[In vitro folliculogenesis: a woman is not a mouse!]

The informations obtained using in vitro folliculogenesis in rodents have shown that ovulation of preantral follicles or granulosa-cumulus complexes can be obtained after a few days of in vitro culture and that live young can be obtained following fertilization and development of these oocytes. In addition, initiation of follicular growth from primordial follicles could be achieved in organ culture in vitro. Hence, when the two techniques were combined, all folliculogenesis (from the primordial stage to ovulation) could be achieved in vitro. The situation is more complex in primates/human owing to the lower number of follicles initiating growth per day and to the longer duration of folliculogenesis. A few reports suggest that preantral follicles can survive and grow in culture for a few days and one study demonstrates that in 2 months, follicles can grow from 150 microns to 1.6 mm in diameter. The short term interest of such studies is to improve our understanding of the mechanisms involved in basal folliculogenesis. In the longer term, such techniques may prove useful to maintain some reproductive potential to women submitted to total body irradiation, to improve the management of reproduction of women suffering from early menopause or to generate oocyte banks to donate oocytes.