Today we are sharing with you an ongoing clinical study. Embryos and endometrium are the two key factors affecting the success of IVF. For successful conception, good quality embryos and a well-tolerated endometrium are essential. In the past, it was believed that embryonic factors play a major role in the IVF process, but in recent years, the endometrial factor is gaining attention, and poor endometrial quality can reduce the success rate of IVF. In addition to the reduced tolerance of the endometrium to the embryo, poor endometrial quality may also be due to window period displacement. The window period is a very short period of time, about 6 to 10 days after ovulation, during which only the lining of the lining can allow embryo implantation, and the normal window period lasts about 1 to 2 days. Window period change Some studies have shown that 1 in 4 people with repeated failed implantation have a window period change, which is much higher than the normal population. Therefore, it is inferred that some of the people with recurrent bed failure may have failed to get laid due to window period shift. ERA – finding the window period Currently, the endometrium is assessed clinically mainly by diagnostic scraping and endometrial morphological manifestations such as thickness and trilinear signs under ultrasound, which still need to be improved and cannot determine whether the patient’s window period has changed. Based on this, a foreign scientific team designed an endometrial receptivity array (ERA) to detect endometrial receptivity, especially to diagnose the window period and guide transplantation, thus increasing the rate of implantation and pregnancy and improving IVF outcomes. The researchers designed the ERA by screening 238 genes based on the different gene expression in the human endometrium during different menstrual periods. the ERA can detect the biological activity status of the endometrium from the gene expression level to determine whether it is in the window period and thus guide the clinic. The team’s preliminary research has shown that individualized transfer guided by ERA can significantly improve embryo implantation rate and pregnancy rate of patients. The product is currently in clinical trials in several countries around the world and results will be available by the end of the year, which will hopefully improve IVF outcomes for patients who have failed to achieve implantation due to altered window periods with the help of ERA.