Characterization of gene expression profile during the implantation phase in IVF cycles in endometrium of women with recurrent implantation failure

With the rapid development of assisted reproductive techniques (ART), the number and quality of embryos have been optimized, but the embryo implantation rate has not been significantly improved yet. Recurrent implantation failure (RIF), a condition that is typically diagnosed in patients who fail to achieve clinical pregnancy after having undergone at least 3 times of embryo transfers (including a total of ≥4 good-quality embryos), is a challenging problem in ART treatment. Previous studies about RIF are limited to clinical trials and the detection of limited biomarkers within peripheral blood, but few about gene expression within local endometrial tissue and RIF, the key factors involved in RIF remain unclear. Our study was designed with an aim to compare the gene expression profile of RIF women with that of healthy proven fertile controls to explore the influence factors of endometrial receptivity and the mechanisms of RIF. Two groups of 6 women were selected: women with RIF (n=3) and fertile control women (n=3). Patients were suffering from tubal obstruction (tubal obstruction factor on hydrosalpinx, salpingitis, etc. were excluded) or unexplained infertility. Women recruited in the RIF group had a history of implantation failure from at least three consecutive IVF attempts (including a total of ≥ 4 good-quality embryos). Specimens were obtained via pipe suction curettage from the patients on day LH + 7. Tissue samples were washed thoroughly with sterile normal saline to remove excess blood and mucous and then snap-frozen in liquid nitrogen for microarray analysis.