Fine particulate matter and its chemical constituents on oocyte quality in controlled ovarian hyperstimulation cycles: A prospective cohort study in China

Previous studies have examined the association between fine particulate matter (PM_2.5) and female oocyte quality; however, the specific chemical constituents influencing this association remain unclear. In this study, we examined the association between PM_2.5 constituents and oocyte quality in Hubei Province, China, using a generalized estimating equations model. We used a weighted quantile sum model to identify which PM_2.5 constituents most strongly impact oocyte quality. Our results showed that exposure to PM_2.5 constituents, including organic matter, black carbon, nitrate, sulfate, and ammonium, was associated with a decreased count of MII oocytes, 2PN oocytes, best cleavage-stage embryos, and increased rates of maturation failure and fertilization failure. Nitrate and organic matter demonstrated the strongest associations compared to the other constituents analysed. The most susceptible exposure windows differed depending on the reproductive outcomes measured, suggesting that different stages of follicular development exhibit differing sensitivities to PM_2.5 exposures. These findings highlight the importance of reducing secondary aerosol precursor emissions, particularly those from fossil fuel combustion and biomass burning.