Polystyrene micro- and nanoplastics cause placental dysfunction in mice†

Area of Science:

• Environmental Health
• Toxicology
• Developmental Biology

Background:

• Maternal exposure to microplastics and nanoplastics is a growing concern.
• Previous studies indicate potential for fetal growth restriction in mice.

Purpose of the Study:

• To investigate placental and fetal hemodynamic responses to microplastic and nanoplastic exposure in mice.
• To assess the impact of particle size on these responses.

Main Methods:

• Healthy pregnant CD-1 mice were exposed to polystyrene microplastics (5 μm) or nanoplastics (50 nm) via drinking water throughout gestation.
• High-frequency ultrasound was used to measure placental and fetal hemodynamic parameters.
• Control groups received no plastic exposure.

Main Results:

• Both microplastic and nanoplastic exposure caused placental dysfunction, with effects dependent on particle size.
• Microplastic exposure increased umbilical artery blood flow by 48%, while nanoplastic exposure decreased it by 25%.
• Fetuses exposed to both particle types showed reduced middle cerebral artery pulsatility index, indicating fetal brain adaptation to hypoxia. Nanoplastic exposure showed more pronounced effects.

Conclusions:

• Placental dysfunction and fetal hypoxia markers were more severe with nanoplastic exposure.
• Nanoplastic exposure during pregnancy may disrupt fetal brain development, potentially impacting neurodevelopmental outcomes.
• Particle size is a critical factor in the adverse effects of plastic exposure on maternal-fetal hemodynamics.