Investigations into implantation failure in oocyte-donation recipients

In recent decades, the Western world has been experiencing a societal trend to prioritize the professional careers of women who postpone motherhood to about 40 years of age, when, unfortunately, natural reproductive potential declines. This is the reason why these women increasingly find it necessary to resort to oocyte donation to have a child. Thanks to the young age of the donors, the efficacy of oocyte donation is the highest of all assisted reproduction treatments and pregnancy rates achieved with this technique exceed 50%. Moreover, the large registries from ESHRE and ASRM show live birth rates close to this figure. However, there are patients who experience repeated failures in several oocyte-donation cycles, and so far oocyte-donation repeated implantation failure has not been clearly defined. This study analysed the results obtained from 2531 oocyte-donation cycles carried out in 1990 patients and defines oocyte-donation repeated implantation failure as failure to implant with more than two embryo transfers and more than four high-grade embryos transferred. This study observed this condition in 140 oocyte recipients (7%). Also, oocyte cohort size, uterine factors and systemic thrombophilias as important aetiological factors were identified were to offer new therapeutic strategies to patients.Due to the social trend common in Western society of postponing motherhood to about the age of 40, there is an increasing demand for oocyte donation to circumvent the poor reproductive potential of women at this age. Oocyte donation is very efficient and pregnancy rates greater than 50% are usually achieved, with live birth rates also close to this figure. Nevertheless, even with this technique that offers the highest pregnancy rate of all assisted reproduction treatments, some patients fail repeated attempts of oocyte donation. We consider oocyte-donation repeated implantation failure if an oocyte recipient has unsuccessfully had more than two embryo transfers and received more than four top-quality embryos. We have observed this condition in 7% of the 1990 recipients included in this study. These patients require specific diagnostic protocols including deep evaluation of the uterine cavity and systemic screening of coagulation disorders to rule out abnormalities and to find out the possible causes of repeated implantation failure after oocyte donation. We now have several therapeutic strategies to apply to this group of patients in order to help them to reach the appropriate pregnancy rate that they would normally have obtained.