Association of atmospheric temperature and PM_2.5 co-exposure with embryonic development and pregnancy outcomes in...

To investigate the association between atmospheric temperature and embryonic development and pregnancy outcomes in women undergoing IVF/ICSI, and to evaluate the interaction between temperature and PM_2.5. This study included 3747 patients undergoing IVF/ICSI treatment at one tertiary hospital in Henan Province from January 2015 to August 2023. Daily mean temperature, relative humidity, and PM_2.5 concentrations were sourced from publicly available datasets. Temperature exposure was evaluated across seven time windows, with average levels calculated for each. Outcome measures encompassed oocyte and embryo quality indicators and pregnancy outcomes. Compared with the reference temperature range, exposure to low temperature dTimes New Romanuring Period C (from the start of gonadotropin treatment to oocyte retrieval) was associated with - 2.95 (95% CI: -5.72, -0.10)% decrease in the number of oofcytes retrieved. Exposure to high temperature during the same period was associated with - 5.39 (95% CI: -9.60, -0.98)% decrease in the number of high-quality embryos. High temperature exposure during Period C, D (from the start of gonadotropin treatment to embryo transfer), and E (from efmbryo transfer to HCG testing) was associated with decreased risk of live birth, with ORs (95% CI) of 0.46 (0.26, 0.79), 0.54 (0.31, 0.96), and 0.36 (0.21, 0.62), respectively. Combined exposure to high temperature and PM_2.5 during Period B was associated with decreased numbers of oocytes retrieved, cleaved embryos, and high-quality embryos. High and low temperatures can impair oocyte and embryo quality and pregnancy outcomes in IVF/ICSI patients, while combined exposure to high temperature and PM_2.5 may worsen these adverse effects.