International Non-selection Study for ERA® Test in Patients With Previous Implantation Failures

Women´s period comprises different hormonal stages, being one of them the stage for maximum receptivity and proper embryo implantation. This stage is named window of implantation (WOI), and is characterized by a specific molecular pattern than can be assessed by the Endometrial Receptivity Analysis (ERA® test), developed by Igenomix. Determining the WOI allows to schedule a personalized embryo transfer (pET) when the endometrium is most receptive for the implantation. The main objective of the present study is to improve our knowledge on the endometrial factor in an infertile population with previous implantation failures. To do so, a diagnosis of the endometrial receptivity to determine the WOI (ERA®) and the microbiome (EMMA®) of each participant will be performed, assessing its impact on deferred embryo transfers in terms of reproductive outcomes. Participants will follow their previously programmed IVF/ICSI treatment and, only when one embryo with no major anomalies is reported by PGT-A (Preimplantation Genetic Testing for Aneuploidies), they will be asked to attend to the specific study visit for endometrial fluid and biopsy samples collection. These samples will be used to determine the patient's WOI (ERA®) and endometrial microbiome (EMMA®). The results of neither of the tests will be disclosed to the patient or the doctor, being only used for the study purpose. After this visit, the patient will follow the pre-established schedule for an embryo transfer and pregnancy assessment.