Shanshan Wu1, Yunshan Zhang2, Xueqing Wu3, Guimin Hao4, Haiqin Ren5, Jiahui Qiu1, Yinfeng Zhang2, Xingyu Bi3, Aimin Yang4, Lina Bai5, Jichun Tan6. 1. Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, No. 39 Huaxiang Road, Tiexi District, Shenyang, Liaoning 110022, PR China; Key Laboratory of Reproductive Dysfunction Disease and Fertility Remodeling of Liaoning Province, PR China. 2. Tianjin Central Hospital of Obstetrics and Gynecology, Tianjin 300100, PR China. 3. Center of Reproductive Medicine, Children's Hospital of Shanxi and Women Health Center of Shanxi, Taiyuan, Shanxi 030013, PR China. 4. Department of Reproductive Medicine, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei 050000, PR China. 5. Jinghua Hospital, Shenyang, Liaoning 110022, PR China. 6. Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, No. 39 Huaxiang Road, Tiexi District, Shenyang, Liaoning 110022, PR China; Key Laboratory of Reproductive Dysfunction Disease and Fertility Remodeling of Liaoning Province, PR China. Electronic address: tjczjh@163.com.
Abstract
BACKGROUND: Exposure to ambient air pollution has been reported to be inversely correlated with human reproductive health. However, the results of previous studies exploring the association between air pollution and in vitro fertilization (IVF) outcomes are conflicting, and further research is needed to clarify this association. OBJECTIVES: This study aimed to investigate the associations between exposure to air pollutants and IVF outcomes. METHODS: We conducted a multicenter retrospective cohort study involving 20,835 patients from four cities in Northern China, contributing to 11,787 fresh embryo transfer cycles, 9050 freeze-all cycles, and 17,676 frozen-thawed embryo transfer (FET) cycles during 2014-2018. We calculated the daily average concentrations of six criteria air pollutants (PM2.5, PM10, O3, NO2, CO, and SO2) during different exposure windows in IVF treatment timeline using data from the air monitoring station nearest to the residential site as approximate individual exposure. Generalized estimation equation models were used to assess the association between air pollution exposure and IVF outcomes. RESULTS: Exposure to O3, NO2, and CO during most exposure windows in fresh embryo transfer cycles were correlated with lower possibilities of biochemical pregnancy, clinical pregnancy, and live birth. An inverse association of exposure to O3 and SO2 with pregnancy outcomes was observed in FET cycles. In addition, we found a significant association of exposure to air pollutants with a higher risk of ectopic pregnancy and lower oocyte yield. CONCLUSIONS: Our study provided large-scale human evidence of the association between air pollution and adverse human reproductive outcomes in the population opting for IVF. Thus, exposure to air pollutants in the population opting for IVF should be limited to improve treatment outcomes.
BACKGROUND: Exposure to ambient air pollution has been reported to be inversely correlated with human reproductive health. However, the results of previous studies exploring the association between air pollution and in vitro fertilization (IVF) outcomes are conflicting, and further research is needed to clarify this association. OBJECTIVES: This study aimed to investigate the associations between exposure to air pollutants and IVF outcomes. METHODS: We conducted a multicenter retrospective cohort study involving 20,835 patients from four cities in Northern China, contributing to 11,787 fresh embryo transfer cycles, 9050 freeze-all cycles, and 17,676 frozen-thawed embryo transfer (FET) cycles during 2014-2018. We calculated the daily average concentrations of six criteria air pollutants (PM2.5, PM10, O3, NO2, CO, and SO2) during different exposure windows in IVF treatment timeline using data from the air monitoring station nearest to the residential site as approximate individual exposure. Generalized estimation equation models were used to assess the association between air pollution exposure and IVF outcomes. RESULTS: Exposure to O3, NO2, and CO during most exposure windows in fresh embryo transfer cycles were correlated with lower possibilities of biochemical pregnancy, clinical pregnancy, and live birth. An inverse association of exposure to O3 and SO2 with pregnancy outcomes was observed in FET cycles. In addition, we found a significant association of exposure to air pollutants with a higher risk of ectopic pregnancy and lower oocyte yield. CONCLUSIONS: Our study provided large-scale human evidence of the association between air pollution and adverse human reproductive outcomes in the population opting for IVF. Thus, exposure to air pollutants in the population opting for IVF should be limited to improve treatment outcomes.