“They are all around us”: obstetrician says discovery of microplastics in human amniotic fluid is deeply concerning


A team of researchers and doctors from Ostrava recently demonstrated the presence of microplastics in human amniotic fluid for the first time ever. Prior to this study, it had always been assumed that the placenta would prevent any such particles from reaching the foetus, but the presence of microplastics was confirmed in nine out of ten women in the study. To understand the significance of this finding and what it could mean for the health of babies and expectant mothers, I spoke to Ondřej Šimetka, one of the study’s authors.

Microplastics | Photo: © Will Rose,  Greenpeace

I'll start with a very basic question - what are microplastics, how do they form, and how small are they?

"Any plastic material smaller than 5 millimetres is called a microplastic, but in our study, we dealt with particles within the range of 10 to 50 micrometres - 10 micrometres is 0.01 millimetres, so a very tiny thing. Microplastics are either produced as part of our clothes, make-up, beauty products and so on, or they are the product of degradation of larger plastic materials. And they are all around us."

How do microplastics find their way into our bodies and eventually into the placenta and amniotic fluid?

"There are a few ways. You can swallow and ingest them, or you can breathe them in, or they come to your body through the skin or mucosa, so it can be through a cream or lotion. Then it goes into your bloodstream and it travels through the body, and if the woman is pregnant then it eventually travels to the placenta.

"Historically, we would think that these particles would stop in the placenta as the placenta should work as a sort of barrier to protect the baby developing in the uterus. But that is obviously not the case.

"There was an article published in 2021 which confirmed the presence of microplastics in the placenta, and so we thought we would look a bit further, into the amniotic fluid as well. So it travels through the placenta, it gets to the umbilical cord, to the blood, to the foetus, and the foetus probably urinates it out and this is how it appears in the amniotic fluid."

So the first indication of the presence of microplastics in the placenta came in 2021 - why did it take so long for people to look into this?

"I don't know - it's just a very new area of interest. I think we should really be worried about the environment that we live in."

Ondřej Šimetka | Photo: ČT24

As I understood it, the samples for the study were taken from women who had suffered premature amniotic fluid drainage.

"Yes, and that's because no ethical committee would approve taking a sample of amniotic fluid from a healthy pregnant woman. That's the tricky part - this is why it's so difficult to do any studies on pregnant women.

"So we used women with pre-term premature rupture of membranes - basically the complication of premature delivery - and in our clinical protocol, these women undergo amniocentesis anyway. We take a sample of their amniotic fluid and examine it for inflammation, for the presence of infection in the uterus. Then we divide them into groups and if there is no infection then we can wait with the delivery.

“Since we take a sample of the amniotic fluid anyway, we decided to examine it for the presence of microplastics. So it's a very select group of patients.

“We don't know if there are microplastics present in women with normal pregnancies - probably yes, but it's not confirmed.”

I guess this study doesn't necessarily prove that there's a causal link between microplastics and the complications these women suffered during their pregnancies - or does it?

"We will have to investigate further. Women with premature rupture of membranes can be divided into four different groups, four different types of preterm delivery based on whether there is infection or not. So we will have to probably take more samples from more women and see if there is any difference between them.

"We also want to investigate foetus urine and the umbilical cord to confirm that it gets to the baby through the bloodstream."

Illustrative photo: sbtlneet,  Pixabay,  Pixabay License

And it's already been confirmed in mice, that it causes pregnancy complications?

"There have been studies done in the lab on mice. One study proved that the presence of plastic material was linked to the malfunction of the placenta and the mice babies were born smaller. But we don't know how valid this hypothesis is in humans, we have to investigate."

How will you investigate it in humans if it's hard to get studies on pregnant women approved by an ethical committee?

"We will definitely continue the work with the group of women that we worked with before - we'll have to take more samples and look at the placenta, the functioning of the placenta. We'll see - it's going in many directions."

Do you have to get permission from the women first in order to use their amniotic fluid for the study?

"Of course, this is a study which has been approved by the ethical committee, it has funding, so it's very rigorous."

Photo: Filmbetrachter,  Pixabay,  Pixabay License

Is there anything that pregnant women or indeed anybody can do to protect themselves from microplastics or to prevent them from getting into our bodies?

"You mean like go to a different planet? [laughs] Plastics are all around us, we produce them in huge amounts, and we should start to be worried about the production and its effects. But we should not panic. We have lived with plastics for a few decades and we still don't know what they do - there is no room for panic.

"But pregnant women should use common sense. Microplastics are in lipstick - something you might never think about - or in creams. Maybe look at the composition of the things you are putting on your body."