Study - microplastics found in placentas associated with decreased fetal length, weight

Microplastics - where do they come from?

Microplastics are small particles of plastic, less than 5 mm (0.2 inch) in length, from the size of a grain of rice to particles that have to be viewed under a microscope, explain Yale Sustainability experts Leigh Shemitz and  Paul Anastas.

Primary microplastics are the 

microbeads found in personal care products, plastic pellets (or nurdles) used in industrial manufacturing, and plastic fibres used in synthetic textiles (e.g., nylon).

Secondary microplastics are 

large plastic materials that . . .  get ground down over time either through abrasion, wind, or sun rays, and become microplastics, . . .  Plastics bags, bottles, and food containers, as well as paints, adhesives and coatings, and electronics are all examples of materials that can break down and release secondary microplastics.

Washing clothes made with synthetic fibers in a washing machine can also release secondary microplastics into the environment. 

Microplastics found in placenta tissue 

Microplastics in the environment are a growing worldwide concern. Several studies conducted by researchers in different countries have documented nano- and micro-plastics in placental tissues.  

Italian researchers reported finding microplastics in four of the six placentas they studied. Their study, aptly titled “Plasticenta: First evidence of microplastics in human placenta,” was published in the journal Environmental International in 2021. A subsequent study, conducted by Chinese researchers and published in January 2023 in the journal Science in the Total Environment, found microplastics in each one of the 17 placentas studied. 

A third study, published in December 2023, found that the contamination of placentas with microplastics has been increasing over time. Science Alerts' Carly Cassela reported on the study conducted by Hawaiian and Brazilian researchers who discovered  microplastics contamination in human placentas increased between 2006 to 2021:

In 2006, only six of the the ten donated placentas contained microplastics. By 2013, nine out of ten placentas were found to be contaminated. In 2021, each of the ten placentas anayzed showed plastic pollution, and the sizes of the microplastic particles were bigger than ever.

Will they harm the developing fetus?

Hawaiin researcher and obstetrician Men Jean Lee Cassela reported the possibility that the microplastics in the placenta found their way into the umbilical cord and then into the baby:

"We believe that the plastics may be floating around in food or being inhaled. It's coming through our digestive fluids or lungs, and the particles are getting absorbed through the gut and traveling through the bloodstream, and then somehow collecting in the placenta during pregnancy," explains obstetrician and researcher Men Jean Lee from Kapiʻolani Medical Center.

"The big question is, as it's traveling through the placenta, can it get through the umbilical cord and then to the baby? We don't know that right now." [Emphases added.]

Researchers at Fudan University in Shanghai, China, as Food Packaging Forum author Lisa Zimmerman reported, also found microplastics in breastmilk, meconium, infant feces, and infant formula. They noted that more microplastics were found in infants who had more than 600 ml of breastmilk a day than those who did not:

Underpinning the latter, the study results showed that microplastic abundance was higher in infants consuming more than 600 mL of breast milk per day compared to the children who did not. The researchers emphasized that their findings call for “investigating the contribution of plastic products to the microplastic exposure during the lactational period.”

Microplastics impair fetal growth

Zimmerman referenced a September 2022 article by Iranian researchers, published in the journal Environmental Pollution, who identified microplastics as responsible for intrauterine growth restriction (IUGR) pregnancies. As the counts of microplastics increased, the fetal weights and lengths decreased. 

Zimmerman shared the authors' concern that the microplastics might be affecting the nutrition available to the fetuses:

 According to the authors, this [sic] preliminary findin[g]s suggest that plastic particles might limit placental nutrient exchange. They emphasized that further research is needed to confirm these findings and to generally better understand the toxicological effects of microplastics during critical periods of life such as pregnancy in utero and early life.

X (formerly Twitter) user Zib Atkins reported on the most recent study published last month in Toxicological Sciences. According to the abstract, U.S. researchers found polyethylene, polyvinyl chloride, nylon, rayon, polystyrene, and other NMPs (nano- and micro-plastics) in the 62 placenta samples studied. 

The researchers developed special methodologies that enabled them to detect nano-plastics in fetal tissue:

We have developed methodologies to extract solid materials from human tissue samples by saponification and ultracentrifugation, allowing for highly specific and quantitative analysis of plastics by pyrolysis-gas chromatography and mass spectrometry (Py-GC-MS). As a benchmark, placenta tissue samples were analyzed using fluorescence microscopy and automated particle count, which demonstrated the presence of >1-micron particles and fibers, but not nano-sized plastic particles.

Together, these data demonstrate advancements in the unbiased quantitative resolution of Py-GC-MS applied to the identification and quantification of NMP species at the maternal-fetal interface. 

The authors expressed hope that these methods will be instrumental in discerning the adverse effects NMPs have on pregnancy outcomes. 

This method, paired with clinical metadata, will be pivotal to evaluating potential impacts of NMPs on adverse pregnancy outcomes.

How to avoid microplastics

Prospective parents, nursing mothers, and anyone concerned about their health should stop using NMPs as much as possible and detox them from their bodies. 

Cell Health News in its article Detoxing from Microplastics: Steps to Reduce Our Ingestion and Exposure suggests eating freshwater fish rather than saltwater fish or shellfish, eating fewer processed foods that come in plastic packaging, eliminating plastic water bottles, and avoiding makeup with glitter as some ways to mitigate exposure to microplastics.

In her article, I’m a Microplastics Researcher. Here’s How To Limit Their Dangers, author Laura López González includes suggestions from toxic chemicals researcher Tracey Woodruff, PhD, MPH about reducing toxic exposures. Woodruff suggested avoiding microwaving food in plastic containers and replacing non-stick cookware as measures to reduce microplastic exposure in one's household.

This video, 6 Tips How to Detox Microplastics, by Dr. Janine Bowring teaches how to remove the microplastics from your body: