When a woman is exposed to high levels of air pollution in the week before she gives birth, the baby is more likely to be admitted to a newborn intensive care unit (NICU). The type of pollution determines the increase in admissions, which ranges from 4% to 147%. These figures are in contrast to women who do not encounter high levels of air pollution at all.
The team of National Institutes for Health researchers that did the study that led to these findings was led by Pauline Mendola, Ph.D., of the Epidemiology Branch at NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development. She commented, “Short-term exposure to most types of air pollutants may increase the risk for NICU admission. If our findings are confirmed, they suggest that pregnant women may want to consider limiting their time outdoors when air quality advisories indicate unhealthy conditions.” The researchers reviewed data from the Consortium on Safe Labor, which has information on 223,000 births.
Among the air pollutants considered as causes for higher admissions to intensive care were emissions from diesel/gasoline engines, power plants, landfills and sewage facilities, as well as the byproducts of industrial processes. Of particular concern, “Exposure to high concentrations of organic compounds in the air was associated with a 147% increase in risk of NICU admission.”
The researchers said they did not know for certain what the relationship between air pollution and NICU admissions was. Their theory is that the inflammation air pollution can cause may partially cut blood supply from the placenta to the fetus.
The research comes at a time when scientists say air pollution is increasing, and 141 million Americans live in counties with unhealthy levels of ozone pollution. This is a particular problem in the 25 most polluted cities in the United States.