This proposed research is a single center, prospective, single-blinded, randomized controlled trial, designed to evaluate IVF pregnancy outcomes following endometrial injury in 254 patients with implantation failure. Patients will be identified during their work-up and treatment at Shady Grove Fertility Reproductive Science Center. Only Shady Grove patients are eligible for the study. The investigators hypothesize in patients with one or more previous failed day 5 blastocyst transfers, injury to the endometrium via endometrial biopsy will improve clinical pregnancy outcomes compared to controls.