Differences in the endometrial transcript profile during the receptive period between women who were refractory to implantation and those who achieved pregnancy.

Background: Gene expression profiling of normal receptive endometrium has been characterized, but intrinsic defects in endometrial gene expression associated with implantation failure have not been reported.

Methods: Women who had previously participated as recipients in oocyte donation cycles and repeatedly exhibited implantation failure (Group A, study group) or had at least one successful cycle (Group B, control group) and spontaneously fertile women (Group C, normal fertility group) were recruited. All were treated with exogenous estradiol and progesterone to induce an endometrial cycle, and an endometrial biopsy was taken on the seventh day of progesterone administration.