In vitro maturation of oocytes (IVM): historical landmarks, current status and future perspectives

One of the major advancements in in vitro fertilization (IVF) has been the development of culture media that enhance gamete maturation in vitro and sustain embryo development up to the blastocyst stage. The deep understanding of the mechanisms involved in gametogenesis and the complex sequence of events surrounding nuclear and cytoplasmic maturation has also enabled the development of efficient in vitro maturation (IVM) protocols. This review outlines the major landmarks in the history of in vitro maturation of oocytes, the advantages and importance of its clinical application in human, especially in patients with Polycystic Ovary Syndrome (PCOS), Resistant Ovary Syndrome, high antral follicle count or oncology patients, as well as the safety and efficacy of the technique. IVM has not been shown yet to be as effective as controlled ovarian stimulation in terms of maturation rates, fertilization rates, and clinical outcome, possibly owing to a dysfunctional or asynchronous nuclear/cytoplasmic maturation process. A confusing set of IVM clinical protocols may also have contributed to the slow incorporation of the technology into routine IVF practice. However, recent improvements have led to comparable live birth rates between IVM and IVF, in women with high antral follicle count. The current status of IVM in the Assisted Reproductive Technology (ART) laboratory and its future perspectives, aiming to provide maximum fertility care to patients will be discussed.