Effects of Exposure to Micro- and Nanoplastics on Endometrial Injury and Adverse Pregnancy Outcomes: Evidence Integration Using the Targeted Risk Assessment of Environmental Chemicals Framework.

Micro- and nanoplastics (MNPs) are emerging environmental pollutants, but evidence concerning their effects on endometrial injury and adverse pregnancy outcomes remains limited. Therefore, we employed the Targeted Risk Assessment of Environmental Chemicals (TRAEC) strategy to integrate evidence concerning endometrial injury and adverse pregnancy outcomes associated with exposure to MNPs. Following targeted screening, 21 unique studies yielded 24 literature-derived evidence entries. Together with one additional in vitro evidence item from the present study, 25 evidence items were included in the final CES calculation. The available evidence was quantitatively integrated across four predefined TRAEC dimensions: Reliability Scores, Weight of Concentrations, Risk Intensity, and Correlation Scores. Under the tested in vitro conditions, exposure to PS-NPs increased intracellular ROS accumulation, reduced mitochondrial membrane potential, promoted apoptosis, and decreased the expression of key endometrial receptivity proteins, namely HOXA10, FOXO1, and ITGB3, in primary human endometrial stromal cells. Based on this combined evidence pool, the final Comprehensive Evidence Score was 7.67, corresponding to a preliminary moderate-risk classification within the predefined TRAEC framework. In summary, the TRAEC strategy provides a structured approach for integrating multi-level evidence and deriving a framework-specific health-risk classification for exposure to MNPs.