Clinical factors affecting endometrial receptiveness in oocyte donation cycles.

OBJECTIVE: To provide a summary of the actual knowledge about the clinical factors affecting the oocyte recipient (other than those associated with uterine cavity abnormalities) on the outcome of oocyte donation cycles.
DESIGN: Review of the literature.
SETTING: Information regarding the association between age, body mass index (BMI), endometrial priming, tobacco consumption, hydrosalpinx, and endometriosis/adenomyosis in oocyte recipients and the results of oocyte donation cycles. RESULT(S): Recipient age and the presence of hydrosalpinx are clearly associated with a poorer outcome in oocyte donation cycles. The negative impact of tobacco consumption has recently been confirmed. The exact relevance of an elevated BMI is under debate but it is likely that it determines a lower ongoing pregnancy rate (PR). Endometriosis may be significant for endometrial receptiveness in the context of a natural cycle, but no negative impact is detected when standard endometrial priming protocols are used in oocyte donation. The same may be true for adenomyosis, although its relevance to endometrial receptiveness is less clear. CONCLUSION(S): Accumulated knowledge in the field of oocyte donation has led to the recognition of clinical variables that affect cycle outcome by impairing endometrial receptiveness. Many studies are being carried out on endometrial molecular and gene expression changes taking place in these circumstances. In the near future a comprehensive understanding of these processes should be achieved, from a genetic, molecular, and clinical perspective. These advances in the collective knowledge will lead to an improvement in the diagnosis and treatment of infertile patients.