Sign up for TPR Today, Texas Public Radio's newsletter that brings our top stories to your inbox each morning.
Texas has already seen temperatures hitting over 100 degrees this summer and medical experts are now warning about the dangers of extreme heat for pregnancies.
Pregnant women and their fetuses are particularly vulnerable to extreme heat, even in the early stages of pregnancy, according to Dr. Lindsay Darrow professor of epidemiology in the School of Public Health at the University of Nevada Reno.
“There's a lot of growing evidence that exposure to extreme heat can lead to adverse pregnancy outcomes, things like preterm birth, stillbirth, potentially miscarriage,” said Darrow.
The World Health Organization advises that a single day of exposure to extreme heat is sufficient to negatively affect a pregnancy. Darrow said the longer the exposer to extreme heat, the more likely a pregnancy will be impacted. And high humidity is also a factor.
“We do absolutely know that humidity affects how hot a person feels and a person's ability to cool off. It's almost certainly involved when we think about risks for pregnancy,” she said.
Darrow said researchers are working to pinpoint how extreme high temperatures interact with the biological mechanisms of pregnancy. It appears that there are multiple factors including dehydration for the expectant mother.
“One hypothesis is that dehydration leads to a change in uterine blood flow, and that can trigger uterine contractions and lead to early labor and early delivery, she said.
There is also some evidence that extreme heat can increase the risk of premature rupture of the membrane, that's a woman's water breaking. “So if there's an association with a woman's water breaking, that is going to lead to early birth as well,” she said.
And extreme heat can trigger inflammation. “And inflammation is a concern in pregnancy as a potential trigger of labor.”
Darrow said because of climate change and heat waves becoming more common and intense, more research is needed. But it’s clear that extreme heat is becoming a much bigger public health issue.
