Detection and quantification of microplastics in endometrial polyps and their role in polyp formation

With the increasing use of plastics, microplastic (MPs) pollution has garnered significant attention in recent years. Endometrial polyps are prevalent gynecological conditions in women of childbearing age, which impair endometrial receptivity and contribute to female infertility. However, no studies have yet reported the exposure of endometrial polyps to MPs. This study employed pyrolysis-gas chromatography/mass spectrometry and laser direct infrared spectroscopy to detect and compare MPs between normal endometrium and endometrial polyps. Using Py-GC/MS, we identified three main MPs in 14 normal endometrial samples and 16 endometrial polyps. The average abundance of MPs in the endometrial polyp group was significantly higher than in the normal endometrium group. The respective average abundance of polyethylene (PE), polystyrene (PS), and polyvinyl chloride (PVC) in the polyp and normal endometrium groups was 13.66 ± 2.0 vs. 7.132 ± 0.78 μg/g (p = 0.0009), 94.81 ± 10.67 vs. 69.29 ± 6.93 μg/g, and 67.67 ± 11.02 vs. 56.35 ± 6.90 μg/g. LDIR analysis revealed 13 different types of MPs, with polymethylmethacrylate being the most prevalent. Moreover, we discovered that PS microspheres can promote the proliferation and migration of endometrial stromal cells through PI3K/AKT pathway, which may be a key factor in the formation of endometrial polyps. This study is the first to explore the presence of MPs in endometrial polyps, compare the differences in MPs content between normal endometrium and endometrial polyps, and clarify the potential connection between MPs exposure and the formation of endometrial polyps. Further research is required to explore additional potential insights.