ABSTRACT

Human reproduction is inefficient, as evidenced by a mean delivery rate of 37.3% per fresh embryo transfer in the U.S.A. in 2013 (1). Despite advances in assisted reproductive technologies over the past four decades, patients remain who fail to achieve live births following multiple in vitro fertilization (IVF)/embryo transfer cycles. Although delivery rates have improved, in the majority of failed implantation cycles, no identifiable etiology is found. Thus, isolating a specific cause for repeated implantation failure can be challenging. Patient age, genetic constitution of embryos, culture conditions, and endometrial receptivity have all been implicated in recurrent implantation failure (RIF).