Wildfire smoke presents danger to pregnant women, unborn babies

Studies link smoke to miscarriages, preterm birth
Posted at 12:55 PM, Sep 21, 2021

SAN DIEGO (KGTV) -- Exposure to wildfire smoke can lead to miscarriages and preterm births, according to new research published this month.

One study followed a group of rhesus macaquesat the California National Primate Research Center. Forty-five of them became pregnant during November 2018 when the Camp Fire tore through Northern California.

Because of its proximity to the center at UC Davis, the animals presented a unique opportunity to study the impacts of smoke on pregnancies.

"They live outside. They eat and drink and breathe outside. So, being able to study the impact of this wildfire smoke on their reproductive outcomes was ultimately what we were looking into," says Dr. Bryn Willson, the lead author of the study.

Of the 45 macaques, 37 carried their pregnancy to live birth. Eight had miscarriages. That related to an 82% success rate, significantly lower than the 90% average success rate from the prior nine years at the center.

The research suggests wildfire smoke exposure early in a pregnancy can lead to a higher rate of miscarriage.

"Our bottom line would be that although wildfire smoke is a hazard to everyone, it could be especially hazardous during an early period of pregnancy, where women may not even be aware that they are pregnant," says Dr. Kent Pinkerton, a Core Scientist at CNPRC.

In another study from Stanford, researchers found wildfire smoke may have led to as many as 7,000 premature births from 2007-2012.

Researchers in that study looked at birth data from across California and cross-referenced it with areas in the state that had higher exposure to wildfire smoke.

According to the study, "Each additional day of exposure to any wildfire smoke during pregnancy was associated with an 0.49% increase in risk of preterm birth."

That means a pregnant woman exposed to smoke for as few as five days in her pregnancy had a 2.45% higher risk for premature birth.

"It's not surprising at all," says Dr. Tarik Benmarhnia, a public health specialist at UC San Diego Health and the Scripps Institution of Oceanography.

He says wildfire smoke is the number one problem when it comes to air pollution across the state. Dr. Benmarhnia adds the combination of more wildfires and stronger Santa Ana and Diablo winds means everyone in California is at risk, not just people who live near the fires.

"The problem with smoke is that smoke can travel very far away from where the fire takes place and can impact huge populations," he says.

With that in mind, experts say people should do more to avoid wildfire smoke. That includes staying inside when smoke impacts air quality, using an air purifier, and wearing a mask if you have to go outdoors.

"Every pregnancy matters," says Dr. Willson. "That's why we're bringing it up now."