P-762 Discovery and quantification of microplastics in human cumulus granulosa cells

Abstract Study question The impact of microplastics (MPs) on human health has received increasing attention; their accumulation in female reproductive system and possible harms have not been quantified. Summary answer This study firstly reveals the contamination of human cumulus granulosa cells and follicular fluid by MPs and the effects of these contaminants on ART outcomes. What is known already MPs are ubiquitous in soil, sea, air, fresh water, and other environments. MPs are ingested by humans through the food chain, air and direct contact, resulting in various health problems, such as endocrine disruption, immune disturbance and reproductive toxicity. MPs exposure has been found to have a great impact on females, as MPs may accumulate in the ovaries and reduce the number of follicles, ovarian size, pregnancy rate, embryo production and fertility. To date, one study has found evidence of MPs in human placentas for the first time, but MPs contamination in other human reproductive systems has not been identified. Study design, size, duration The inclusion criteria comprised female patients of infertile couples excluding male factors who visited the outpatient department of the Reproductive and Genetic Hospital of CITIC-Xiangya between January 2019 and January 2021.We randomly selected 16 women who met the criteria and assessed their CCs and follicular fluid samples for the presence of MPs. Participants/materials, setting, methods In the present study, 16 cumulus granulosa cell samples and 2 follicular fluid samples were collected, and MPs were detected via pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Main results and the role of chance MPs were detected in both cumulus granulosa cells and follicular fluid, with an average abundance of 313.14±246.69 mg/kg in cumulus granulosa cellsand 12.88±15.54 mg/kg in follicular fluid. Polyethylene terephthalate was the predominant polymer in cumulus granulosa cells. There were no significant differences in the IVF fertilization rates, ICSI fertilization rates, IVF good-quality embryo rates, or ICSI good-quality embryo rates between the high-MP group and low-MP group. However, embryos in the high-MP group exhibited a lower normal cleavage rate than did those in the low-MP group, while the embryos in the high-MP group exhibited a greater proportion of noncleavage than did those in the low-MP group. Limitations, reasons for caution It is not clear how long these particles may persist in the human body. The method we used can detect only the concentration of MPs but not the size of MP particles. Moreover, our method cannot be used to quantify smaller-diameter nanoplastics, which are considered to pose greater risks. Wider implications of the findings This is the first study in which MPs were identified and characterized in human ovarian granulosa cells, providing reference data for evaluating their toxicity to the human female reproductive system. Trial registration number Not applicable