Oocyte maturation in assisted reproductive techniques.

Human oocyte maturation is a long process during which nuclear maturation occurs resulting in germinal vesicle breakdown (transition from prophase I to metaphase II) and extrusion of the first polar body. During oocyte maturation, in parallel with nuclear maturation, a number of events take place in the oocyte cytoplasm that assist fertilization and early embryonic development. So far several attempts have been made to mature human oocytes in vitro. The main patient group to which in vitro maturation (IVM) has been applied is polycystic ovarian syndrome. In a concise review we present the techniques used for the IVM of oocytes and the role of hormones and growth factors in IVM and subsequent fertilization and early embryonic development.