Liquid Crystal Monomers and Their Perturbations in Transplacental Transfer: Potential Impacts on Maternal-Offspring Health.
Liquid crystal monomers (LCMs), essential components of electronic displays, have been found in environmental and human samples due to their noncovalent integration and extensive use. Global liquid crystal display (LCD) panel production rose from 192 million m2 in 2017 to 450 million m2 by 2025, driving a greater environmental release of LCMs. Although LCMs exhibit endocrine-disrupting potential, information regarding their transplacental transfer and impacts on the reproduction and development remains largely unknown. Here, we compile the measured LCM concentrations in various maternal and fetal/offspring samples and examine their potential for transplacental transfer. Transfer may occur via passive diffusion, active transport, or placental sequestration, influenced by their chemical properties, tissue lipid profiles, and interactions with placental transporters. Available molecular docking studies on prevalent LCMs with key placental proteins are discussed to illustrate possible transporter-specific interactions, acknowledging the preliminary nature of these findings. We also compile human biomonitoring data and limited epidemiological studies alongside preclinical toxicology evidence from animal and in vitro models to assess their potential reproductive and developmental effects. Current evidence suggests that LCM exposure during pregnancy may pose risks to maternal-offspring health through mechanisms such as endocrine disruption, oxidative stress, altered intracellular signaling, and immune-inflammatory crosstalk. These findings underscore the need for mechanistic studies and regulatory attention to LCM exposure risks during pregnancy, offering insights into human exposure, transplacental transfer, and related toxicities.