So researchers are experimenting with seeral approaches that would allow them to ealuate embryos and transfer only the healthiest ones that are most likely to take up residence in the uterus.

• 同时研究人员也正在对几种方法进行实验，以便对胚胎进行评价并且只将最健康的、最有可能着床胚胎移植入子宫。