to Differences in Child Growth Patterns

Posted on April 8, 2026April 8, 2026 by Jodi Snare

Prenatal exposure to certain flame-retardant chemicals may be associated with differences in how children grow from early childhood through age 10, according to a recent ECHO Cohort study by Anne P. Starling, PhD, and Jessie P. Buckley, PhD, of UNC Chapel Hill, and Deborah Bennett, PhD, of University of California, Davis.

Organophosphate esters (OPEs) are widely used as flame retardants and plastic softeners in a variety of household and industrial products. Because these chemicals can be found in everyday environments, pregnant women are commonly exposed. While previous research has examined OPE exposure during pregnancy in relation to birth outcomes, less is known about whether prenatal exposure may be linked to children’s growth patterns beyond infancy.

To better understand these potential relationships, researchers measured nine chemical markers of OPE exposure in urine samples collected from pregnant participants. They then analyzed children’s weight and height measurements collected between ages 2 and 10 years and calculated body mass index (BMI). Using statistical models, the team examined whether prenatal OPE exposure was associated with differences in the rate of change in children’s weight, height, and BMI over time.

Researchers looked at 4,566 mother-child pairs from 14 ECHO Cohort Study Sites across the United States.

Key Takeaways :

Prenatal exposure to specific OPEs was associated with differences in child growth rates between ages 2 and 10.
Higher prenatal exposure to bis (1,3-dichloro-2-propyl) phosphate (BDCPP) was associated with faster increases in weight and height during early childhood (ages 2–5).
In mid-childhood (ages 6–10), higher prenatal exposure to diphenyl phosphate (DPHP) was associated with faster increases in BMI and weight.
Prenatal exposure to bis(1-chloro-2-propyl) phosphate (BCPP) was associated with slower growth across multiple periods.
Some associations differed by child sex and by maternal pre-pregnancy body mass index.

“This work increases our understanding of the potential long-term effects on child health from typical levels of exposure to these chemicals during pregnancy. The results may inform future guidance on the production and use of OPEs,” said Dr. Starling.

Additional research could help clarify the biological mechanisms involved and explore whether reducing exposure during pregnancy could support long-term child health.

This collaborative research, titled “Gestational exposure to organophosphate ester flame retardants and child growth in weight, height, and body mass index at age 2-10 years: the Environmental influences on Child Health Outcomes Program,” is published in Environmental Research.

Prenatal Exposure to Certain Flame Retardants Associated with Autism-Related Traits, ECHO Study Finds

Posted on July 18, 2025July 18, 2025 by Jodi Snare

High exposure to some organophosphate esters (OPEs) during pregnancy was associated with higher scores for increased autism-related traits and greater odds of an autism diagnosis in children, according to research from the Environmental influences on Child Health Outcomes (ECHO) Program led by Jennifer Ames, PhD, and Lisa Croen, PhD of Kaiser Permanente Northern California. Overall, the study found generally small associations between three OPEs and child autism-related outcomes.

OPEs, often called “regrettable replacements,” replaced polybrominated diphenyl ethers (PBDEs) in the mid-2000s as flame retardants and plastic softeners, and are now found in furniture, electronics, construction materials, textiles, and infant products. Despite their widespread use, little is known about their effects on child development.

In this study, ECHO researchers analyzed urine samples from 4,159 pregnant mothers for nine OPE biomarkers and assessed children’s autism-related traits using the Social Responsiveness Scale (SRS), along with autism diagnoses.

Key findings include:

High exposure to bis(butoxyethyl) phosphate (BBOEP) was associated with higher autism-related trait scores and greater odds of an autism diagnosis, particularly among boys.
Bis(1-chloro-2-propyl) phosphate (BCPP) exposure was linked to higher autism-related trait scores.
High exposure to bis(2-chloroethyl) phosphate (BCETP) was associated with lower odds of an autism diagnosis.

“Organophosphate esters are widely used, but their potential effects on neurodevelopment are understudied. Our findings highlight the need for further research to understand their long-term effects on child neurodevelopment,” said Dr. Ames.

The study included children born from 2006 to 2020 at 15 ECHO Cohort sites across the United States.

This collaborative research, titled “Exposure to organophosphate ester flame retardants and plasticizers during pregnancy and autism-related outcomes in the ECHO Cohort,” is published in Environmental Health Perspectives.

Prenatal Exposure to Organophosphate Esters Associated with Increased Autism-Related Outcomes, ECHO Study Finds

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Prenatal Exposure to Organophosphate Esters Associated with Increased Autism-Related Outcomes, ECHO Study Finds

Author(s): Jennifer Ames, 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?

Organophosphate esters (OPE) replaced harmful polybrominated diphenyl ethers (PBDEs) as flame retardants and plastic softeners in the mid-2000s. They are now present in various household and industrial products, including polyurethane foam, furniture, electronics, construction materials, infant products, textiles, and fabrics. Health officials and researchers currently know little about how OPEs affect child development. Earlier studies have suggested a link between prenatal exposure to these chemicals and birth outcomes and cognitive and behavioral problems in children. This study investigated the potential effects of prenatal exposure to nine OPEs on child autism-related outcomes.

What were the study results?

The study found generally small associations between three OPEs and child autism-related outcomes. Specifically, high exposure to bis(butoxyethyl) phosphate (BBOEP) was associated with higher scores for autism-related traits and greater odds of autism diagnosis. Another OPE, bis(1-chloro-2-propyl) phosphate (BCPP) showed associations with higher autism-related trait scores. High exposure to bis(2-chloroethyl) phosphate (BCETP) was associated with lower odds of autism diagnosis. The study also found that the association between BBOEP and higher autism-related traits scores was stronger in boys than in girls.

What was the study's impact?

This study underscores the need to better understand and address the potential developmental toxicity of these widely used chemicals.

Who was involved?

The study included 4,159 mother-child pairs with children born from 2006 to 2020 from 15 study sites in the ECHO Cohort.

What happened during the study?

Researchers analyzed urine samples from pregnant mothers for nine OPE biomarkers. The researchers then assessed child autism-related traits via the Social Responsiveness Scale (SRS) and collected information on whether they received a clinical autism diagnosis to examine associations between prenatal OPE exposure and child neurodevelopment.

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 replicate these findings in different populations and use multiple measures of OPEs throughout pregnancy to better understand the critical exposure windows and long-term effects of OPEs on child neurodevelopment. Additionally, further studies could help researchers explore the potential sex-specific effects of prenatal OPE exposure.

Where can I learn more?

Access the full journal article, titled “Exposure to organophosphate ester flame retardants and plasticizers during pregnancy and autism-related outcomes in the ECHO Cohort,” in Environmental Health Perspectives.

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

Published June 11, 2025

Read the related research alert.

Download this summary

Prenatal Exposure to Organophosphate Esters Associated with Increased Autism-Related Outcomes, ECHO Study Finds

NIH Study Finds Exposure to Flame-Retardant Chemicals During Pregnancy Was Associated with Varying Childhood Obesity Risks

Posted on November 4, 2024August 27, 2025 by Jodi Snare

FOR IMMEDIATE RELEASE

Study reveals a complex link between pregnancy exposure to common chemicals and childhood obesity, researchers say.

Exposure to organophosphate esters (OPEs)—chemicals found in everyday products that use plastics and flame retardants—during pregnancy may have varying effects on the risks of childhood obesity, according to a new study funded by the Environmental influences on Child Health Outcomes (ECHO) Program at the National Institutes of Health.

The study found that children aged 5 to 10 years who were exposed to higher levels of dibutyl phosphate and di-isobutyl phosphate (DBUP/DIBP) during pregnancy had a 14% greater risk of developing obesity compared to those with the lowest exposure levels. In contrast, children whose mothers had higher exposure levels of bis (1,3-dichloro-2-propyl) phosphate (BDCPP) during pregnancy had a 15% lower risk of developing obesity than those with the lowest levels of exposure.

“We are just beginning to understand how OPE exposure might be connected to obesity. Our findings suggest that the relationship between OPE exposure during pregnancy and childhood obesity is complicated, and more research is needed to look at a wider range of OPE chemicals,” said Assiamira Ferrara, MD, PhD, senior research scientist at Kaiser Permanente Northern California Division of Research.

These chemicals are OPEs, which replaced polybrominated diphenyl ethers (PBDE) as flame retardants and plastic softeners in the mid-2000s. Studies in toxicology and epidemiology suggest that these substances can interfere with hormone systems and may be linked to obesity.

The study involved 5,087 mother-child pairs from 14 ECHO Cohort Study Sites. Researchers measured the levels of OPEs in the mother's urine during pregnancy and their children's body mass index (BMI) during infancy up to age 10. The participants were pregnant between 2006 and 2020 when OPEs were being rolled out to replace PBDEs.

“These findings underscore the need for further research to inform public health programs and regulatory policies aimed at mitigating childhood obesity risks from environmental chemical exposures,” said Alicia K. Peterson, PhD staff scientist at Kaiser Permanente Northern California Division of Research.

Researchers across the ECHO Cohort reviewed and analyzed data for this study. This collaborative research was published in Environment International.

Peterson, AK, et al. “Gestational Exposure to Organophosphate Ester Flame Retardants and Risk of Childhood Obesity in the Environmental influences on Child Health Outcomes.” Environment International. DOI: 10.1016/j.envint.2024.109071.

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About ECHO: Launched in 2016, the Environmental influences on Child Health Outcomes (ECHO) Program is a research program in the Office of the Director at the NIH with the mission to enhance the health of children for generations to come. ECHO investigators study the effects of a broad range of early environmental influences on child health and development. For more information, visit echochildren.org.

About the NIH: NIH, the nation’s medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information, visit www.nih.gov.

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ECHO Study Investigates Exposure to Flame-Retardants During Pregnancy and Childhood Obesity Risk

Authors: Alicia K. Peterson, Assiamira Ferrara, 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?

Organophosphate esters (OPE) replaced polybrominated diphenyl ethers (PBDEs) as flame retardants and plastic softeners in the mid-2000s. They are now present in various household and industrial products, including polyurethane foam, furniture, electronics, construction materials, infant products, textiles, and fabrics. Health officials have raised concerns about their impact on hormone systems and potential links to obesity. This study looked at whether the levels of OPEs found in a mother's urine during pregnancy were associated with a higher risk of obesity in her child.

What were the study results?

The study found varying associations between gestational OPE exposure and childhood obesity. The study found that children aged 5 to 10 years who were exposed to higher levels of dibutyl phosphate and di-isobutyl phosphate (DBUP/DIBP) during their mother’s pregnancy had a 14% greater risk of developing obesity compared to those with the lowest exposure levels. In contrast, children whose mothers had higher exposure levels of bis (1,3-dichloro-2-propyl) phosphate (BDCPP) during their mother’s pregnancy had a 15% lower risk of developing obesity than those with the lowest levels of exposure. Researchers measured for evidence of nine different OPEs in pregnant participants’ urine. Evidence of exposure to DBUP/DIBP and BDCPP was present in more than 80% of the samples. No association with obesity risk was observed for the rest of the OPEs measured.

What was this study's impact?

The study highlights the potential public health issue of gestational OPE exposure and its association with childhood obesity. It suggests the need for further investigation across a broad range of OPE exposures and could inform potential regulations on the manufacture and use of OPEs.

Who was involved?

The study involved 5,087 individuals from 14 ECHO Cohort Study Sites. The study population was geographically, racially, and ethnically diverse.

What happened during the study?

Researchers measured OPE exposure in the urine samples of pregnant participants between 2006 and 2020 and collected BMI measurements for the children from infancy to age 10 years.

Note: 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 help researchers better understand the associations between gestational exposure across a broad range of OPE exposures and childhood obesity.

Where can I learn more?

Access the full journal article, “Gestational Exposure to Organophosphate Ester Flame Retardants and Risk of Childhood Obesity in the Environmental influences on Child Health Outcomes Consortium,” 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 October 17, 2024

Read the associated press release.

Download this summary

ECHO Study Investigates Exposure to Flame-Retardants During Pregnancy and Childhood Obesity Risk