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

Abstract

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.

Maternal exposure to polystyrene nanoplastics impacts developmental milestones and brain structure in mouse offspring

“…S1†). The significant growth restriction our group observed previously in late gestation fetuses exposed to NPs 13 did not persist at this postnatal stage.…”

“…The NP concentration was selected based on our previous work. 13 The pups were not culled after birth. At P2 the pups were paw tattooed for identification.…”

“…12 Our group recently demonstrated that maternal exposure to environmentally-relevant concentrations of polystyrene microplastics and NPs resulted in signicant fetal growth restriction in late gestation. 13 Another interesting nding was that the umbilical cord length was signicantly shorter in the NP-exposed group compared to controls. Short umbilical cords are associated with decreased fetal movements and potentially with abnormal fetal brain maturation.…”

Ingested Polystyrene Nanospheres Translocate to Placenta and Fetal Tissues in Pregnant Rats: Potential Health Implications

“…Altered fetal tissue macrophage function has been implicated in a number of neonatal and perinatal disorders, including hypoxic-ischemic encephalopathy (HIE), bronchopulmonary dysplasia (BPD) and necrotizing enterocolitis (NEC) [ 34 ]. In addition, several recently published studies have reported a variety of adverse effects on the fetus and progeny after oral exposure to polystyrene MNPs in pregnant mice, including metabolic disorders [ 27 , 28 ], hepatic and testicular toxicity [ 25 ], fetal growth restriction [ 24 ] and multiple developmental brain abnormalities accompanied by neurophysiological and cognitive deficits [ 23 ]. Further studies are needed to quantify the MNP concentrations and doses in the placenta and fetal organs as a function of time in a variety of exposure scenarios in order to assess the potential effects of the presence of MNPs in fetal tissues on fetal health and development, and to potentially mechanistically link the adverse effects observed in the offspring of rats exposed during pregnancy to the presence and specific locations of MNPs in fetal tissues.…”

“…However, the exposure routes responsible for the MNPs found in human tissues are not known, and given the aforementioned findings of intestinal MNP uptake and the current estimated human MNP ingestion rate, are most likely a combination of both ingestion and inhalation. Moreover, recent studies in experimental animals found that oral exposure to MNPs during pregnancy had multiple adverse effects on pregnancy outcomes and progeny [ 23 , 24 , 25 , 26 , 27 , 28 ], suggesting potential fetal translocation of the ingested MNPs. To date, however, no study has verified the translocation of ingested MNPs to the placenta or fetal tissues, which might account for those effects.…”