Pregnancy is a fragile time and there are countless factors that play into whether a pregnancy can be carried full-term with a healthy outcome for mom and baby.

Well, it turns out there's a new risk factor that can dramatically increase the risk of preterm birth and that's extreme heat.

High temperatures have been found to have a direct impact on sending pregnant people into preterm labor.

I had the privilege of working on this story with my esteemed colleague at NJ Spotlight News, Lilo Stainton, and the incredible team at Climate Central, which is an independent climate and science news group based in Princeton.

Together we spoke with some moms and several experts in the field who shared their findings from a number of recent studies that connect the risks of extreme heat with poorer pregnancy outcomes.

Here's that story.

The main thing on your mind is to take care of your body so you can take care of your baby and to be that uncomfortable and that hot.

You just want to sit down and do nothing.

Rebecca Weber knows all about extreme heat in pregnancy.

She delivered her second baby in September of 2023, so she spent her third trimester in the hottest months of the year.

It made it hard to monitor myself and make sure that I was okay.

Just doing regular tasks, walking to the park or, you know, taking my son on a walk or something, you know, you just really over stress about making sure you're feeling okay having water with ice.

Like Weber, many pregnant people struggle to keep cool during pregnancy.

That's because the body has a harder time regulating its core temperature during gestation, making extreme heat a real danger for them, says doula and child birth educator Jill Wodnick.

The clearest issue is preterm labor.

And so, of course, we want to prevent low birth weight and preterm labor, and that's where extreme weather is an absolute risk factor.

In fact, high temperatures can trigger preterm labor.

Those findings come from several recent studies, including one by the National Institute for Health and one by Duke University, which Ashley Ward helped to conduct.

A lot of people focus on heat during the day, and what we see in our research is that overnight temperatures actually lead to higher risk of preterm birth than even those extraordinarily high daytime temperatures.

When the temperature fails to drop below 75 degrees overnight, at 75 degrees, you start to see a 4% increase in preterm birth, but as that gets higher and you get to say 80 degrees overnight, that gets to a 7 or 8% increase in preterm birth.

Ward says you don't need more than one or two hot nights to trigger these responses, and there are impacts on the health of the mother and on the fetus in utero, explains Rutgers University researcher Stefania Papatheodou.

Pregnancy-related diseases like pregnancy-related hypertension, preeclampsia, or even like, you know, other events that are more rare have been associated with exposure to extreme temperatures.

There's some research that supports that depending upon the time of exposure in the pregnancy can actually lead to some birth defects.

Our studies have shown that in general exposure to extreme temperatures leads to smaller fetal size and particularly the brain parameters.

So knowing all the increased risks, what should pregnant people do, especially during heat waves like we've already experienced this summer?

First of all, they need to be aware of the risks.

They need to avoid outdoor exposure as, you know, if they can.

If their work involves being outdoors in high temperatures, they need to be aware of that and avoid it as much as possible.

For those who do work outdoors, there's a new federal law called the Pregnancy Workers Fairness Act that offers workplace accommodation from the beginning of pregnancy to a full year after delivery.

For some, that could include moving to an indoor job during that time period.

This is a piece of support that pregnant women may not know that they have these legally protected rights for accommodation, especially in high heat situations at the workplace.

Wodnick says to be vigilant and looking for signs of heat exhaustion.

If there's headache, if there's dizziness, that really is an immediate call to your health care provider and/or getting 911 involved because we, especially in the third trimester, would never minimize that as a risk factor.

And then other things, just even noticing the skin, right?

The skin really tells us about our own hydration levels, noticing our own output, if there's difficulty urinating, all of these elements that you can notice in your own pregnancy.

For Weber, staying cool often involved water.

It was like, get me to the closest tub of water.

Which is actually backed by science.

Taking a cool shower when you come back from work or from being out in the heat.

Using cool water and submerse your feet over your ankles or submerse your arms over your elbows.

And in your home, especially if paying for air conditioning is a challenge.

Prioritize cooling your bedroom.

That's where you sleep.

That's where you're going to get most of your recovery.

And so a lot of people might think, oh, I'm going to use this air conditioning to cool off my family room where we all gather.

It's more important for your health outcomes that you cool your bedroom.

It also, you can shut the door.

It can also reduce costs.

Weber says she did prioritize cooling her bedroom at first with her window AC unit before she and her husband invested in central air conditioning.

But she also took advantage of community services when keeping the house cool was a challenge.

Once I was pregnant and having children, I was aware that my body carried this weight of importance and this weight of responsibility.

And so in that responsibility was taking care of myself, not being overheated.

Taking care of, there's a reason that cooling centers are open and those things are important for communities, especially communities of color.

As Rebecca Weber just said, we know communities of color are most impacted by extreme heat.

And according to Climate Central's research, over the last five years, New Jersey's experienced 22 days out of the year that are considered to be pregnancy heat risk days.

More than half of those are the result of climate change.

Let's get into it.

With us now is NJ Spotlight News Healthcare writer Lilo Stainton and Melba Newsom, who's a reporter for Climate Central.

Great to have you both.

Melba, I want to start with you.

What is a pregnancy heat risk day?

What does that mean?

That refers to the days where the temperature reaches a certain percentile that is deemed dangerous for the health of a pregnant woman and their offspring.

And that is not a specific temperature, right?

That is it's basically depending on where you live, a percentage higher than what you're used to?

Exactly.

We're, they are looking at 95th percentile where the temperature is reaches that point where it can be detrimental to the health of the mother and the child.

Lilo, we've done reporting on on pregnancy risks.

As with most things, we know that poorer communities and communities of color tend to fare worse.

What can you tell us about what you've learned about urban heat zones through this reporting?

Yeah, well, I mean, it seems like it's one of these things where with so many social determinants of health, we have compounding issues, right?

So, you know, people who live, people who are maybe lower income may live in a more crowded condition.

They may they may have less access to air conditioning, likely more urban.

So fewer trees around, fewer green spaces, fewer options to cool off, fewer pools.

And those things just compound.

And so, you know, we're in a state where black women already are seven times more likely to die while, you know, pregnant or in childbirth or after than white, their white counterparts.

So this is really, these start, things start to add up and can really be deadly for mothers and infants.

Melba, I know that you focused a lot on rural communities and how there are different and yet somehow similar struggles that folks who live in urban communities face when it comes to extreme heat and pregnancy.

Help us understand that.

Well, I focus, I try to bring that up because people, we do and we have done a lot of good work about letting people know about urban heat islands and things, but there is also a great deal of danger if you live in a rural community precisely because there aren't any resources.

So even though there may not be as much concrete or, you know, traffic that is driving up the temperatures in the rural areas, there's so there are like a lot fewer resources and housing tends to be worse.

That's where, you know, they, the air conditioning people don't have it.

There's a lot more energy poverty.

So those compounding factors kind of supersede what may be going on in an urban area and just not having cooling spaces where people can go.

So it's important that we don't ignore people who live in those communities as well.

How much of that is also tied to a lack of access to transportation, be it public transportation or, you know, a car even?

Well, that is absolutely true.

What I do see though in urban areas is like at bus stops, some of them aren't sheltered.

So people maybe end up waiting an hour for a bus in 90 degree temperatures and that's, you know, very detrimental.

But a lot of the factories and things, I live in North Carolina and a lot of the factories are located in rural areas and they aren't properly heated or cooled.

And so that's where a lot of agricultural work goes on.

So those kinds of things really work into adding to the burden of people who are, you know, dealing with heat illnesses.

And I touched on it in my story, but there is a new bill that does protect workers who are outside pregnant workers and even up to a year after delivery, do have the right to request an indoor position, even if that's not how they typically do their job.

A lot of women we know don't know that.

They have that protection available to them.

Lilo, can you put this in the broader context of New Jersey and all that the state, really led by First Lady Tammy Murphy, has been doing to try to bring down some of those statistics that you mentioned, the alarming number of pregnancy or maternal mortality rates?

Yeah, I mean the state has done a lot.

There's a story, a set of stories I did that published today about one of the sort of crown jewels of the First Lady's Nurture New Jersey program.

And there's a home visit program that helps first, you know, moms who are just home from the hospital with a newborn.

And I just think, I think one of the things that shocked me about this story was a lot of the nurses that are doing those home visits are a great resource on these kinds of things, these kinds of issues.

I talked to one of them, Jenny Sherlock Globe in South Jersey, and she was saying, you know, they spend a lot, they do a lot of education with their clients to warn them about this.

And one of the things we learned in the, through the reporting was it's not just the high heat during the day, it's also the high heat when it doesn't go down at night.

Your body needs time to recover.

And I think, you know, the state has done, to come back to your question, the state has done a lot around maternal mortality.

But still the need to get the message out there that, you know, some of these things that new moms may think are not, you know, life or death, like a headache or swelling arms may in fact be life or death.

And in all the reporting we've done, I haven't heard extreme heat listed as a major contributor to any of the maternal health outcomes.

And yet we see there are these really specific stats about, like you said, the temperature not coming down below 75 degrees at night, leading to what, a 4% increase in the risk of preterm labor?

Yeah, I think it was 4%.

And I mean, and that result is almost just days later.

It doesn't take extended periods of nighttime high heat.

It's quick, a couple degrees more and you double that risk.

You know, it was really interesting some of the researchers we talked to, what they had to share and what they're finding out about these dangers.

Absolutely.

Melba, you had the chance to speak with several moms, some who are pregnant, who've already delivered in summertime, some who are expecting and really suffering with this heat wave that we've been experiencing for weeks now in New Jersey.

What did you hear from them?

What I heard was most of them, even though they know they're like really uncomfortable and how uncomfortable it is being pregnant, most people don't realize that there's an actual, like Lilo said, there's life, this is a life and death issue, how this impact goes beyond being just uncomfortable to being in danger.

And so that's why I think what the First Lady is doing to let people know and that the different non-profits that are working to make sure people realize this is how seriously you should take this and recognize the signs because a lot of people just weren't aware.

They're just thinking this is what goes on when you're pregnant, but you are really in a heightened situation.

And when we talk about who's most vulnerable of the heat, a lot of people are, they just started recently adding pregnant people to that list.

We talk about elderly and young babies, but pregnant people are at a big risk factor for that.

Absolutely.

When we get those national weather alerts and we talk about those vulnerable populations, pregnant people should be a part of that list.

And Lilo, just a few seconds left.

What is some tangible advice for women, especially as they're trying to keep those temperatures cool at night?

And especially when it's hard to afford electricity in the state of New Jersey.

I mean, limit your time outdoors.

If you can, air condition a room, make it the bedroom.

One researcher told us soaking your hands or your feet, your arms and your wrists, elbows even, in cool water can help.

Apparently, this is what the Army does.

So it's a proven technique that helps cool your body.

Excellent reporting.

I'm so proud to have worked with both of you on this story.

Melba Newsom, Lilo Stainton, thank you both so much.

And to check out Lilo's full story and more of our coverage on this issue, head to our website, njspotlightnews.org.

Thank you.

Support for The Medical Report is provided by Horizon Blue Cross Blue Shield of New Jersey, an independent licensee of the Blue Cross Blue Shield Association.

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