Immature oocyte retrieval with in-vitro oocyte maturation

Early studies of in-vitro fertilization used immature oocytes. The process evolved to retrieving metaphase II oocytes, and was eventually successful. At present, aggressive ovulation induction protocols are the mainstay of as sisted reproductive technology programs, but not without increased cost, mu ltiple gestations, morbidity, potential future risks and isolated mortaliti es. The ability to retrieve each month's cohort of immature oocytes transva ginally opened the door to search for a new option for infertile couples re quiring assisted reproductive technology. Immature oocyte retrieval combine d with in-vitro oocyte maturation eliminates the stimulation, costs and tim e that were required to monitor oocytes, along with the short- and long-ter m complications. The essential components are optimal maturation media and a synchronized endometrium in which the embryos transferred from a truncate d follicular phase can implant. The process has been successful in several centers with an acceptable success rate when used in conjunction with a hos t uterus. Future research with maturation, culture, and endometrial synchro nization may allow immature oocyte retrieval with in-vitro oocyte maturatio n to replace in-vitro fertilization in its present form. (C) 1999 Lippincot t Williams & Wilkins.