Oocyte cryopreservation for elective preservation of reproductive potential

Two decades ago the first pregnancy achieved with a frozen thawed human oocyte was reported. This technique transformed the potential for fertilization of an oocyte from a 24-hour window to an unlimited number of years. This paper will review progress in this field including advances in freeze/thaw protocols, the addition of intracytoplasmic sperm injection, and improvements which have led to increased oocyte survival, fertilization, and live birth rates. We will review clinical scenarios in which this intervention is beneficial including: 1. women requiring treatments for benign or cancerous processes which diminish or destroy ovarian reserve 2. women who choose to delay childbearing for personal reasons 3. couples undergoing IVF cycles who prefer to freeze excess oocytes rather than embryos 4. flexibility in IVF cycles when sperm is not available 5. potential to create banks to allow couples seeking donor oocytes a wide selection of immediately available quarantined oocytes We will compare success with cryopreservation of individual oocytes vs. cryopreservation of ovarian tissue and the ethical and societal concerns with both techniques. Information will also be provided on perinatal outcome and follow up of children conceived from frozen oocytes.