Synchrony between the timing of embryo transfer and the timing of a patient’s window of implantation (which has been shown to vary between women) play an important role in a successful transplantation. Meanwhile, about 25.9%-40% of the population with repeated implantation failures have displacements in their implant window. According to the conventional transplantation plan, embryos cannot be accurately implanted in the implant window, resulting in implantation failure. Endometrial receptivity test (YK-ERT®) can accurately determine the implantation window, optimize the embryo transfer time, assist patients with repeated implantation failures to improve the likelihood of a successful implantation, and avoid embryo waste.