**Abstract**

Retrieval of immature oocytes from non-stimulated ovaries, followed by in vitro maturation (IVM), was initially proposed in order to avoid side effects of gonadotropin administration. The goal is to eradicate or significantly decrease the risk of ovarian hyperstimulation syndrome (OHSS) in patients with polycystic ovary syndrome (PCOS) and to reduce drug cost and burden of patients. This technology was also proposed for treatment of normal ovulatory women, fertility preservation, or infrequent conditions as failure of oocyte to mature or repeated development of poor-quality embryos. There is no downregulation, and only a small amount of hormones are injected if at all. In vitro maturation of the oocyte procedure obtained up to 35% clinical pregnancy rate in young women, compared with in vitro fertilization (IVF) in many programs. The obstetric and perinatal outcomes of IVM cycles are comparable with IVF/ICSI cycles; therefore it may gradually substitute IVF in certain cases, as the technique continues to develop and pregnancy rates continue to increase. IVM holds great promises as an alternative to assisted reproductive technologies and may be the procedure of choice not only for infertile patients but also for obtaining oocytes for donation or fertility preservation.

**Keywords:** in vitro fertilization, in vitro oocyte maturation, oocytes, fertilized ovum, pregnancy outcome, pregnancy rates, reproductive techniques
