Exposure to airborne particulate matter during pregnancy is associated with preterm birth: a population-based cohort study ( 8 page pdf, Emily DeFranco, William Moravec, Fan Xu, Eric Hall, Monir Hossain, Erin N. Haynes, Louis Muglia and Aimin Chen, Environmental Health, Jan. 15 2016)
Also discussed here: Exposure to high levels of air pollution associated with higher risk of preterm birth (ScienceDaily. Jan. 26, 206)
Today we review research into the link between preterm births and exposure during pregnancy to Particuate Matter (PM2.5) in an urban environment. Results indicate a 19% overall increased risk with the greatest risk during the 3rd trimester of pregnancy (prior to the 37th week) Dropping PM2.5 levels to below the EPA standard of 15μg/m3 could result in a 17% improvement in the frequency of preterm births.
“The study… identified a 19 percent increased risk, with the greatest risk when high exposure occurred during the third trimester of pregnancy.”
"Although the risk increase is modest, the potential impact is robust, as all pregnant women are potentially at risk,"
"We estimate that decreasing the amount of particulate matter in the air below the EPA's standard threshold could decrease preterm birth in women exposed to high levels of small particulates by about 17 percent, which corresponds to a 2.22 percent decrease in the preterm birth rate in the population as a whole."
“Preterm birth rates were higher among mothers exposed to high levels of airborne particle pollution above the EPA standard, as well as among mothers 40 or older, black mothers, and women with no prenatal care or with lower education level.”