Supplementary Material for: How to Reduce the Potential Harmful Effects of Light on Blastocyst Development during IVF

Purpose: Earlier findings revealed the damaging effect of visible light on zygotes and gametes. The aim of our study is to eliminate or significantly reduce the potentially harmful effects of light exposure during in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) and to investigate the effect of light protection on embryo development and implantation. Materials and Methods: To protect sperm cells, oocytes, and embryos from the potential harmful effects of light exposure during laboratory procedures, we created a dark environment for the cells and applied red filters on laboratory lamps and UV or infrared filters in the microscopes in order to eliminate white light exposure of the cells throughout all work stages. Results: The fertilization rate was significantly (p = 0.011) higher in light-protected ICSI cycles. Blastocyst development rates (blastocyst/embryo) were significantly (p < 0.001) higher in light-protected embryos than in those manipulated in conventional light conditions both in IVF (20.9% difference) and ICSI (38.6% difference). Numbers of clinical pregnancies/transfers of ICSI fertilized day 5 blastocysts were also significantly (p = 0.040) higher in light-protected conditions. Conclusions: These data show that light protection has a positive effect on fertilization rate and increases the blastocyst development as well as the number of clinical pregnancies/transfers. Implementation of this light protection method in IVF centers may improve the success rate while maintaining maximal embryo safety.

研究目的：既往研究已证实可见光可对合子与配子造成损伤。本研究旨在消除或显著减轻体外受精（In Vitro Fertilization, IVF）或卵胞浆内单精子注射（Intracytoplasmic Sperm Injection, ICSI）过程中光照暴露的潜在危害，并探究光照防护对胚胎发育与着床的影响。
材料与方法：为在实验室操作过程中保护精子细胞、卵母细胞及胚胎免受光照暴露的潜在危害，我们为细胞构建了避光环境，在实验室灯具加装红色滤光片，并在显微镜上配置紫外或红外滤光片，以确保全操作阶段细胞均不会暴露于白光之下。
研究结果：光照防护组的ICSI周期受精率显著更高（p=0.011）。相较于传统光照条件下操作的胚胎，光照防护组的囊胚发育率（囊胚数/胚胎数）在IVF（差异达20.9%）与ICSI（差异达38.6%）场景中均显著更高（p<0.001）。此外，ICSI受精后第5天囊胚的临床妊娠数与移植数在光照防护条件下同样显著更高（p=0.040）。
研究结论：本研究数据表明，光照防护可有效提升受精率，促进囊胚发育，并增加临床妊娠数与移植数。在IVF中心推广该光照防护方法，可在最大限度保障胚胎安全的同时提升辅助生殖成功率。