Child Body Mass Index Dropped After Healthy, Hunger-Free Kids Act in Schools

Author(s): Aruna Chandran, Emily Knapp, 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?

The study showed an overall decrease in BMI in the first few years following the implementation of the HHFKA compared to BMI in the decade prior to the program. Among children ages 12-18 years, who may have more autonomy in purchasing their own lunches or snacks during the school day, BMI decreased from year to year following the start of the HHFKA. This was a reversal of the trends seen during the decade before the program, during which adolescent BMI was increasing each year. This study also supported findings from previous studies that found the HHFKA had a positive effect on the health of children from lower-income families by contributing to an annual decrease in their 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 was the study's impact?

The National School Lunch Program and School Breakfast Program (NSLP) provides free or low cost meals to over 30 million children annually, providing an estimated 50% of students’ caloric intake each school day. This study found that the HHFKA was associated with decreases in child and adolescent BMI. Increasing BMI trends before the HHFKA was implemented were stopped or even reversed in several populations after the law was implemented, which could critically influence their long-term health. The study also found that the implementation of the HHFKA decreased BMI of children from lower-income families, who are more likely to participate in the NSLP and are at higher risk of obesity. Accessibility to school meals and snacks represents a key opportunity for intervention to combat the childhood obesity epidemic.

Why was this study needed?

Childhood obesity is a serious health concern with long-term consequences for health and quality of life. Nearly 1 in 5 children in America is obese. The 2010 Healthy, Hunger-Free Kids Act (HHFKA) was the first legislation passed in nearly 3 decades aimed at improving the nutritional quality of breakfast, lunch, and snacks sold at schools. Studies have shown that the HHFKA has improved the quality of school meals without affecting cost or program participation, but only a few small studies have explored whether the HHFKA reduced body mass index (BMI) in children over time.

Who was involved?

This study included 14,121 children from the ECHO Program between the ages of 5 and 18 who had at least one height and weight measurement recorded between January 2005 to March 2020.

What happened during the study?

Researchers used height and weight measurements from children across 50 ECHO cohorts to calculate each child’s BMI and adjusted each measurement based on age and sex. They used these data to evaluate yearly BMI trends from before and after the implementation of the Healthy, Hunger Free Kids Act in September 2016.

What happens next?

Future studies are needed to further explore and verify the effect of improving the nutritional quality of school meals on childhood obesity. In addition, policymakers could use data from studies like this to evaluate policies related to improving the nutritional quality of meals provided in schools.

Where can I learn more?

Access the full journal article, titled “Changes in Body Mass Index Among School-Aged Children Following Implementation of the Healthy, Hunger-Free Kids Act,” in JAMA Pediatrics.

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

Published: February 13, 2023

Access the associated article.

Download this summary

Child Body Mass Index Dropped After Healthy, Hunger-Free Kids Act in Schools

ECHO Researchers Investigate Whether Prenatal Chemical Exposures Affect the Development of Autism-related Traits in Children

Posted on January 26, 2023October 25, 2024 by Jodi Snare

Collaborative ECHO research led by Jennifer Ames, PhD of the Kaiser Permanente Northern California Division of Research and Ghassan Hamra, PhD of Johns Hopkins Bloomberg School of Public Health, investigates whether exposures to per- and polyfluoroalkyl substances (PFAS) during pregnancy were associated with the development of autism-related traits in children. The researchers looked at data from 1,224 mother-child pairs and found that prenatal exposure to one specific PFAS chemical, perfluorononanoic acid (PFNA), may be associated with an increase in autism-related traits in children. Prenatal exposure to the mixture of all PFAS chemicals combined was not associated with increased autism-related traits in children. This research, titled “Prenatal exposure to per- and polyfluoroalkyl substances and childhood autism-related outcomes,” is published in Epidemiology.

PFAS are widely used, long lasting chemicals, the components of which break down very slowly over time. Previous studies that have investigated the association between prenatal PFAS exposure and childhood autism spectrum disorder (ASD) have been inconsistent and mostly involved small sample sizes. This study leveraged the large, diverse ECHO-wide cohort to evaluate how prenatal PFAS exposure affects the development autism-related traits, even when a child does not receive a clinical ASD diagnosis.

This study included children born between 2011 and 2018 from 10 racially and ethnically diverse ECHO cohorts across the United States, including one cohort that enrolls children from families with an increased likelihood of ASD. The researchers measured the levels of eight different PFAS in blood samples collected from mothers during pregnancy. Later, when their children were aged 2.5 years or older, researchers asked caregivers to report on their child’s autism-related traits using a questionnaire called the Social Responsiveness Scale (SRS). The research team tracked the associations between these data to examine child SRS scores in relation to each individual PFAS as well as the combination of the PFAS.

“In the U.S. population, exposures to perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have dropped substantially since the industry voluntarily phased out these chemicals in the early 2000s,” said Dr. Ames. “However, other PFAS exposures have increased over time, including thousands with unknown toxicity. These so-called ‘forever chemicals’ continue to pose risks to health even after they are phased out because they persist in the environment and inside people’s bodies and don’t break down easily.”

These results underscore the need for more research on whether PFAS chemicals might have more significant effects on child neurodevelopment, and whether factors such as genetics, underlying health conditions, or nutritional status may change the effect of PFAS exposure on brain development.

Read the research summary.

ECHO Study Suggests Prenatal Exposure to Perfluorononanoic Acid (PFNA) May Be Linked to Autism-Related Traits in Children

<< Back to Research Summaries

ECHO Study Suggests Prenatal Exposure to Perfluorononanoic Acid (PFNA) May Be Linked to Autism-Related Traits in Children

Authors: Jennifer Ames, Ghassan Hamra, 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?

The researchers found that prenatal exposure to one specific PFAS chemical, perfluorononanoic acid (PFNA) may be associated with an increase in autism-related traits in children. Prenatal exposure to the mixture of all PFAS chemicals combined was not associated with increased autism-related traits in children.

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 draws attention to the potential risks of PFAS chemicals on child neurodevelopment. In the U.S., exposures to some specific PFAS, such as PFOA and PFOS, have dropped substantially since the industry voluntarily phased these chemicals out in the early 2000s. However, other PFAS exposures have increased over time, including thousands of these substances with unknown toxicity. These so-called “forever chemicals” continue to pose risks to health even after they are phased out because they persist in the environment and inside people’s bodies and don’t break down easily. While the estimated effects of PFAS chemicals on child autism-related traits are relatively small in this study, future studies may investigate whether early childhood exposure to PFAS chemicals are associated with effects on other neurodevelopmental outcomes.

Why was this study needed?

Per- and polyfluoroalkyl substances (PFAS) are widely used, long lasting chemicals, the components of which break down very slowly over time. Previous studies looking at associations between prenatal PFAS exposure and childhood autism spectrum disorder (ASD) are inconsistent and mostly conducted in small sample sizes. The objective of this research was to determine whether blood concentrations of PFAS during pregnancy were linked to the development of autism-related traits in children. The researchers in this study were able to examine this question by continuously measuring the development of autism-related traits in a large number of children across the U.S, independently of whether a child received a clinical ASD diagnosis.

Who was involved?

The participants of this study included 1,224 mother-child pairs from ten cohorts across the United States. The participants were geographically, racially, and ethnically diverse, and one of the cohorts included families with an increased genetic likelihood of ASD. Most of the participating children were born between 2011 and 2018.

What happened during the study?

The researchers measured the levels of eight different PFAS in blood samples collected from mothers during pregnancy. Later, when their children were aged 2.5 years or older, researchers asked caregivers to report on the child’s autism-related traits using a questionnaire called the Social Responsiveness Scale (SRS). The research team tracked the relationship between child SRS scores and prenatal exposure to each individual PFAS as well as the combination of the eight PFAS.

What happens next?

Additional research is needed to continue studying the effect of early life exposure to PFAS on child neurodevelopment, including cognition, attention, and other neurobehaviors. Future studies can also investigate whether biological sex and other factors—such as genetics, underlying health conditions, and nutritional status—may change the effect of PFAS exposure on brain development.

Where can I learn more?

Access the full journal article, titled “Prenatal exposure to per- and polyfluoroalkyl substances and childhood autism-related outcomes,” in Epidemiology.

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

Published January 12, 2023

Access the associated article.

See ECHO's PFAS research.

Download this summary

ECHO Study Suggests Prenatal Exposure to Perfluorononanoic Acid (PFNA) May Be Linked to Autism-Related Traits in Children

ECHO Study Suggests COVID-19 Pandemic Contributed to Developmental Delays in Infants, Toddlers

<< Back to Research Summaries

ECHO Study Suggests COVID-19 Pandemic Contributed to Developmental Delays in Infants, Toddlers

Authors: Sara Nozadi, Johnnye Lewis, 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.

What were the study results?

In this study, up to 15% of infants and toddlers who were developmentally on track prior to the COVID-19 pandemic showed signs of developmental delays during the pandemic. Male children showed more delays than female children, and language was the most affected developmental area. Families from minority communities and those with lower socioeconomic status were more likely to experience pandemic-related hardships. However, financial and social pandemic-related hardships were not associated with the individual changes observed in children’s developmental progress.

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 highlights the importance of early developmental screening during times of adversity, such as pandemics, in order to identify delays and connect children to supportive services. Previous studies have shown negative impacts of the pandemic on overall child development but have not looked at the effects of the pandemic on individual children’s development over time.

Why was this study needed?

Many studies have focused on the COVID-19 pandemic’s effects on the development of school-aged children, evaluating the effects of the pandemic on academic performance and behavior problems. Fewer studies have examined the pandemic’s effects on the developmental progress of infants and toddlers, whose needs are different than those of school-aged children. During this study, researchers examined whether the negative developmental effects observed in school-aged children over the course of the pandemic could also be seen in infants and toddlers.

Who was involved?

The study included 684 children between the ages of 2 months and 4 years from 8 ECHO cohort research sites across the United States. Researchers included children whose parents had filled out the Ages and Stages Questionnaire (ASQ), which uses parent-reported information to pinpoint a child’s developmental progress, within the 18-month period before and after March 2020. Parents of participating children were also asked about financial hardship, defined as at least one parent experiencing job loss or change, or social hardships, defined as families’ quarantining from household members or extended family and friends, during the pandemic.

What happened during the study?

Parents answered 30 questions before and during the pandemic to determine whether their child had achieved developmental milestones in language, motor, cognitive or problem solving, and socioemotional development. Researchers also used the ECHO COVID-19 survey that was developed in April 2020 to gauge pandemic-related financial and social stress on families.

What happens next?

Future research can follow the developmental patterns in these children over time to determine if COVID-19 related delays are lasting or reversible. Studies may also focus on pandemic-related stressors that could particularly effect infants and toddlers, such as family dynamics, parent-child interactions and parental stress.

Where can I learn more?

Access the full journal article, titled “Effects of COVID-19 financial and social hardships on infants’ and toddlers’ development in the ECHO program,” in the International Journal of Environmental Research and Public Health.

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

Published January 5, 2023

Access the associated article.

Download this summary

ECHO Study Suggests COVID-19 Pandemic Contributed to Developmental Delays in Infants, Toddlers

ECHO Study Finds Associations Between Neighborhood Social Vulnerability at Birth With Higher Childhood Body Mass Index

<< Back to Research Summaries

ECHO Study Finds Associations Between Neighborhood Social Vulnerability at Birth With Higher Childhood Body Mass Index

Author(s): Izzuddin M. Aris, 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.

What were the study results?

The study found that children who lived in higher opportunity or less vulnerable neighborhoods early in life had lower average BMI and lower risk of obesity from childhood to adolescence. The neighborhoods children lived in at birth affected these health outcomes more than the neighborhoods they lived in later in childhood. These associations were not affected by individual and family sociodemographics or by prenatal risk factors for childhood obesity.

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 research focuses on how community resources can enhance children’s health outcomes. The Child Opportunity Index, Social Vulnerability Index, and other measures of neighborhood characteristics could help inform efforts to reduce neighborhood barriers and improve access to community resources so families can better support their children’s health and well-being.

Why was this study needed?

The physical and social characteristics of neighborhoods may influence how children grow and develop. Children’s body mass index (BMI)—an estimation of their overall body fat—and childhood obesity are significant risk factors for heart disease later in life. The associations between neighborhood characteristics and children’s BMI and risk of obesity remains understudied. This study compared neighborhood-level measures of opportunity and social vulnerability with BMI and obesity patterns in children from birth to adolescence.

Who was involved?

This study included 20,677 children from 54 ECHO cohorts located across the United States.

What happened during the study?

ECHO researchers collected each child’s home address and weight at birth, infancy (6 months‒1.5 years), early childhood (2‒5 years), and mid-childhood (5‒10 years). The researchers linked participants’ addresses throughout childhood to data from the Child Opportunity Index and Social Vulnerability Index. The Child Opportunity Index measures neighborhood conditions and resources that may affect child health outcomes including education, health and environment, and social and economic factors. The Social Vulnerability Index identifies communities with high numbers of public health emergencies and other stressors by looking at demographics, socioeconomic status, type of housing, access to transportation, and other factors.

The researchers used these data to examine links between children’s neighborhood-level opportunity and social vulnerability and their BMI and obesity over time.

What happens next?

More research is needed to determine how changes to specific aspects of neighborhood environments might influence weight gain and obesity in children.

Where can I learn more?

Access the full journal article, titled “Associations of Neighborhood Opportunity and Vulnerability with Trajectories of Child Body Mass Index and Obesity Among U.S. 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: December 22, 2022

Access the associated article.

Download this summary

ECHO Study Finds Associations Between Neighborhood Social Vulnerability at Birth With Higher Childhood Body Mass Index

ECHO Study Suggests Link Between Severe Bronchiolitis During Infancy and Asthma During Childhood

<< Back to Research Summaries

ECHO Study Suggests Link Between Severe Bronchiolitis During Infancy and Asthma During Childhood

Author(s): Kohei Hasegawa, 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.

What were the study results?

Bronchiolitis is a wheezing illness usually caused by a lung infection such as Respiratory Syncytial Virus (RSV). During this study, researchers found that the hospitalized infants with bronchiolitis were more likely to develop asthma by the age of 12 years when compared to hospitalized infant without bronchiolitis. The researchers also saw that this effect was stronger for non-Hispanic White and non-Hispanic Black infants, compared with Hispanic infants.

What was the study's impact?

This is the first nationwide investigation that demonstrates the role of severe bronchiolitis during infancy on influencing long-term childhood asthma risk and identifies subgroups of children who are most at risk for developing asthma following bronchiolitis during infancy. These results could help future investigations to identify what factors may influence the association between severe bronchiolitis and childhood asthma risk across different demographic groups, which could advance the development of targeted prevention strategies for childhood asthma.

Why was this study needed?

Severe bronchiolitis is the most common reason for hospitalization in U.S. infants younger than 2 years old. Many studies have shown that severe bronchiolitis, requiring hospitalization during infancy, is a risk factor for developing childhood asthma. However, these studies have been too narrow to evaluate how severe bronchiolitis during infancy affects childhood asthma risk in various demographic subgroups.

Who was involved?

The researchers analyzed data from 11,762 infants enrolled in 53 ECHO research sites across the United States. All of these infants were hospitalized at age 12 months or younger between 2001-2021. Of these infants, 10% were hospitalized with bronchiolitis. One of the participating ECHO cohorts selectively enrolled children with a parental history of asthma.

What happened during the study?

The researchers collected data from participating infants under 12 months old on caregiver-reported hospitalization for bronchiolitis. The researchers then used data on caregiver-reported asthma diagnosis prior to age 12 to evaluate the relationship between severe bronchiolitis and childhood asthma to determine how this relationship may be affected by major demographic and clinical factors.

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 are needed to investigate the reasons underlying the links among infant bronchiolitis, demographic and clinical factors, and the development of asthma. These findings not only provide an evidence base for early identification of children who are at high risk for asthma but also offer opportunities for early preventive interventions in this large, high-risk population.

Where can I learn more?

Access the full journal article, titled “Association of Severe Bronchiolitis during Infancy with Childhood Asthma Development: An Analysis of the ECHO Consortium,” in Biomedicines.

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

Published: December 22, 2022

Download this summary

ECHO Study Suggests Link Between Severe Bronchiolitis During Infancy and Asthma During Childhood

Mothers Who Experience More Life Changes Due to the COVID-19 Pandemic Reported More Symptoms of Traumatic Stress

<< Back to Research Summaries

Mothers Who Experience More Life Changes Due to the COVID-19 Pandemic Reported More Symptoms of Traumatic Stress

Authors: Tracy Bastain, Amy Margolis, 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.

What were the study results?

The study identified two groups of mothers based on their pandemic experiences. One of these groups experienced more changes to their daily life routines, more isolation from friends and family, and more changes to their health behaviors, when compared to the other group who experienced fewer pandemic-related changes in their lives.

Mothers who reported more life changes also reported more symptoms of traumatic stress due to the pandemic. The mothers who fell into the group that experienced more changes and reported more symptoms of traumatic stress tended to be women with higher incomes and higher education. Sixty-six percent of the women in the high change group were white. The women in the high change group were more likely to report financial concerns as a cause of stress. They were also more likely to report that the pandemic affected their healthcare.

In contrast, the group that reported fewer changes tended to have lower education and lower income. The women in this group were primarily Black and Native American. Hispanic women were split evenly between the two groups.

Both groups reported similar rates of COVID-19 infection in the household and similar work changes.

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.

Impact

As compared to fathers, during the COVID-19 pandemic more mothers have been affected by job and income losses, taken on more childcare burdens related to remote schooling, and have made major adjustments to their daily routines. This study found that mothers who had the most changes to their work, health, and social support systems also reported the highest amounts of traumatic stress due to the pandemic. These findings suggest that the association between sociodemographic, stressful life events, and mental health should be considered in future studies examining the long-term outcomes of the COVID-19 pandemic.

Why was this study needed?

The goal of this study was to better understand the mental health impacts of the COVID-19 pandemic on mothers in the United States and Puerto Rico.

Who was involved?

This study included 11,473 mothers from 62 ECHO cohorts across the U.S. and Puerto Rico.

What happened during the study?

ECHO researchers investigated the potential impacts of the COVID-19 pandemic on maternal mental health, from April 2020 through August 2021. The researchers looked for patterns of pandemic-related changes in maternal health and health behaviors, healthcare visits, work and finances, and coping strategies. They then used these data to group the mothers by those who had more or fewer pandemic-related changes to examine whether these groups reported higher or lower symptoms of traumatic stress related to the pandemic.

What happens next?

Future studies could examine how changes over the course of the pandemic affect mothers’ stress and well-being.

Where can I learn more?

Access the full journal article, titled “COVID-19 Pandemic Experiences and Symptoms of Pandemic-Associated Traumatic Stress Among Mothers in the US,” 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 December 16, 2022

Access the associated article.

Download this summary

Mothers Who Experience More Life Changes Due to the COVID-19 Pandemic Reported More Symptoms of Traumatic Stress

No Association Between Antidepressant Use During Pregnancy, Child’s Risk for Autism-Related Traits

<< Back to Research Summaries

No Association Between Antidepressant Use During Pregnancy, Child's Risk for Autism-Related Traits

Authors: Patricia Brennan, 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?

This study found that prenatal use of antidepressants, including selective serotonin reuptake inhibitors (SSRIs), did not increase a child’s risk for ASD or related traits.

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?

Pregnant women who are diagnosed with depression must weigh a number of risks when making decisions about treatments. Sometimes medical providers may recommend treatment with antidepressants. This study suggests that maternal use of antidepressants, including SSRIs, during pregnancy does not increase a child’s risk for autism-related traits. This information can be valuable in helping pregnant women and their physicians decide whether antidepressant treatment is right for them.

Why was this study needed?

Previous studies have reported mixed findings on the relationship between prenatal antidepressant use and child autism. Pregnant women and the physicians that treat them need more data to inform their decisions about whether to take certain medications during pregnancy.

Who was involved?

This study included 3,129 mothers and their children enrolled in ECHO cohorts across the United States. Participants provided data on prenatal exposure to antidepressants as well as measures of autism-related traits collected when the child was between 1 and 12 years of age. About 5% of the participating mothers took antidepressants during pregnancy.

What happened during the study?

The researchers used medical records and maternal self-reports to determine what medicines mothers used during pregnancy. Mothers reported on whether their child received an autism spectrum disorder (ASD) diagnosis and also completed rating scales about their child’s behavior, including social, language, and other traits related to autism.

What happens next?

Future studies might consider whether the dose or timing of antidepressant use during pregnancy changes its effect on child health outcomes.

Where can I learn more?

Access the full journal article, titled “Prenatal Antidepressant Exposures and Autism Spectrum Disorder or Traits: A Retrospective, Multi-Cohort Study,” in Research on Child and Adolescent Psychopathology.

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

Published November 22, 2022

Access the associated article.

Download this summary

No Association Between Antidepressant Use During Pregnancy, Child's Risk for Autism-Related Traits

ECHO Study Suggests Eating Processed Foods May Affect How Long Mothers Breastfeed Their Babies

<< Back to Research Summaries

ECHO Study Suggests Eating Processed Foods May Affect How Long Mothers Breastfeed Their Babies

Authors: Emily Zimmerman, 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?

The results from this study suggested that pregnant women who reported eating the most processed food and take-out tended to breastfeed for an average of 16 weeks (4 months), while pregnant women who reported eating the least amount of processed food and take-out breastfed for an average of 41 weeks (10 months).

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 large and diverse cohort study examining the potential link between maternal food quality during pregnancy and breastfeeding duration. The results from this study suggest that pregnant women who eat a lot of processed food or take-out during pregnancy, tend to breastfeed for a shorter period of time.

Why was this study needed?

Breastfeeding promotes positive health outcomes for infants, but few studies have looked at the connection between the quality of mothers’ food during pregnancy and the length of time they breastfed. This study examined the relationship between self-reported food quality and preparation (e.g., organic foods, processed foods, take out) during pregnancy and breastfeeding duration.

Who was involved?

This study included 751 mothers who were at least 18 years old and their infants from 12 ECHO cohorts located across the United States.

What happened during the study?

Mothers reported on their food source and preparation during pregnancy and were placed in one of three groups: high, moderate, or low food source quality. Mothers also reported on their breastfeeding duration. Researchers investigated whether there was a relationship between the mothers’ food quality during pregnancy and the length of time they breastfed.

What happens next?

Future studies are needed to understand the relation between breastfeeding duration and maternal food quality over time. These studies can also provide more specific information on maternal diet, food source, and preparation during pregnancy while considering other important factors, like socioeconomic status, that may affect the types of foods mothers have access too.

Where can I learn more?

Access the full journal article, titled “Association Between Quality of Maternal Prenatal Food Source and Preparation and Breastfeeding Duration in The Environmental influences on Child Health Outcome (ECHO) Program,” in Nutrients.

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

Published November 21, 2022

Access the associated article.

Download this summary

ECHO Study Suggests Eating Processed Foods May Affect How Long Mothers Breastfeed Their Babies

ECHO Study Suggests Oxidative Stress Contributes to Mother’s Risk for Preterm Birth

<< Back to Research Summaries

ECHO Study Suggests Oxidative Stress Contributes to Mother's Risk for Preterm Birth

Authors: Stephanie Eick, Rachel Morello-Frosch, et al.

Who sponsored this study?

Research reported in this publication was supported by the Environmental influences on Child Health Outcomes (ECHO) Program, Office of The Director, National Institutes of Health (NIH).

What were the study results?

Pregnant participants who had higher levels of oxidative stress biomarkers during pregnancy were more likely to deliver preterm babies. This association was stronger for participants who experienced preterm birth that was sudden and unexpected or occurred prior to 34 weeks.

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 is the largest to date to look at the relationship between oxidative stress and preterm birth.

The study included a large group of racially, ethnically, and demographically diverse pregnant participants from across the mainland United States and Puerto Rico. The results from this study support prior findings that oxidative stress is higher among pregnant women who deliver preterm. The methods used in this study may help doctors identify pregnant women who may be at risk for preterm birth and plan targeted interventions.

Why was this study needed?

Oxidative stress is a process that can trigger cell damage and can play a role in the development of some diseases. Previous research has shown that oxidative stress in pregnant women may be linked to preterm birth. However, prior studies on this topic have involved small, primarily White populations, which does not reflect the diversity in the United States.

Who was involved?

This study involved 1,916 pregnant participants in the United States and Puerto Rico who were enrolled in one of four ECHO cohorts.

What happened during the study?

The researchers measured the levels of oxidative stress biomarkers from urine samples collected from participants during the second and third trimesters of pregnancy. They used these measurements to determine whether levels of oxidative stress were higher among participants who delivered their babies before 37 weeks (preterm birth).

What happens next?

Next, the researchers will study how exposure to environmental chemicals may lead to an increase in oxidative stress, ultimately leading to preterm birth. Future research will also identify what risk factors lead to higher oxidative stress during pregnancy.

Where can I learn more?

Access the full journal article, titled “A pooled analysis of four birth cohorts examining urinary oxidative stress biomarkers and preterm birth” in the American Journal of Obstetrics and Gynecology.

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

Published November 15, 2022

Access the associated article.

Download this summary

ECHO Study Suggests Oxidative Stress Contributes to Mother's Risk for Preterm Birth