Abstract: In vitro maturation (IVM) refers to the maturation of immature oocytes at different stages. Immature oocytes obtained in different origins have different subsequent embryonic development capacity and pregnancy rates as well health live births rates. IVM as an efficient treatment has been used in those patients with polycystic ovary syndrome, ovary high response or low response, and fertility preservation. Several thousands of healthy IVM babies have been born in the world. The improvement of clinical IVM technology  focuses on IVM medium, the optimization of the culture environment and operation process. With the improvement of IVF efficiency and IVM culture system, the new treatment option was proposed that the combination of natural cycle/mild stimulation IVF treatment with immature oocyte retrieval and the followed IVM. This IVF combined with IVM may represent a viable alternative to the present standard treatment, or as a potential first-line treatment in future.

Key words: Oocytes, Cell culture techniques, Reproductive technologies, assisted, Fertilization in vitro