BackgroundGlobally, air pollution has a significant impact on human health. However, the effects of air pollution on pregnancy outcomes in patients undergoing in vitro fertilization (IVF) have not been fully understood. In this study, we analyzed the effects of air pollution on IVF pregnancy outcomes in Taiyuan, which is a heavy polluted city in northern China.Methods516 patients who underwent first fresh IVF cycle were enrolled in the retrospective study from January 1, 2015 to May 31, 2020. We collected medical record data from the electronic medical record system and daily average air pollution data from air quality monitoring station. Logistic regression was used to analyze the relationship between six atmospheric pollutants (PM2.5, PM10, O3, NO2, SO2, CO) and air quality index (AQI) and IVF pregnancy outcomes (biochemical pregnancy and clinical pregnancy) in different exposure periods. ResultsThe results indicated that exposure to NO2 was negatively associated with the odds of biochemical pregnancy and clinical pregnancy, whereas exposure to O3 presented positive association. Furthermore, we also found that AQI was negatively associated with IVF pregnancy outcomes. ConclusionsOur findings suggested that exposure to ambient air pollution during any period may have an impact on IVF pregnancy outcomes, and poor air quality is more likely to reduce clinical pregnancy rates.