Accumulation of fibrosis and altered perifollicular stromal differentiation in vitrified-thawed human ovarian tissue xenografted to nude mice.

Fibrosis, reduced cortical stroma, and activation of dormant follicles were concomitantly observed in grafted ovarian cortex, which may relate to limited longevity. Perifollicular aSMA expression can be regarded as a marker of the competence of cortical stroma that regulate follicular development.