In vitro maturation (IVM) aims at achieving the final maturation of eggs within the laboratory with ultimate target their optimal fertilization. The immature eggs are obtained by puncturing follicles of small diameter. A similar method involves in vitro maturation of primordial follicles derived from frozen-thawed strips of ovarian tissue, in order to isolate and mature the enclosed oocytes.

In the first method (IVM), maturation only takes a few days, while the second (primordial follicle growth) requires special systems of extended culture. In both cases, the ultimate goal is the production of fully mature fertilizable eggs.

The method is quite promising in the field of ART, especially for special groups of women (e.g. women wishing to secure their fertility potential at a young age by freezing ovarian tissue for use later in life).

For now, the method is still at an experimental stage and its efficacy is limited. The main interests of IVM research groups are the enhancement of collection of immature egg from small follicles, improvement of culture conditions and guarantee that in vitro matured eggs are healthy and normal.