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Being seven months pregnant is not exactly pleasant. Then there is the pregnancy in the seventh month in 110 degrees heat with broken air conditioning.
“It was the toughest time,” says Keishell Brown, a pregnant mother in Fresno, California. “It was very difficult to sleep. There is no cool air. The fan only blows hot air.”
Air conditioning repair companies were flooded during the heat wave, so it took a week for help to arrive at Brown’s apartment, where she lives with her three children and grandmother. “I kept telling the kids that we would get through this,” she says.
The month Brown’s air conditioning erupted was the hottest July on Fresno’s record since records began in 1887. The maximum temperature fell below 99 degrees in just one day in the entire month.
With extreme heat waves on the rise in a changing climate, doctors note that pregnant women are particularly at risk. Heat waves increase the chances of premature labor, stillbirth, or a baby with low birth weight.
The risk is even greater for women of color, especially black mothers. While women are often advised to stay hydrated during pregnancy, many are not warned about the risks of heat by their doctors.
“I’m sorry for the pun, but it’s really a bun in a really hot oven and that’s a dangerous scenario,” says Dr. Nathaniel DeNicola, a gynecologist and environmental health expert from the American College of Obstetricians and Gynecologists.
Staying out of the heat isn’t always an option
Every week, Brown enrolls in a Zoom meeting with 10 expectant mothers, a support group for Fresno County’s Black Infant Health Program. Both first-time and seasoned mothers discuss how to deal with pregnancy, including how to stand up for themselves.
“We’re just encouraging each other,” she says. “There is so much that we as women and mothers are already going through, and then in 2021 it will be a challenge to be a black, pregnant woman.”
Brown says the statistics around her are painfully clear: Black women may not be taken seriously by doctors. They also face dramatically higher rates of pregnancy complications, premature births, and maternal mortality. In Fresno County in 2020, 9% of births to white mothers were premature, while 13.5% of black mothers had premature births.
The summer heat is another risk to your health and pregnancies.
Temperatures in West Fresno, where Brown lives, are often even hotter than the surrounding area. With few trees, the sidewalk absorbs and radiates heat, creating one of the worst urban islands in the country.
“I definitely feel like it’s gotten hotter,” says Brown. “My doctor told me, if it’s over 103, 104, don’t go outside if I can’t. Make my appointments early.”
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With three kids, Brown says staying indoors all day is often not an option. There is exercise, errands, and work. The same goes for other mothers she knows.
“One of the girls in the group didn’t have a transport,” she says. “And she’s running the bus to all of these appointments and going into premature labor.”
In the heat, it can be even more difficult to follow your doctor’s advice for a healthy pregnancy.
“We don’t have a whole food market or a farmer’s market or anything like that selling fresh fruit and vegetables,” she says. “Everything we need, we have to travel across town to get there.”
How heat endangers mothers
For decades, public health officials have known about the danger extreme heat poses to the elderly and babies. Epidemiologist Rupa Basu started her career studying these groups, but then she became pregnant herself.
“I would feel my body really warming up and I think: I’ve written about this for older people and babies, and maybe pregnant women feel it too,” says Basu, now head of the Air and Climate Department of the California Office of Environmental Health Hazard Assessment.
Basu and colleagues conducted a 2010 study of the effects of heat in California and found that for every 10 additional degrees, the risk of premature birth increased by 8%. Other studies have found even greater effects.
“It was really shocking to see that all women were at increased risk,” she says. “With increased heat exposure, there is an increased risk of premature birth, regardless of race and regardless of the age of the mother.”
For black mothers, however, the risk is almost twice as high, which other research has also shown.
“We really believe that when exposed to heat, dehydration is the root cause,” says Basu. Dehydration causes hormonal changes that “tell a mother that she is going to have a baby. Blood flow in the uterus decreases.”
The hotter the climate gets, the more often heat waves are expected. With a warming of 5 degrees Fahrenheit, an extreme heat wave, which is considered a 1 in 50 year event, could be 27 times more common.
If babies are born before 37 weeks of gestation, they are at increased risk of developmental, breathing, or heart problems, some of which can last for a lifetime. Exposure to heat and air pollution is also linked to an increased risk of stillbirth and low birth weight. A Stanford University study found that between 2007 and 2012, exposure to forest fire smoke in California was linked to up to 7,000 premature babies.
OB-GYNs urged to speak about heat waves
Many gynecologists hear of women who experience preliminary and ultimately temporary labor during heat waves. But patients are often not warned of the dangers of the heat in good time.
“In terms of training a whole generation of women’s health services, more needs to be done so that we should not just talk about it when problems arise, but routinely and prophylactically,” says Dr. DeNicola from the American College of Obstetricians and Gynecologists.
In July, ACOG released new clinical guidance on heat and environmental risks for doctors, advising them “that climate change is an urgent health concern for women and a major public health challenge.”
Still, it can take more than a decade for clinical guidelines to be widely adopted by providers. The COVID-19 has sped up this timeline in some cases, but the warming climate isn’t nearly as important in a doctor’s office. This summer, the world’s leading medical journals identified climate change as the “greatest threat” to public health.
“I would say that the climate crisis is not yet seen with the same urgency as the global pandemic with Covid 19, but it is just as urgent,” says Dr. DeNicola.