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Getting exposed to heat and wildfire smoke can impact a baby growing in a pregnant woman's womb. Doctors say that's something to keep in mind as summer heat and wildfires get underway, and they're calling for more attention to be given to the climate risks for pregnant people. NPR's Alejandra Borunda reports.
ALEJANDRA BORUNDA, BYLINE: When someone gets pregnant, their body goes through a lot of changes, says OB-GYN Nathaniel DeNicola.
NATHANIEL DENICOLA: During pregnancy, blood volume increases by about 50%.
BORUNDA: DeNicola is an environmental health expert with the American College of Obstetricians and Gynecologists. He says, that's like adding a two-liter soda bottle of blood to your body. And the heart remodels itself to pump all that extra blood.
DENICOLA: Some studies have shown that remodeling is close to, like, what an endurance athlete, like, a marathon runner goes through.
BORUNDA: All those changes help the growing fetus. But DeNicola says the changes also stress a pregnant body.
DENICOLA: All of this makes it harder for pregnancy to dissipate heat. You know, there's a lot of things that are necessary for the pregnancy that are not necessarily great for mom.
BORUNDA: And they're not great for a growing baby either. A new study published in the journal Environmental Science & Technology found that babies whose mothers dealt with high heat during the first trimester, or even in the month before conception, were more likely to be small in the womb. Roxana Khalili is the lead author of the study and a researcher at the University of Southern California.
ROXANA KHALILI: Preconception and first trimester were important time periods for heat stress exposure and linked to having an infant that was smaller in size.
BORUNDA: The study looked at women living in what are called climate-vulnerable neighborhoods in Los Angeles. They're often hotter than the surrounding areas, and the people living there are less likely to have ACs for heat or air filters for smoke.
KHALILI: The effects of heat stress during preconception on having a small-for-gestational-age baby were different among women that lived in a more climate-vulnerable neighborhood, with the odds being nearly double for those living in the more climate-vulnerable neighborhoods.
BORUNDA: Wildfire smoke exposure was also linked to smaller babies in the womb and at birth. And Khalili says, dealing with both heat and smoke at the same time seems to be worse for babies.
KHALILI: With climate change, these effects aren't only becoming more intense, but also they're occurring simultaneously.
BORUNDA: Rupa Basu is a climate and health expert at the University of California, San Francisco. She says, there needs to be more attention on the climate risks to pregnant people.
RUPA BASU: I think a lot of people who are pregnant don't even realize they're at high risk, you know? So it's like, if you don't know you're at high risk for something, then you don't take precautions.
BORUNDA: The precautions aren't that complicated, either. The OB doctor, DeNicola, tells his patients to stay cool and drink a lot of water when it's hot and to wear a mask outside if it's smoky. Alejandra Borunda, NPR News. Transcript provided by NPR, Copyright NPR.
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