IRCT2017073034422N2 IRCT 2017-10-16 Avicenna Research Institute Effects of Autologus Platelet- Rich Plasma on ICSI outcomes and Pregnancy Rate in frozen embryo transfer cycles in Repeated Implantation Failure Patients PRP in RIF in FET cycles Effects of Autologus Platelet- Rich Plasma on ICSI outcomes and Pregnancy Rate in frozen embryo transfer cycles in Repeated Implantation Failure Patients 2017-10-23 anticipated 60 Complete https://irct.ir/trial/26299 interventional Randomization: Randomized, Blinding: Single blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment. N/A Infertility, recurrent implantation failure. Intervention 1: In intervention group, PRP will be done for patient 48 hours before embryo transfer. For PRP, 8.5 cc of peripheral blood will be given and the number of platelet will be checked. Then the blood will be put in a space which has 2.5 cc special anti coagulant and centrifuged with 1200 rpm for 12 minutes. Then superior part of plasma will be separated and centrifuged with 3500 rpm for 6 minutes again. The platelet number will be checked again and if it becomes 4-5 times, 0.5 cc of this solution will be transferred into uterus cavity 48 hours before embryo transfer. Intervention 2: In control group, the embryo transfer catheter will be inserted for patient 48 hours before embryo transfer and will be removed without injection of anything.