New study: Microplastics may cross placenta, affect hormone production

Micro and nanoplastics may be able to cross the placental barrier and impact steroid hormone production during pregnancy, according to a new study. As plastic production has surged since the 1950s, these persistent polymers have become ubiquitous in the environment, eventually breaking down into smaller particles that can enter the human body.

While concerns about microplastics are growing, scientific understanding of their health consequences remains limited. The study, led by researchers at Vrije Universiteit Amsterdam and published in Molecular and Cellular Endocrinology, indicates that certain micro and nanoplastic particles can penetrate the placental barrier and influence steroid hormone synthesis. Prior research has already detected micro- and nanoplastics in human blood, placentas, amniotic fluid, and meconium, with one study finding them in every analyzed human placenta.

The presence of these particles near the fetus is concerning because critical human structures form during early development, and any disruption could have serious consequences. However, it remains unclear whether plastic particles actually interfere with human fetal development. Animal studies have yielded mixed results, with some showing plastic fragments in fetal organs and others suggesting potential disruption of fetal brain development.

To better understand these potential effects during human pregnancy, researchers developed a new laboratory model of the human placenta. This model, composed of three layers of living human cells, mimics the protective barrier of the placenta. It incorporates BeWo b30 cells (epithelial tissue), HUVEC cells (from the umbilical cord vein), and H295R cells (from human adrenal glands). This innovative approach aims to provide a more accurate representation of the complex interactions between mother and fetus and the processes of steroid hormone production than previous models.