Maternal smoking during pregnancy has long been associated with adverse birth outcomes. A new research letter published in Circulation, Volume 153, Issue 7, dated February 17, 2026, adds to growing evidence that prenatal tobacco exposure may also influence cardiovascular health later in childhood.
The study, titled “Association of Maternal Smoking During Pregnancy With Childhood Blood Pressure and Hypertension in the ECHO Cohort,” examined how maternal tobacco smoking during pregnancy affects children’s blood pressure and risk of hypertension. Drawing on data from the large, nationwide Environmental Influences on Child Health Outcomes program, the findings suggest that children exposed to maternal smoking in utero may face a higher risk of elevated diastolic blood pressure and hypertension.
This article provides a detailed summary of the study, its methods, findings, and public health implications.
Elevated blood pressure during childhood is not a temporary concern. Research shows that children with high blood pressure are more likely to develop hypertension as adults. Adult hypertension is a major risk factor for cardiovascular disease, stroke, kidney disease, and premature death.
Understanding early life risk factors is essential for prevention. Prenatal exposures, including tobacco smoke, may program long-term cardiovascular changes that manifest years later.
Previous studies have linked maternal smoking during pregnancy to increased systolic blood pressure in children. However, earlier findings were inconsistent and often relied only on self-reported smoking data. Few studies examined both systolic and diastolic blood pressure or used biological markers to confirm exposure.
The new analysis from the ECHO cohort expands on earlier work with a large and diverse sample of US children.
The research letter was authored by Lyndsey E. Shorey Kendrick, PhD, and colleagues on behalf of the ECHO Cohort Consortium and published in Circulation in February 2026.
The investigators analyzed data from 13,120 children born between 1999 and 2020 across 52 cohorts in the United States. All children met the following criteria:
The prevalence of maternal smoking during pregnancy was 9.3 percent. The study population included:
The average age at blood pressure measurement was 6.17 years.
Researchers calculated standardized systolic and diastolic blood pressure Z scores adjusted for age, sex, and height. Hypertension was defined using established pediatric thresholds:
Among 4,158 children with measurements at three or more visits, 5.8 percent met criteria for hypertension.
To improve accuracy, a subset of 2,763 participants from 10 cohorts had maternal urine cotinine levels measured during pregnancy. Cotinine is a reliable biomarker of nicotine exposure.
Active smoking was defined as urine cotinine levels of at least 75 ng per mL. No exposure was defined as 1.6 ng per mL or lower.
Importantly, researchers observed more than 95 percent agreement between self-reported smoking and cotinine-based classification. This strengthens confidence in the exposure data.
Maternal smoking during pregnancy was significantly associated with higher diastolic blood pressure in children.
This indicates a measurable and statistically significant increase in diastolic blood pressure among exposed children.
The association between maternal smoking and systolic blood pressure was weaker and not statistically significant after adjustment.
This distinction is important because many previous studies focused primarily on systolic blood pressure.
Children exposed to maternal smoking during pregnancy had a 54 percent higher incidence rate of hypertension compared to unexposed children.
This finding suggests that prenatal tobacco exposure may meaningfully increase the likelihood of developing clinically significant hypertension during childhood.
The study explored whether associations differed by sex.
Results indicated stronger effects among girls compared with boys:
Although both sexes were affected, these findings raise the possibility that prenatal tobacco exposure may have sex specific cardiovascular effects.
When researchers stratified results by age, they observed that the effect on diastolic blood pressure was weaker in children younger than six years and stronger in those aged six years or older.
This pattern suggests that the cardiovascular impact of prenatal tobacco exposure may become more pronounced as children grow older.
The study also examined secondhand smoke exposure during pregnancy when someone other than the mother smoked in the home.
Unlike active maternal smoking, secondhand exposure during pregnancy was not associated with increased blood pressure Z scores in this analysis.
This research provides several strengths that enhance its credibility:
By leveraging data from the nationwide Environmental Influences on Child Health Outcomes consortium, the researchers were able to examine associations across multiple cohorts.
The findings reinforce that maternal smoking during pregnancy may have lasting cardiovascular consequences for offspring.
If prenatal tobacco exposure contributes to elevated childhood blood pressure and hypertension, reducing smoking during pregnancy could:
Given that childhood hypertension often tracks into adulthood, prevention efforts during pregnancy may have multigenerational benefits.
Public health strategies should continue to prioritize smoking cessation programs for women of reproductive age and pregnant individuals. Healthcare providers can play a crucial role by offering counseling, support, and evidence-based interventions.
As with any observational study, the findings do not prove causation. Although researchers adjusted for multiple confounding variables, residual confounding may still exist.
Additionally:
Despite these limitations, the consistency of findings and biomarker validation strengthen the overall conclusions.
The research letter published in Circulation provides compelling evidence that maternal smoking during pregnancy is associated with higher diastolic blood pressure and increased risk of hypertension in children.
Using data from more than 13,000 participants in the Environmental Influences on Child Health Outcomes cohort, investigators demonstrated that prenatal tobacco exposure may influence cardiovascular health well beyond birth.
These findings add urgency to efforts aimed at preventing smoking during pregnancy. Reducing maternal tobacco use may represent a critical strategy in lowering childhood and adult hypertension rates and improving long term cardiovascular outcomes.
Shorey Kendrick LE, Ladd Acosta C, Zhao H, et al. Association of Maternal Smoking During Pregnancy With Childhood Blood Pressure and Hypertension in the ECHO Cohort. Circulation. 2026;153(7):536 to 539. doi:10.1161/CIRCULATIONAHA.125.076520. Published in Circulation, Volume 153, Issue 7, February 17, 2026.
This blog post is intended for informational and educational purposes only. It summarizes findings from a published research letter and does not constitute medical advice. Individuals should consult qualified healthcare professionals for personalized medical guidance regarding smoking cessation, pregnancy care, blood pressure management, or cardiovascular health.
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