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.
Tianjin Central Hospital of Obstetrics and Gynecology, Tianjin 300100, PR China.
Environ Int. 2021 Aug;153:106544. doi: 10.1016/j.envint.2021.106544. Epub 2021 Apr 2.
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.
This study aimed to investigate the associations between exposure to air pollutants and IVF outcomes.
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 (PM, PM, O, NO, CO, and SO) 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.
Exposure to O, NO, 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 O and SO 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.
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.
已有报道称，接触环境空气污染与人类生殖健康呈负相关。然而，此前研究探索空气污染与体外受精（IVF）结局之间的关联结果存在矛盾，需要进一步的研究来阐明这种关联。
本研究旨在调查污染物暴露与 IVF 结局之间的关联。
我们进行了一项多中心回顾性队列研究，纳入了来自中国北方四个城市的 20835 名患者，共涉及 11787 个新鲜胚胎移植周期、9050 个冻融周期和 17676 个冷冻胚胎移植（FET）周期，这些周期发生在 2014 年至 2018 年期间。我们使用距离居住地点最近的空气监测站的数据，计算了不同暴露窗口中 IVF 治疗时间线上六种标准空气污染物（PM10、PM2.5、O3、NO、CO 和 SO2）的日平均浓度，以此作为个体暴露的近似值。使用广义估计方程模型评估了空气污染暴露与 IVF 结局之间的关联。
在新鲜胚胎移植周期中，大多数暴露窗口下的 O3、NO 和 CO 暴露与生化妊娠、临床妊娠和活产的可能性降低有关。在 FET 周期中，O3 和 SO2 暴露与妊娠结局呈负相关。此外，我们还发现，暴露于空气污染物与异位妊娠风险增加和卵母细胞产量降低显著相关。
本研究为选择 IVF 的人群中空气污染与不良生殖结局之间的关联提供了大规模的人类证据。因此，应限制选择 IVF 的人群接触空气污染物，以改善治疗结局。
