Heat waves are dangerous during pregnancy, but doctors don't often mention it
LULU GARCIA-NAVARRO, HOST:
As we saw this summer, heat waves are a huge threat to people's health. Doctors are now finding that one group in particular is vulnerable, and that is pregnant women. NPR's Lauren Sommer reports on how climate change is becoming a part of prenatal care.
LAUREN SOMMER, BYLINE: Being 7 months pregnant is not exactly comfortable. Then there's being 7 months pregnant in 110 degrees with a broken air conditioner.
KEISHELL BROWN: (Laughter) It was the most challenging time.
SOMMER: Keishell Brown lives with her three kids and grandma on the west side of Fresno in California's Central Valley. She's expecting her fourth, a baby boy, this fall. The heat wave meant that air conditioning repair services were booked up for at least a week.
BROWN: You know, we just kept telling the kids, we're going to get through it.
SOMMER: It happened during the hottest July ever recorded in Fresno. Temperatures were hotter than 99 degrees on every day that month except one.
BROWN: Like, my doctor told me, if it's over 103, 104, do not go outside if I'm able not to. You know, make my appointments early.
SOMMER: But with three kids to take care of, it's not easy to avoid the heat. And Brown says it's the same for the women around her. She's part of Fresno County's Black Infant Health Program, where a group of 10 expecting moms meet each week.
BROWN: We just encourage each other - what it's like, you know, being Black, pregnant and now, you know, in this society.
SOMMER: This part of the Central Valley already has some of the highest rates of preterm birth in California. It's even riskier for Black mothers.
BROWN: One of the girls in the group - you know, she didn't have transportation, and she's running to all these appointments on the bus and then goes into preterm labor.
SOMMER: Now researchers are finding that extreme heat could be one of the reasons why.
RUPA BASU: It was actually quite shocking to see that all women were at increased risk.
SOMMER: Rupa Basu is an epidemiologist at California's Office of Environmental Health Hazard Assessment. At the beginning of her career, she studied how heat can be dangerous for the elderly. Not much was known about the risk for pregnancy, but then she became pregnant herself.
BASU: I would feel my body just really warm up. And I'm like, this is what I've been writing about in the elderly and in infants, and maybe pregnant women are also feeling this. You know, maybe I'm not alone.
SOMMER: Basu looked at 60,000 births in California and found that for every 10 degrees it's hotter, the risk of preterm birth goes up 8%. For Black mothers, it's twice that. Other studies have found similar risks.
BASU: Really, what we think is that, with heat exposure, dehydration is really the root cause.
SOMMER: Basu says dehydration triggers hormones in a woman's body that causes blood flow in the uterus to drop and can trigger contractions. Heat also raises the risk of stillbirth and low birth weight.
NATHANIEL DENICOLA: What I've been telling patients recently - it really is a bun in a really hot oven, and that's a dangerous scenario.
SOMMER: Dr. Nathaniel DeNicola is an OB-GYN who's also an environmental health expert for the American College of Obstetricians and Gynecologists. He says with climate change making heat waves increasingly common, the impact is already showing up in OB-GYN offices, but many pregnant women aren't aware of the risks.
DENICOLA: More needs to be done in terms of training a whole generation of women's health providers that we should be talking about this not just as problems come up but really kind of routinely and prophylactically.
SOMMER: DeNicola's association recently put out clinical guidance about heat for OB-GYNs to use with patients, but he says it can take 17 years for medical guidance to reach widespread use.
DENICOLA: However, in this last year, like in telehealth, that was really more like 17 minutes. And I would say the climate crisis, while it's not yet seen in the same kind of urgency as the global pandemic with COVID-19 was, it's every bit as urgent.
SOMMER: He and other experts say a good place to start - when public health alerts go out about heat waves, make sure they specifically mention pregnant women, too. Lauren Sommer, NPR News.
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