Gestational inhalation of nanoparticles disrupts placental zone structure and induces vascular placentation in rats

did not affect placental weight or efficiency, it reduced decidua and labyrinth zone size. Exposed placentas exhibited compensatory adaptations characterized by increased blood space number and maternal blood space expansion. Together, these findings indicate that inhalation of nanoparticles disrupts placental structure while simultaneously eliciting changes in vascular architecture that may preserve nutrient exchange capacity. By characterizing the effects of PM exposure on placental morphology and structure, this study highlights the placenta as a vulnerable target of inhaled pollutants and provides mechanistic insight into pathways contributing to PM-induced FGR.