SALT LAKE CITY — Researchers say a new University of Utah Health study exploring how air quality intersects with miscarriage has yielded "upsetting" results indicating women are at greater risk of losing their pregnancy within days of a spike in nitrogen dioxide pollution along the Wasatch Front.
U. researchers used data from more than 1,300 Utah women who visited the University of Utah Hospital's emergency room due to a miscarriage between 2007 and 2015. They also examined seven-day windows in which there were measurements showing elevated levels of three common air pollutants: nitrogen dioxide, ozone and small particulate matter.
University of Utah researchers' analysis of the data found that, during the seven-day window following a spike in the amount of nitrogen dioxide in the air along the Wasatch Front, leaving "women exposed to elevated levels," there was a 16 percent increase in their risk of miscarriage.
“The results of this study are upsetting, and we need to work together as a society to find constructive solutions,” said Dr. Matthew Fuller, the study's senior author and assistant professor of surgery at University of Utah Health, in a prepared statement.
The study was published this month in the peer-reviewed journal Fertility and Sterility, a publication produced by the American Society for Reproductive Medicine. A summary of its findings says researchers found that spikes in particulate matter levels "were associated with increased risk of spontaneous pregnancy loss," but unlike with nitrogen dioxide, such a correlation "did not reach statistical significance."
The study adds in its conclusion that "we found no evidence of increased risk" associated with ozone levels.
Fuller and his fellow researchers made efforts to control for other potential interfering variables, including the mother's age, U. Health science writer Stacy Kish explained in a release. Miscarriages occurring in gestational stages up to 20 weeks were counted.
"Fuller recommends women speak with their doctor about any health concerns," Kish wrote. "Women can manage the risk by using a N95 particulate respirator face mask to filter out pollutants or avoid outdoor physical activity on poor air quality days. Women can also use filters to lower indoor pollution and, if possible, time conception to avoid seasonal episodes of poor air quality."
Kish explained that the Wasatch Front sees spikes in short intervals of bad air quality "primarily during the winter months, when inversions trap pollutants close to the ground."
Prior studies have also linked poor air quality to health issues such as pre-term birth, asthma and increased risk for a heart attack. Fuller said the new findings addressing pregnancy loss have implications for Utah families specifically, but also for everyone concerned with air quality's effects on their health.
“While we live in a pretty unique geographic area, the problems we face when it comes to air pollution are not unique,” he said. “As the planet warms and population booms, air pollution is going to become a bigger problem not only in the developing world but across the United States.”
U. research analyst Claire Leiser, listed as first author of the study, cautioned that there are limitations to the study, as its data is pulled exclusively from women who received care after their miscarriage at a single emergency department, thus not including Utah women who got help elsewhere such as through a primary care doctor or obstetrician.
“We are really only seeing the most severe cases during a small window of time,” Leiser said in a statement. “These results are not the whole picture.”
The study was also limited in that it was "unable to pinpoint a critical period" in early gestation "when the fetus may be most vulnerable to pollutants," according to Kish.
Researchers from Hurley Medical Center in Flint, Michigan, and Oregon Health and Science University in Portland also contributed to the study. It was funded with grants from the National Institutes of Health and the Consortium for Families & Health Research.
Correction: An earlier version mistakenly referred to nitrogen oxide as a pollutant researched as part of University of Utah Health's newly published study. It was nitrogen dioxide, not nitrogen oxide, that was studied.