Recent research has revealed alarming connections between maternal exposure to air pollution during pregnancy and serious health consequences for newborns, including increased intensive care admissions and long-term neurological impacts.
Air Pollution Exposure Increases NICU Admission Risk
A study published in Scientific Reports demonstrates that exposure to air pollutants during the final month of pregnancy significantly increases a newborn's likelihood of requiring neonatal intensive care unit (NICU) treatment.
The research, led by Yohane Phiri, a postdoctoral research associate at the University at Buffalo's Department of Epidemiology and Environmental Health, found that maternal exposure to nitrogen dioxide—a gas produced by fossil fuel combustion in vehicles and power plants—increased NICU admission risk by 30-35%. Similarly, exposure to fine particulate matter raised NICU admission risk by 11-22%.
"Our findings highlight the critical impact of air pollution during the final weeks of pregnancy, a time of heightened fetal vulnerability, and emphasize the significance of addressing air pollution exposure, even at lower levels," Phiri stated.
The research team compared 2018 birth data against satellite tracking of air pollution levels across the United States, building upon previous research linking air pollution to pregnancy complications including birth defects, preterm delivery, and altered fetal growth.
Regional variations were observed, with the Midwest and Mid-Atlantic showing the highest odds of NICU admission due to nitrogen dioxide exposure. Fine particulate matter risks persisted along the West Coast and in the Southeast, with seasonal variations showing summer bringing the highest overall risk.
Prenatal Ozone Exposure Linked to Intellectual Disability
In a separate but equally concerning study published in the Journal of Exposure Science & Environmental Epidemiology, researchers from the University of Utah found that prenatal exposure to ozone pollution may harm fetal brain development, with lasting consequences.
The study revealed that a 10 parts-per-billion increase in ozone exposure during the second trimester of pregnancy was associated with a 55% increased risk of intellectual disability when comparing siblings with different exposure levels.
"Ozone exposure during pregnancy is a clear risk factor for intellectual disability," said lead researcher Sara Grineski, a professor of sociology at the University of Utah. "We were particularly struck by the consistency of the findings across all trimesters and the strength of the sibling-based analysis."
The research team analyzed data from the Utah Population Database, linking information on children with intellectual disabilities born between 2003 and 2013 to county-level daily estimates of ozone exposure from the U.S. Environmental Protection Agency.
The second trimester showed the strongest associations, a period when the fetal brain undergoes rapid growth with neurons developing at a rate of 250,000 per minute. The federal health standard for ozone exposure is currently 70 parts per billion.
Implications for Public Health Policy
Both studies underscore the urgent need for stricter air quality regulations and pollution reduction strategies, particularly in areas with high pollution levels.
"Salt Lake City ranks 10th for the most polluted cities in the U.S. in terms of ozone, and 2023 ozone levels were higher than 2022 levels," Grineski noted, highlighting the growing concern in many urban areas.
Researchers suggest that reducing ozone and other pollutant levels through clean car standards, transitioning to electric vehicles, and improving manufacturing and agricultural processes will be critical to protecting maternal and child health.
"While our findings are not causal, limiting direct inference, they support local and national initiatives aimed at further reducing air pollution and improving air quality," Phiri emphasized. "Such efforts could ultimately benefit pregnant women by minimizing exposure to harmful pollutants and reducing associated neonatal health risks."
The evidence continues to mount that air pollution exposure during pregnancy represents a significant and modifiable risk factor for both immediate neonatal outcomes and long-term neurodevelopmental health, making pollution reduction an essential public health priority.
