IRCT20160422027520N22 IRCT 2023-02-20 Tabriz University of Medical Sciences Investigating the effect of tacrolimus on fertility in women TPORIF The effects of Tacrolimus on pregnancy outcome in women with recurrent implantation failure (RIF) associated with immunologic factors: clinical trial 2023-03-01 anticipated 100 Complete https://irct.ir/trial/68614 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment, Randomization description: The method of random allocation will be with the help of a table of random numbers, and patients will be placed in one of two study groups based on the order of entry into the study and the results of random number calculations, Blinding description: The participants and the person who analyzed the results were blinded in this study. Participants were aware of the study before being randomized and informed consent was obtained from them. It should be noted that the person analyzing the results had no other role in this study. 2 Recurrent implantation failure. Intervention 1: Intervention group: According to the protocol, 1 to 2 mg of tacrolimus drug is administered orally to the study subjects daily, taking into account the level of immune system activity of the patients 2 days before the transfer and 14 days after the transfer. Intervention 2: Control group: receive no intervention. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is There is no more data