A new University of Utah study shows a link between air pollution and miscarriage, adding to a body of research implicating bad air in a number of pregnancy risks.

But the findings are not filtering into Utah doctors’ offices, according to several obstetricians and patients who told The Salt Lake Tribune that air pollution is not typically discussed in prenatal visits, despite frequently unsafe pollution levels along the Wasatch Front.

“I don’t think it's coming up reliably at all,” said Rebecca Ponder, an OB/GYN with Intermountain Medical Center.

The latest study, released this month in the journal Fertility and Sterility, is too new to have affected doctors’ advice. But its findings add to the growing evidence that air pollution can hurt the unborn, said the study’s author, Matthew Fuller, an assistant professor of surgery at the U.

“What makes this study unique is that [it shows] even a short-term exposure can have really negative fetal impacts — the worst impact, miscarriage,” Fuller said.

Fuller’s team studied more than 1,300 women who went to University Hospital’s emergency room following miscarriages between 2007 and 2015, and reviewed air quality by zip code.

Researchers found that increased levels of nitrogen dioxide were associated with a 16 percent increase in the risk of miscarriage — not a huge increase, Fuller said, but enough for concern.

“The results of this study are upsetting, and we need to work together as a society to find constructive solutions,” Fuller said.

Fuller recommends women speak with their doctor about any health concerns — but it’s not clear that Utah doctors are likely to initiate conversations about air pollution with pregnant patients.

The Tribune contacted more than 20 women who are, or recently were, pregnant. Only four said their doctors and midwives raised the possible risks of air pollution; two of those women were experiencing pollution-related respiratory ailments while they were pregnant, and one was deemed a high-risk pregnancy for other reasons.

“We were lowering risks in every way possible,” said Amy Downing Loveless, who said she was in her 40s and had spent a decade trying to get pregnant when she was expecting in 2014. That summer she left her home in Saratoga Springs and traveled out of state during wildfire season, when smoke began to waft inside her home.

“I did not want to take any chances,” Loveless said.

Several other women said they were worried about air pollution but, absent warnings from their doctors, weren’t sure which protective measures were reasonable and which might be “excessive.”

“I was considering wearing a mask because I had heard about the problems with China’s air quality and pregnancies,” said Janelle Funicello Porter, who is 20 weeks pregnant and lives in Draper. “You always defer to your doctor: ‘Oh, if they’re not talking about it, it’s probably not a big deal and I’m being weird. I don’t want to be that person.’”

On the other hand, Porter said, even the slightest validation from a health care provider would be a powerful motivator.

“Even if a doctor was just kind of like, ‘You know what, it might be a good idea to wear a mask,’ I'd 100 percent wear a mask,” she said.

Many doctors are waiting for more studies that confirm existing research showing links between air pollution and pregnancy complications, developmental problems and birth defects, said Christopher Hutchison, a Riverton obstetrician and Utah chairman of the American College of Obstetricians and Gynecologists.

“We do need to have a lot more research; I don't think we pay enough attention to [the effect of air pollution on pregnancy],” Hutchison acknowledged.

But in the meantime, doctors have to be careful not to oversell the certainty of existing findings in the recommendations they make to patients, Hutchison said.

“Usually by the time you get one study out, it's about five years … to validate or disprove it,” he said.

Before that, he asked, “is [the evidence] enough for me to say, as a doctor, ‘You know what, Mrs. Jones, you need to wear a mask because we have an inversion coming around?’”

Ponder, a member of the advocacy group Utah Physicians for a Healthy Environment, said she discusses air pollution with a majority of her patients — but not all of them. She informally polled eight other obstetricians in her practice, who reported having very limited discussions with their patients about air pollution. Most were discouraged by a sense of helplessness.

“If it does come into the conversation, it’s ‘Yes, it’s bad for you. Talk to your legislators,’” Ponder said. “Other responses: ‘I don’t know what to tell them ... to do about it’ and ‘I don’t want to tell them things that are going to make them bummed out.’”

But several women said they already are bummed as they watch the cycle of reds, oranges and yellows in the state’s air quality danger ratings. It’s hard to believe that a developing fetus is safe from the same pollutants that regularly force Utah schools to hold recess indoors, they said — and while being warned against everything from blue cheese to kitty litter, it’s hard not to worry that bad air will prove even worse for their pregnancies.

“I try not to Google pollution [and] pregnancy dangers because that gets me going down a scary paranoia rabbit hole of doom,” said Adria Milewski, who is 21 weeks pregnant and lives in Millcreek.

Even without internet doom or doctors’ orders, Milewski and others said they are taking action. Some have spent hundreds of dollars on air filters for their homes and downloaded apps with detailed air quality reports. Milewski, like Loveless, has left the state amid poor air conditions during her pregnancy. “I was lucky to be able to,” she said.

But Milewski and others described these measures with apologetic disclaimers of “overkill” and “paranoia.” In a world where women are policed for any risk to their unborn babies but can also be ridiculed as hysterical for their health concerns, it can be hard to make confident decisions about a potential problem where doctors are mostly silent.

“Maybe doctors should tell us about this,” Porter said. “Otherwise I just feel like an over-cautious weirdo."

In general, Porter added, women may struggle to raise the question with their doctors if they have had their worries dismissed before.

“There is something about being told that your concerns are unsubstantiated that actually hurts and makes you question your own sanity,” she said. "It’s embarrassing enough to keep you from asking any more questions.”

Fuller and Ponder encouraged expecting moms to trust their instincts if something seems unsafe and not worry about coming off as overwrought.

“I already walk my dog with a welding mask on,” Ponder said. “Literally, a mask for welding, on bad air quality days.”

“I think women are right to be concerned about this,” Fuller agreed.

But all the doctors interviewed shared concerns that couples who struggle with miscarriage will believe they didn’t do enough to avoid air pollution, when the truth is there is no way to know if that is behind any individual pregnancy loss.

“I don't want for women who do miscarry in January to say, ‘Gosh, if I had just done this.’ Women do carry this burden of self-blame,” said Kirtly Parker Jones, a retired specialist in reproductive endocrinology and infertility and board member for Utah Physicians for a Healthy Environment.

“It's pretty clear that some small percent of losses seem to be related to poor air quality,” she said. “Don’t be completely panicked. … It’s not a 10-times increase in risk, just a small risk.”

Jones urged pregnant women to “do some simple things around your home. Do some simple things about your behavior.”

Among the suggestions from Jones, Ponder and Fuller:

• Avoid going outside on bad air days if possible.

• Wear an N95 particulate respirator face mask if you go outside on bad air days and ensure the seal is tight; common surgical masks do not filter out particulate matter.

• Limit driving on bad air days, to avoid contributing to and exposure to pollution. Don’t idle the car, especially around schools.

• Use the “recirculate” button in the car to prevent pollutants from being ventilated into the cabin.

• Mind indoor air quality in particular; Ponder and Jones recommended PurpleAir.com for outdoor air quality updates and indoor monitors for purchase.

• Install carbon or charcoal air filters — the only type effective for nitrogen dioxide, the pollutant identified in Fuller’s study as a miscarriage risk.

But, Fuller acknowledged, “most women can't afford a $600 air filter in their house.”

Because the highest-pollution neighborhoods tend to house lower-income families, and filters can be pricey, air pollution is “one more thing that's going to drive a wedge between the health of those who can afford and those who cannot,” Ponder said.

The most effective solution would be public action, such as restrictions on industry and motorists, Ponder said.

“Are you only pro-life and pro-family when it suits your checkbook?” she asked.