Do microplastics in the body affect pregnancy?

Microplastics have been found throughout the body, including in placentas and reproductive organs. What does that mean for pregnancy?

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  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 an 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 digging into microplastics and what we know about their impact, specifically on reproductive health. Hey, Kathleen.

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  Hey, Flora.

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  What led you down this path?

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  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 2024, where researchers studied 62 human placentas after birth. And placentas are super interesting, as I am 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.

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  Yeah, it's like the weird organ anomaly.

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  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 have found them in testes, in breast milk, in follicular fluid, even something called the meconium, which is a fancy word for baby's first poop.

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  So, OK, so, I mean, obviously, this sounds alarming. Do we know if it's meaningful? Like, do we know the impacts?

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  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.

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  What are the challenges to studying this?

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  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 foolproof. 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.

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  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.

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  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?

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  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 unsettling. 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 researchers in this space. Her name is Dr. Phoebe Stapleton.

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  She's at Rutgers University in New Jersey, and she's specifically studying how microplastics travel during pregnancy. And so I talked to her, and here's a little bit of our conversation.

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  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.

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  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 250,000 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.

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  What I am aware of, though, is how many exponential micro and 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.

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  One thing that's so interesting to me about this field is that you're, it appears that you're sort of working on the mechanisms and the standardization from the ground up. Like, it is, 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?

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  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, OK, 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.

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  What is your lab going to be focused on, you think, in the next, let's say, like, five to 10 years? Or what are the big questions you'd really like to explore?

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  So many studies in this maternal fetal space focus on the fetus, or focus on the offspring, for good reason. That's, you know, the next generation. Those are essentially the future. And so understanding what health effects they have is, 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

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  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, 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

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  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.

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  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?

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  So I really appreciate that, as one of the questions, because I've had two kids myself, and that mom guilt is for real. That is a thing. And you second guess every decision that you made before you were pregnant, and 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

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  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 guilt is a thing, and, and we know that that, that stress is not good during that pregnancy time as well. So control the things that are within your wheelhouse, and gotta let some of the other stuff go.

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  So that's just a little bit of my conversation with Dr. Phoebe Stapleton at Rutgers, and I think that's good advice.

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  OK, Kathleen, what are you keeping an eye on next?

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  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.

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  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 2060. So, I mean, the big question is, is anything going to change?

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  Science Friday producer Kathleen Davis, thanks for filling us in.

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  You're welcome.

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  If you want to read Kathleen's full story about what we know and don't know about microplastics in human health, go to our website, sciencefriday.com/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-CY-FRY is our number. We'll catch you next time. I'm Flora Lipton.