blood pressure

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

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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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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

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

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Prenatal and Early-Life Pollution Exposures May Influence Childhood Blood Pressure Patterns, ECHO Study Finds

Posted on by Jodi Snare

A child’s blood pressure may be influenced by exposure to air pollution before and shortly after birth, according to a new study from the NIH-funded Environmental influences on Child Health Outcomes (ECHO) Program. The study focused on fine particulate matter (PM2.5) and nitrogen dioxide (NO2), common pollutants from vehicles, power plants, and other industrial sources.

High blood pressure in children is becoming more common worldwide and can lead to long-term health problems, including heart disease and impaired kidney function. Over the past two decades, childhood hypertension has increased by nearly 80 percent, particularly in countries with higher obesity rates, such as the United States. Because the roots of adult hypertension often begin in childhood, ECHO researchers examined whether early exposure to outdoor air pollution may influence blood pressure in children.

Air pollutants such as PM2.5 and NO2 are known contributors to cardiovascular disease in adults, but their effects on children’s blood pressure are less well understood. Previous studies have produced mixed results and were often limited to single locations. This ECHO study leveraged data from multiple cohort sites across the United States to better clarify these associations.

Researchers analyzed data from 4,863 children ages 5 to 12 from 20 ECHO Cohort Study Sites. They estimated outdoor air pollution exposure at participants’ home addresses during each trimester of pregnancy, across the full pregnancy, and during the child’s first two years of life. Children’s blood pressure was measured during study visits and compared with typical values for children of the same age, sex, and height. Blood pressure was considered high if it fell within the top 10 percent of these values.

Key Findings

  • PM2.5 exposure and higher blood pressure: Children who were exposed to higher levels of PM2.5 before and after birth had higher blood pressure on average between ages 5 and 12.
  • Early pregnancy as a sensitive period: Higher PM2.5 exposure during the first trimester was associated with a more pronounced systolic blood pressure and a greater likelihood of high blood pressure in childhood, indicating that early pregnancy may be a particularly sensitive period.
  • Unexpected findings for NO2: Higher maternal exposure to NO2 during pregnancy was associated with slightly lower blood pressure in children. This association was strongest during mid- to late pregnancy, particularly the second trimester, and was not linked to an increased risk of high blood pressure.
  • Timing matters: The results suggest that the timing of pollution exposure during pregnancy may be important for understanding its impact on children’s cardiovascular health.

“These findings add to growing evidence that early-life exposure to fine particulate air pollution may affect children’s cardiometabolic health, even at relatively low levels,” said study author Yu Ni, PhD, of San Diego State University. “The unexpected findings related to nitrogen dioxide suggest that more research is needed to understand how this type of air pollution may affect children’s developing bodies, as well as whether other environmental factors could be playing a role, such as transportation noise.”

This collaborative research was published in Environmental Research.

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.

Higher Early-Life PM2.5 Linked to Higher Childhood Blood Pressure, While Prenatal NO2 Exposure Associated with Lower Blood Pressure, ECHO Study Finds

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Higher Early-Life PM2.5 Linked to Higher Childhood Blood Pressure, While Prenatal NO2 Exposure Associated with Lower Blood Pressure, ECHO Study Finds

Authors: Yu Ni, Catherine Karr, 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?

The prevalence of high blood pressure (HBP) in children is rising globally, with long-term health consequences such as heart disease and impaired kidney function. Childhood high blood pressure has increased by nearly 80% over the past two decades, especially in countries with higher obesity rates like the United States. Since high blood pressure in childhood can both track into adulthood and affect children’s health directly, ECHO researchers wanted to understand the influence that environmental factors such as pollution can have on childhood blood pressure. Specific pollutants such as fine particulate matter (PM2.5) and nitrogen dioxide (NO2) are emitted from vehicles, power plants, and industrial processes. These pollutants are known contributors to heart disease in adults, but their impact on children’s blood pressure is less clear. Previous research has been inconclusive, often limited to single-site studies. Researchers used the ECHO Cohort’s large, multi-site study structure to help clarify these associations.

 

What were the study results?

Children who were exposed to more PM2.5 air pollution before and after birth had slightly higher blood pressure on average between ages 5 and 12. Specifically, higher PM2.5 exposure during the first trimester was linked to a more pronounced increase in systolic blood pressure and a greater risk of high blood pressure in childhood, indicating that early pregnancy may be a particularly sensitive period. When their mothers were exposed to more NO2 air pollution during pregnancy, children unexpectedly had lower blood pressure. The study found that NO2 exposure during mid- to late pregnancy was associated with slightly lower blood pressure levels, particularly in the second trimester, and was not linked to a higher risk of high blood pressure. These findings overall suggest that timing of pollution exposure during pregnancy matters for children’s blood pressure later in life.

 

What was this study's impact?

The study provides additional evidence that exposure to PM2.5 may be associated with adverse effects on childhood cardiometabolic health, even at low exposure levels. The observed association between prenatal NO2 exposure and decreased childhood blood pressure is unexpected and suggests that further research may be needed to better understand the underlying mechanisms as well as other environmental factors that may influence this relationship.

 

Who was involved?

The study included 4,863 U.S. children aged 5–12 years and their mothers, drawn from 20 ECHO Cohort Study Sites.

 

What happened during the study?

Researchers estimated how much outdoor air pollution children were exposed to at their homes, focusing on PM2.5 and NO2. They examined exposure during each trimester of pregnancy, across the full pregnancy, and during the child’s first two years of life. Children’s blood pressure was measured between ages 5 and 12 and compared with typical levels for children of the same age, sex, and height; blood pressure was considered high if it fell within the top 10 percent of the distribution.

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

 

What happens next?

More research could help investigators better understand why exposure to nitrogen dioxide during pregnancy was linked to lower, rather than higher, blood pressure in children. This could include exploring possible biological explanations and looking at whether other environmental exposures that occur alongside air pollution may be influencing this finding, such as transportation noise exposure.

 

Where can I learn more?

Access the full journal article, titled “Pre- and Postnatal Exposure to PM2.5 and NO2 and Blood Pressure in Children: Results from the ECHO Cohort,” 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 December 23, 2025

Read the associated article.

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Higher Early-Life PM2.5 Linked to Higher Childhood Blood Pressure, While Prenatal NO2 Exposure Associated with Lower Blood Pressure, ECHO Study Finds

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