AILSA CHANG, HOST:
Extreme heat is raising risks for pregnant women and babies. That's according to a new survey. This report was released by Wellcome, a health research foundation in London. It surveyed a thousand healthcare professionals in five countries on five continents, and nearly all of the experts surveyed have treated a pregnant woman or baby that they think was affected by extreme heat. Now, they are calling for more training and resources, globally, to mitigate this. Rupa Basu is an epidemiologist who studies climate change and its effects on people's health. She joins us now. Welcome.
RUPA BASU: Thank you. It's a pleasure to be here.
CHANG: So can you just first explain, as an epidemiologist, why heat is such a tremendous risk for someone who is pregnant?
BASU: Well, when there's heat exposure, there's a shift of blood going from your vital organs, such as the heart or even a placenta where the developing fetus is. And what happens is because of that shift of blood volume from the vital organs to the subcutaneous, or right just underneath your skin, there's a shift of nutrients that are also being diverted from the developing fetus. And because of that we're seeing an increase in adverse birth outcomes, such as preterm delivery, low birth weight. We see things such as stillbirth. Also, other studies have reported miscarriage. You know, we're seeing fetal heart dysregulation. So all of these types of things are happening with heat exposure, and it's all stemming from dehydration.
CHANG: And how hot does it need to be for all these ripple effects to begin occurring?
BASU: That's a really important question because I always hear the term extreme heat, and what I really want to talk about is that it doesn't really take extreme heat to see these health effects. In the studies that we've conducted in California, most of them actually look at just apparent temperature, which is a combination of temperature and relative humidity. And that's just the background levels of heat exposure that we've had in the past - nothing about heat waves, nothing about extreme heat. And even then, we are seeing these adverse birth outcomes such as preterm delivery, low birth weight and stillbirth occur.
CHANG: Well, do you think that these problems is something that we should expect to get worse as the climate continues to get warmer and warmer and warmer?
BASU: Absolutely. Unfortunately, we're seeing already that heat and particularly heat waves are increasing in frequency, in duration and in intensity.
CHANG: Yeah.
BASU: Right now, we're actually experiencing a heat wave in California...
CHANG: Oh, yeah.
BASU: ...That's lasted - yeah - almost a week, and it's been pretty brutal in that it's impacting the whole state. And I think within the next couple of days, we'll see some relief. But it's also that duration. The fact that it's lasted so long, it doesn't really give the body time to even cool down.
CHANG: So as the climate gets warmer, how are these risks to pregnant women or to newborns going to get worse? What does worse look like in these scenarios?
BASU: So we could start with fetal health. And one of the things that we're seeing is that there's fetal heart rate that increases with increased temperature, and that's actually quite a rapid increase in heart rate that we're seeing in fetuses when there's heat increasing. We've already done some heat wave studies, sometimes with heat wave and wildfire smoke or air pollution, and we're seeing how much more that impacts these outcomes. And that's something that's very troubling because, as I mentioned, the background effects are already pretty high. And so if we're going to see more than this, and particularly in the most vulnerable populations, that's something that we can address - some of this - so that we can focus a lot on prevention.
CHANG: Yeah. Let's talk about that because in the meantime, what can healthcare systems do to help mitigate some of these risks that we're discussing?
BASU: I think the first thing is health education. So educating the medical community about heat risks and some of the outcomes that we can see, such as adverse birth outcomes. If we don't know that, you know, pregnant people are at increased risk from heat exposure, then they will not take precautions. So that's the most important thing.
CHANG: Yeah.
BASU: I think another big thing is public health messaging. We need to make sure that we're getting this messaging across so it's not just staying with scientists and with physicians and midwives and doulas. We need to make sure it gets to the vulnerable populations themselves, as well as their caretakers and the community.
CHANG: Epidemiologist Rupa Basu - she studies climate change and its effects on people's health. Thank you very much for joining us today.
BASU: Thank you for having me. It was my pleasure.
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