Quantile G-Computation (QG-C) regression analysis of mixture air pollution exposure’s impact on clinical pregnancy likelihood across various exposure periods. Using the QG-C model, after adjusting for age, BMI, stimulation protocol, endometrial thickness on hCG day, total dose of Gn, duration of infertility, cause of infertility, infertility type, number of retrieved oocytes, number of embryo transfer, stage of embryo transfer, temperature, and dew point, the relationship between the weights of each pollutant and the likelihood of clinical pregnancy was assessed across four distinct time periods: Period 1 (A), Period 2 (B), Period 3 (C), Period 4 (D). Period 1, 90 days before oocyte retrieval; Period 2, oocyte retrieval to embryo transfer; Period 3, embryo transfer to serum hCG test; Period 4, 90 days before oocyte retrieval to serum hCG test; Gn, gonadotropin; PM2.5, fine particulate matter (particles ≤ 2.5 µm); PM10, inhalable particulate matter (particles ≤ 10 µm); CO, carbon monoxide; NO2, nitrogen dioxide; O3, ozone; SO2, sulfur dioxide; ψ, logarithm of the odds ratio; OR, odds ratio.