Haopeng Zhang, Xiaomeng Ding, H. Q. Zheng, Qianwen Ma, Ting Zhang
Microplastics (MPs) and nanoplastics (NPs) are emerging environmental contaminants that have raised increasing concern regarding their potential health effects. During pregnancy and early life, developing organisms are particularly vulnerable due to immature biological barriers and the dynamic nature of organogenesis. This review summarizes current evidence on maternal and early life exposure routes to MPs and NPs, including oral ingestion, inhalation, dermal contact, and transplacental transfer. Laboratory and epidemiological studies have demonstrated that microplastics can cross the placental barrier, potentially impairing placental function, altering fetal growth, and compromising pregnancy outcomes. Experimental data from animal models and in vitro systems suggest that maternal MP exposure may contribute to adverse neonatal development via multiple mechanisms including oxidative stress, inflammation, endocrine disruption, and epigenetic alterations. These toxicological pathways have been implicated in neurodevelopmental abnormalities, reproductive dysfunction, and immune dysregulation, often in a sex-dependent manner. Despite increasing experimental evidence, major knowledge gaps remain regarding human exposure levels, dose-response relationships, and long-term health implications. Future research should focus on improving detection sensitivity, establishing standardized exposure models, and developing targeted risk assessment frameworks to evaluate microplastic-associated health risks during pregnancy and early development.