Exposure to ambient particulate matter and reproductive outcomes among women undergoing in vitro fertilization/intracytoplasmic sperm injection: A prospective cohort study in China.

Limited evidence is available regarding the association between ambient particulate matter exposure and reproductive outcomes in women undergoing in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatments. In this prospective cohort study, we included 1237 women who underwent IVF/ICSI procedures in Hubei, China, between 2018 and 2020. We performed multivariate regression models to estimate the associations between exposure to particulate matter with diameters of ≤ 2.5 microns (PM2.5), ≤ 10 microns (PM10), and 2.5-10 microns (PM2.5-10) and ten pregnancy outcomes: the number of mature oocytes, number of zygotes with two pronuclei, maturation rate, fertilization rate, cleavage rate, best-quality embryos rate, ovarian sensitivity index, implantation, clinical pregnancy, and live birth. We found that exposure to particulate matter was associated with declines in maturation rate and fertilization rate but showed no significant associations with clinical pregnancy outcomes. Specifically, each interquartile range increase in PM2.5 was associated with a 1.01 % (95 % CI: 0.17 %, 1.84 %) reduction in the maturation rate and a 1.42 % (95 % CI: 0.29 %, 2.55 %) decrease in the fertilization rate. These associations were particularly pronounced during the follicle maturation stage (from 10 days before oocyte retrieval to retrieval day). Our findings provide novel evidence that exposure to ambient particulate matter may adversely affect early reproductive outcomes among women undergoing IVF/ICSI.