Study finds unhealthy air quality from wildfires can affect fertility treatments

Oregon Health & Science University researchers found women undergoing fertility treatments can face potential problems from poor air quality, an issue that’s expected to get worse as climate change increases wildfire activity across the West.

In a new study published in the journal Fertility & Sterility, OHSU researchers investigated the impact of unhealthy air quality from the 2020 Labor Day wildfires on patients undergoing in vitro fertilization treatment, or IVF. The research team studied 69 patients who underwent ovarian stimulation and IVF treatment during the six weeks preceding the 2020 wildfires, which caused 10 days of unhealthy air in southern Oregon making it one of the worst places in the world at the time. They found that poor air quality affected the treatments.

“The unfortunate reality is that we are seeing more wildfires because of climate change, so I worry about how this will continue to affect not only patients undergoing fertility treatments, but all individuals who are trying to conceive,” said the study’s lead author Dr. Molly Kornfield, assistant professor of reproductive endocrinology and infertility at the OHSU Center for Women’s Health.

Every year, tens of thousands of babies are born through assisted reproductive techniques. In 2021, according to the federal Department of Health and Human Services, they accounted for 2.3% of newborns in the U.S. That means that in Oregon, more than 900 were born through assisted reproductive technology out of the more than 40,000 babies born in the state that year.

Researchers find patients exposed to wildfire smoke had fewer blastocysts

The researchers found patients who were exposed to wildfire smoke had fewer blastocysts, which are clusters of 150 to 200 cells that form during embryonic development and can be immediately placed in a uterus or frozen for future implantation. Patients with no wildfire smoke exposure had more blastocysts, which are especially important for people trying to conceive through IVF.

During a standard in vitro treatment cycle, patients get one to two weeks of hormone injections to stimulate the ovaries and grow eggs. An egg is then retrieved and fertilized by sperm to grow blastocysts, which can develop into an embryo that eventually becomes a fetus.

The smoke didn’t completely thwart the treatments, however: Most of the patients ended up getting pregnant but fertility providers may want to consider delaying IVF or embryo transfer for high-risk patients when the air quality is particularly poor, Kornfield said.

The study didn’t look at traditional pregnancies that didn’t involve fertility treatments. But Kornfield said based on other studies, pregnant patients who face poor air quality should try to stay indoors as much as possible and use air filters in their home. OHSU’s Center for Women’s Health treats about 500 patients with fertility needs annually. Though based in Portland, the center treats patients from across the state.

“If I had a patient who lived in eastern Oregon and was especially impacted by the wildfires, I would be more concerned about that patient and really poor air quality,” Kornfield said.

That also means providers need to protect patient treatment areas and laboratories. OHSU’s fertility lab has advanced air filtration systems that can respond to poor air quality. During a routine fire season, there’s no need to reschedule treatment, but the 2020 fires were unusually bad for air quality, Kornfield said.

“For particular patients, in particular situations, we may consider delaying or canceling if things can be predicted, and then advising patients to take as much precaution as possible,” Kornfield said.

Even amid wildfires, life finds a way, the study found. While the smoke impacted embryonic development, the treatments went well when the wildfires ended.

“It gives an element of hope that even during these seasons, as long as you’re protecting yourself as much as possible,” Kornfield said. “But we should just do our best, since these are increasing, to try and protect ourselves.”