New peer-reviewed research from AURORA scientists presents evidence that micro- and nanoplastics (MNPs) can cross the placental barrier and influence steroid hormone production. The findings raise concerns about potential effects during pregnancy and highlight the need for further investigation into how these particles may affect fetal development.
Published in the journal Molecular and Cellular Endocrinology on July 20, 2026, the study introduces a novel in vitro model consisting of three distinct cell lines: two representing the placental barrier and one representing fetal cells responsible for steroidogenesis, i.e., the process by which the body produces hormones. Using this model, the researchers examined whether MNPs can pass through the placental barrier and affect hormone production.
The results confirm findings from previous studies on the human placenta, showing that some MNPs can cross the placental barrier. Polystyrene (PS), polyvinylchloride (PVC), polymethyl methacrylate (PMMA), and polyethylene terephthalate (PET) were found to cross the placental barrier, while polyamide (PA) could not be reliably quantified. The researchers also found that some of the plastic particles tested altered hormone production. Polystyrene (PS), for example, primarily decreased estrogen levels, while other polymers predominantly reduced etiocholanolone (a metabolite produced from testosterone metabolism).
Although the study identified changes in hormone production, the researchers note that the exact mechanisms behind these effects remain unclear. Further research is also needed to better understand the potential implications for human development in the womb and the effects of longer-term MNP exposure.
According to lead author Dr. Jeske van Boxel, former AURORA researcher at Vrije Universiteit Amsterdam, “Our study shows that several types of micro- and nanoplastics can cross a human placental model and influence hormone production. While this does not directly mean they cause harm during pregnancy, it highlights the urgent need to better understand how these particles may affect fetal development.”
The study underscores the importance of continued research into the health impacts of MNPs, particularly during critical stages of early human development.
Reference
Van Boxel et al. (2026) Effects of different micro- and nanoplastic polymers on steroidogenesis in a feto-placental in vitro model. Molecular and Cellular Endocrinology. DOI: 10.1016/j.mce.2026.112871
