Air pollution can reshape a baby’s brain before birth

Growing fetuses are more vulnerable than we think. A new study reveals how air pollution may subtly reshape brain structures before birth.

The research was conducted by experts at the Barcelona Institute for Global Health (ISGlobal) and was supported by the ”la Caixa” Foundation. The study is the first to assess fetal brain changes in relation to air pollution during pregnancy.

The researchers analyzed 754 mother-fetus pairs from the BiSC (Barcelona Life Study Cohort). The BISC project focused on brain development patterns and used high-resolution ultrasound imaging to identify early changes.

Air pollution exposure in pregnant women

The researchers used transvaginal neurosonography in the third trimester. This technique offered a detailed view of fetal brain structures.

The team estimated exposure to nitrogen dioxide (NO₂), PM2.5, and black carbon using hybrid models. The models blended real-time environmental readings with statistical methods.

The researchers also tracked the microenvironments that were frequented by the pregnant participants. Homes, workplaces, and commuting routes were all considered.

A geolocation app on mobile phones helped map daily movement and link it to pollution exposure.

Changes detected in brain due to pollution

The study revealed that fetuses exposed to higher levels of pollutants showed notable changes in brain structure. These included enlarged lateral ventricles and cisterna magna. Both are cavities filled with cerebrospinal fluid.

The cerebellar vermis, which supports balance and coordination, also appeared wider after pollution exposure.

Interestingly, black carbon exposure was associated with a shallower lateral sulcus. This groove in the brain is important for normal development. Shallower sulci may signal less mature cortical folding.

Critical development and air quality

The second and third trimesters are critical for brain formation. “During mid to late gestation, the fetal brain enters a key phase of its development, making it particularly vulnerable to external factors such as pollution,” explained Payam Dadvand, ISGlobal researcher and senior author.

These alterations were consistent across different types of pollutants. The effects were most evident when exposure occurred in later pregnancy.

“The associations we found were consistent for NO₂, PM2.5, and black carbon,” wrote the study authors. This strengthens the link between common urban pollutants and fetal brain development.

Healthcare awareness must evolve

Study co-authors Elisa Llurba and Lola Gómez-Roig are clinicians at BCNatal. They noted that – even in pregnancies that appear healthy by all conventional measures – factors such as air pollution can subtly affect fetal brain development.

“These findings underline the importance of increased awareness and education, both within the health community and across society.”

The experts stress that traditional health metrics might miss these emerging risks. Early detection tools and preventative strategies must adapt to environmental realities.

Brain changes from pollution

Although all of the measurements remained within the normal range, the researchers emphasize the broader implications of the findings.

“The point is that these differences, although small at the individual level, are indeed relevant from a population perspective, as they inform us about how pollution affects the fetal brain and its vulnerability to environmental exposures,” said Laura Gómez-Herrera, co-lead author of the study.

These variations might not cause immediate medical concerns. But they offer insight into long-term neurodevelopment patterns that deserve attention.

Future research and health policies

The study concludes that more research is necessary to understand the long-term consequences.

“At this stage, we can only report having observed differences in the brains of fetuses with higher exposure to pollution compared to those with lower exposure,” noted Jordi Sunyer, senior author of the study.

“Additional research is needed to determine whether these effects are reversible after birth or if they persist, and whether they have any implications for neurodevelopmental outcomes in later stages.”

According to Yu Zhao, co-lead author and ISGlobal researcher, the findings strengthen the evidence supporting the need to reduce pregnant women’s exposure to air pollution, particularly in urban settings.

Pregnant women might not have control over city air, but this research calls on society to take responsibility. Clean air is not just a health issue. It’s part of giving every child a safer start.

The study is published in the journal The Lancet Planetary Health.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–