Maternal Exposure to Polystyrene Micro- and Nanoplastics Causes Fetal Growth Restriction in Mice

Plastics are ubiquitous and, when released into the environment, break down into smaller particles termed microplastics (MPs) and nanoplastics (NPs). These MPs and NPs can be ingested by organisms and potentially accumulate in tissues and organs. Recently, MPs were found in the placentas of healthy women, raising the concern that exposure to plastics may have an impact on pregnancy and fetal development. In this study, we investigated the effect of maternal exposure to plastics on fetal and placental growth using experimental mice. The dams exposed to plastics received either 5 μm or 50 nm polystyrene plastics in filtered drinking water at one of three concentrations (102, 104, or 106 ng/L). In late gestation, MP- and NP-exposed fetuses were significantly growth restricted, with a 12% decrease in fetal weight at the highest exposure concentration. This study represents a crucial first step toward evaluating the risks to human pregnancies posed by exposure to plastics.