Microplastics in Human Placentas Linked to Premature Births

A new study presented as part of the annual Society for Maternal-Fetal Medicine meeting has revealed a link between microplastic bioaccumulation in the human placenta to preterm, or premature, births.

In the study, researchers analyzed 175 placentas collected at both term and preterm, or under 37 weeks of pregnancy, and measured the amounts of 12 different microplastics and nanoplastics, including polyethylene (PE), polyvinyl chloride (PVC), polyurethane (PU) and polyethylene terephthalate (PET), using highly sensitive mass spectrometry.

The results showed that preterm placentas had much higher levels of polycarbonate (PC), PVC and nylon 66 (N66) compared to placentas from term pregnancies. The findings suggested that despite shorter gestation periods, the placentas in preterm scenarios with higher levels of microplastics were accumulating those microplastics earlier in the gestation period.

“The finding of higher placental concentrations among preterm births was surprising because it was counterintuitive to what you might expect if it was merely a byproduct of the length of time of the pregnancy,” said Dr. Enrico Barrozo, lead author of the study and an assistant professor in the Department of Obstetrics and Gynecology at Baylor College of Medicine and Texas Children’s Hospital in Houston.

While microplastics in the placenta have not been named as a cause of preterm births in the study, the researchers noted that the association warrants further research to better understand potential impacts on reproductive health. 

In the study, the research team determined that microplastic levels in the placentas were nearly 122 times higher than the amount of microplastics that have been previously detected in human blood.

“Our study hints at the possibility that the accumulation of plastics could be contributing to the occurrence of preterm birth,” said Dr. Kjersti Aagaard, senior author of the study, the Gulf Coast Division medical director and maternal-fetal medicine physician at HCA Healthcare and research professor at Boston Children’s Hospital, as reported by The Guardian. “Combined with other recent research, this study adds to the growing body of evidence that demonstrates a real risk from exposure to plastics on human health and disease.”

In addition to the link between microplastics and preterm births, another study published in 2024 revealed that one in 10 premature births in the U.S. could be linked to parental exposure to phthalates, chemicals commonly used in plastic production to make plastics more flexible.

More and more studies are unveiling risks of microplastics, especially in regard to how they can accumulate in human and animal bodies. In a separate study published this month, researchers found that microplastics ingested by mice were blocking the blood vessels and blood flow in the animals’ brains. While the researchers of that study noted that human and mice brains are different enough that the findings cannot conclusively be applied to humans, they did raise concerns over how microplastics could be impacting our brains.

Microplastics have also been detected in human testicular tissue, blood and lungs, but researchers are still working to understand how these chemicals can affect our health. 

In the meantime, there are ways to reduce microplastic exposure, including by not microwaving food in plastic containers, filtering drinking water, limiting seafood consumption and avoiding plastics containing phthalates.