From The New York Times Blog "Well"
By Nicholas Bakalar
March 9, 2016
A new study suggests that women with asthma exposed to air pollution, even before conception, significantly increase their risk of delivering a premature baby.
Researchers studied 223,502 pregnancies among 204,175 women in 19 hospitals across the United States, gathering data on air quality in each region.
The study, in the Journal of Allergy and Clinical Immunology, found that all women with asthma were more likely than those without to deliver preterm. But there were significant increases in preterm birth in asthmatic women exposed to air pollution, including traffic-related pollutants.
Air pollution also appeared to take a toll even before conception. Asthmatic women exposed to pollutants in the three months before conception were at a 28 percent higher risk for preterm birth than women without asthma exposed at the same time in the same conditions.
“That’s a window that hasn’t been studied before,” said the lead author, Pauline Mendola, an epidemiologist with the National Institutes of Health. “We saw the increase for both groups, but it was much higher for women with asthma.”
Air pollution may be unavoidable, but Dr. Mendola said that pregnant women should avoid outdoor activity when pollution levels rise.
The Environmental Protection Agency “issues air pollution advisories when conditions are bad,” she said. ”They’re not specifically for pregnant women, but pregnant women with asthma should be particularly aware of them.”