Cumulative Live Birth Rates of 31,478 Untested Embryos From 11,463 Women Challenge Traditional Recurrent Implantation Failure Definitions

(Abstracted from Hum Reprod 2025;40(5):818–833) Pregnancy rates per embryo transfer in fresh cycles in Europe are approximately 34.6% for in vitro fertilization (IVF), 33.5% for intracytoplasmic sperm injection (ICSI), and 35.8% for frozen embryo transfer cycles; these rates make it clear that not every cycle results in the implantation of an embryo or a live birth, although success rates have been increasing in recent years. In light of this and of the complexity of infertility cases, it is important for clinicians to be able to distinguish when the repeated failure of implantation is problematic and when it is simply chance.