August 09, 2019
1 min read

Exposure to air pollution in utero may increase odds of NICU admission

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Photo of Pauline Mendola
Pauline Mendola

In utero exposure to common air pollutants appears to be associated with increased odds of NICU admission, according to study results published in Annals of Epidemiology.

Researchers said the findings suggest that air pollution is a “potentially modifiable risk factor” for NICU admission.

“This is the first study to really look at the association between short-term air pollution exposure and NICU admission,” Pauline Mendola, PhD, senior investigator in the Division of Intramural Population Health Research at the Eunice Kennedy Shriver National Institute of Child Health and Human Development in Rockville, Maryland, told Infectious Diseases in Children. “We find that fine particles and common traffic-related pollutants are associated with an increased risk, but those findings need further confirmation.”

If confirmed, Mendola said the findings suggest that ambient exposure to pollutants in the days before delivery might increase the need for intensive care in newborns.

For their study, Mendola and colleagues used an air quality model that relies on meteorological and emissions data to estimate the exposure to fine particulate matter (particles of 2.5 microns or less in width; PM2.5) in 27,189 singletons admitted to the NICU as part of the Consortium on Safe Labor, a retrospective cohort study conducted at 12 clinical sites in the United States. They compared exposure during the week of delivery to control periods before and after delivery.

According to the researchers, the models showed that exposure to PM2.5 constituents during the week before delivery was significantly associated with increased odds of NICU admission. Associations differed by constituent — elemental carbon increased the odds by 35%, ammonium ions 37%, nitrate compounds 16%, organic compounds 147% and sulfate compounds 35%.

The researchers also reported a significant increase in the likelihood of NICU admission if infants were exposed on the day of or day before delivery to carbon monoxide (4%-5%), nitrogen dioxide (13%), nitrogen oxides (4%-8%), PM10 (2%), PM2.5 (2%) and sulfur dioxide (3%-6%). They observed no associations related to the ozone.

“It's important for clinicians to be aware that the ambient environment in the days prior to delivery could be playing a role in babies needing extra care,” Mendola said. “The literature on air pollution in relation to adverse pregnancy outcomes continues to build.” – by Joe Gramigna

Disclosures: The authors report no relevant financial disclosures.