Science Friday - Do microplastics in the body affect pregnancy?

Episode Date: August 21, 2026

Microplastics have been documented throughout the human body, including the reproductive system. But the field of microplastics research is very new, and it’s not yet clear if, or how, these tiny particles affect our health. Producer Kathleen Davis has been reporting on the handful of scientists trying to uncover what microplastics mean for pregnancy and fetal development. She joins Host Flora Lichtman to debrief what she’s learned. Read the full story here. This story was produced with the assistance of the Journalism & Women Symposium (JAWS) Health Journalism Fellowship, supported by The Commonwealth Fund. Guests: Kathleen Davis is an audio producer for Science Friday based in New York. Dr. Phoebe Stapleton is a toxicologist and microplastics researcher at Rutgers University in New Jersey. Transcript will be available after the show airs on sciencefriday.com. Subscribe to this podcast. Follow our show on Instagram, TikTok, Facebook, and Bluesky @scifri and sign up for our newsletters. Got a science question that’s keeping you up at night? Call us: 877-472-4374 Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com for information about our collection and use of personal data for advertising.

Hey, it's Flora and you're listening to Science Friday. Microplastics are hard to escape, both the news about them and the petrochemical crumbs themselves. They've been found throughout the human body in the heart, the brain, the stomach, name and organ, and they have probably been found there. But what does this really mean for us and our health? It turns out there are a lot of open questions. Science Friday producer Kathleen Davis got curious about this and spent the last few months, into microplastics and what we know about their impact specifically on reproductive health. Hey, Kathleen.

Hey, Flora. What led you down this path? Yeah, so I feel like like a lot of people, I was getting inundated with headlines about microplastics. And like, they're freaky. I don't like the idea of little pieces of plastic moving around and getting stuck in my body. There was one study that really stuck in my mind, which was from 20,000. 24 where researchers studied 62 human placentas after birth. And placentas are super interesting, as I'm sure you know, Flora, because they grow really fast. They're like specifically grown to

support a fetus. And then they're delivered during childbirth. And so they can actually be studied like in full without harm to the person who birthed it. Yeah, it's like a weird organ anomaly. Exactly. Exactly. And so in this study, they found microplastics in every single one of the placentas that they studied. And so I started going down this rabbit hole of micro and nanoplastics in reproductive health. And there are other studies that I've found them in testes, in breast milk, in follicular fluid, even something called the maconium, which is a fancy word for baby's first poop. So, okay, so, I mean, obviously this sounds alarming.

Do we know if it's meaningful? Like, do we know the impacts? The short answer is no, not really. And I really dug into this topic. I talked to 10 different experts on this. And across the board, they were telling me, like, yes, we know that they are in all of these places in our bodies. But we actually don't know what they're doing. I mean, based on our level of knowledge, like, there is a chance that they're doing nothing.

Probably not. But, like, there is that chance because we just don't know at this point. What are the challenges to studying this? Yeah, so this is a really young field. Like we have actually a lot of information about micro and nanoplastics in the environment, but we've only been studying them in the human body for like 10 years. And so with a new field, it takes a long time to even create the methods for research. I mean, there's been a ton of effort done to even determine like what is a microplastic in a sample versus something else. and those methods still aren't full-proof.

There's also a big concern about contamination in these studies because research labs are just inherently filled with plastic. So making sure that those background levels of microplastics aren't impacting study results has been a challenge in and of itself. So it's a challenging new field, and it is a bit of a niche. And then if you break it down even farther into the people who are specifically looking at the reproductive health side of things, you are really just looking at a handful of people.

Yeah, that's really interesting. It makes me wonder what it's like for people studying this question. You know, obviously there are so many unknowns. They're sort of trying to develop this new frontier of science. How do they think about the risk of microplastics to reproductive health? I mean, that to me was the most interesting part of all of this because, like, to me, as an outsider, it's an intense topic. You know, it's a new field. The implications are. settling pregnancy and fertility is like already super high stakes for people. And then you put in this like unknown contaminant. It's just very sensitive. And it also feels extra important because our plastic use is not going away. I mean, we rely on it a ton. And so I wanted to get a sense of how these researchers think about being on the front lines of this work and how they make sense of the fact that, you know, there isn't really a connection to health effects yet. And so I went to the lab of one of the research. in the space. Her name is Dr. Phoebe Stapleton. She's at Rutgers University in New Jersey, and she's specifically studying how microplastics travel during pregnancy. And so I talk to her, and here's a little bit of our conversation. I think I'm aware that they're in our matrix and we're always surrounded by them. But I'm also aware that at the moment, we don't have a direct health effect link. And in my mind, we're in that moment because we just haven't hit the

dose yet that's going to lead to those health effect outcomes. So what people are being exposed to today, what adults are being exposed to today, they don't have the bioaccumulation yet to have kicked it over into that pathology. However, plastic production is increasing exponentially. Where you have production, you have disposal. That's going to be increasing if it's not already. So I think my focus is much more on what I'm putting out into the world, what I'm disposing of, as it compares to what I'm being exposed to right now. And I say that because I was involved in the bottled water study a couple of years ago that identified the nanoplastics in a liter of water. So well aware, there are 250 to 400,000 nanoplastics within that bottle, liter bottle of water. And that seems like a

really big number and it seems like a really scary number. And I agree with all of those things, except I also realize that those are all invisible. No one recognized that they were being exposed to it prior to those measurements coming. What I am aware of, though, is how many exponential micro-nanoplastic particles would be produced from that liter bottle of water instead. So I think I am working on the aspect to not make such a big plastic footprint myself as much as possible. One thing that's so interesting to me about this field is that it appears that you're sort of working on the mechanisms and the standardization from the ground up. Like it does appear to be so new in that way. What is it like to kind of be in on the ground floor of this research? It's kind of humbling and exciting to be on the ground floor of that research because that's the goal of science is to be on.

that forefront of knowledge and to be one of the individuals able to put some of those building blocks in where, okay, we've learned this about it. And so either we can be responsible for what the next steps or questions are or somebody else can be responsible for the next steps and questions. What is your lab going to be focused on you think in the next, let's say, like, five to ten years? Or what are the big questions you'd really like to explore? So many studies in this maternal fetal space focus on the fetus or focus on the offspring for good reason. That's the next generation. Those are essentially the future.

And so understanding what health effects they have is really important. And seeing if we can correlate some of the cardiovascular disease or metabolic disease, it seems that at the same time that plastics have entered our world, some of these other disease states have entered our world as well. and have increased. And so just understanding if that is a mathematical comparison just happens to be that they're going up at the same time because of other changes, or is there really a scientific reason that we're seeing increase in some of these cardiovascular

and metabolic disease outcomes? So that's one area. And then back to the mom, there's so much that has to change rapidly and precisely when one is pregnant, 50% increase in blood volume, for example, during pregnancy. And how a woman is able to compensate during pregnancy and equally as important, how she's

able to compensate after delivery are components that aren't really well understood yet. And if environmental exposures can affect how she's recovering, that then affects her health, of course, but also her ability to take care of that newborn as well. So getting a good handle on what changes for a woman during pregnancy and that postpartum period after. And if we can help in that recovery period, I think those are the directions our lab is looking at. You know, for a pregnant person, there are so many potential concerns to be aware of, right? And I'm sure it can be incredibly overwhelming. How does this fit into that matrix of concerns?

and like how do you advise them to think about this? So I really appreciate that as one of the questions because I've had two kids myself. And that mom gill is for real. That is a thing. And you second guess every decision that you made before you were pregnant, every decision you made after you find out that you're expecting. And to some extent, decisions after that as well. And the same thing applies to this plastic question.

And so there's just. same idea if you're spending all of your time and energy focused on this answer i guess the one thing that i say about that is that we know stress and anxiety during pregnancy has negative effects that that has concerns for fetal development maternal health all of those things we don't necessarily know what that plastic exposure might lead to yet so part of it is you know being able to work with the knowns, what we do know, making the best decision that you can with the information that you have available to you at the moment, and making new decisions as new information arises. But that mom wheel is a thing, and we know that that stress is not good during that pregnancy time

as well. So control the things that are within your wheelhouse and got to let some of the other stuff go. So that's just a little bit of my conversation with Dr. Phoebe Stapleton at Rutgers, and I think that's good advice. Okay, Kathleen, what are you keeping an eye on next? Yeah, so interestingly, this has become kind of a maha issue. So earlier this year, HHS secretary, RFK Jr., and EPA administrator Zeldin announced this big research initiative that's going to happen over the next five years. It's called Stomp, the systematic targeting of microplastics. It is through ARPA-H, which is kind of this federal research accelerator, and there are three main goals here to measure, target, and then eventually remove microplastics from the human body.

And my sources were all genuinely really excited about this. They all got very busy putting in proposals for this. They want to be involved because in theory it's going to set standards for microplastic research that just haven't existed before. And hopefully it's going to advance this research in a way that will also advance our understanding. of this issue. So it'll be really interesting to see what comes out of that. At the same time, our plastic production is set to almost triple by 2016. So I mean, the big question is, is anything going to change? Science Friday producer Kathleen Davis, thanks for filling us in. You're welcome. If you want to read Kathleen's full story about what we know and don't know about microplastics and human health, go to our website, science Friday.com slash plastics. This story was published with the assistance of the Journalism and Women's Symposium, Health Journalism Fellowship, supported by the Commonwealth Fund. Kathleen Davis did the reporting and producing, and if you've got a comment or a question about this or any of our episodes,

8774 SciFRI is our number. We'll catch you next time. I'm Flora Lichtman.