Inconsistencies between endometrial receptivity assay and Adhesio-RT test for the window of implantation in women with repetitive failed donor oocyte embryo transfers.

Two commercially available second-generation endometrial receptivity assays using microarray analysis or next-generation sequencing are available in the market: endometrial receptivity assay (ERA) (Igenomix Laboratories) and Adhesio RT (OVO laboratories, Montreal, Canada). Little is known about how the results of these tests compare. We present a case of a subject with repetitive failed donor oocyte embryo transfer, who underwent evaluation of endometrial receptivity using both the Adhesio and ERA tests. These two tests did not provide consistent results, with ERA suggesting receptivity on day 5 of progesterone treatment and Adhesio suggesting receptivity on the eighth day. An ERA test subsequently performed on the eighth day of progesterone treatment was suggestive of post-receptive endometrium during the same time frame that Adhesio was suggestive of receptive endometrium. In conclusion, it is important to note that these two tests may not provide consistent results in at least some subjects. Therefore, intertest validity studies are recommended.