There are currently very few ova banks in existence.
Generally, the main purpose of storing ova, at present, is to overcome infertility which may arise at a later age, or due to a disease. The ova are generally collected between 31 and 35 years of age.
The procedure of collecting ova may or may not include ovarian hyperstimulation.
It can be expected however that ova collection will become more important in the future, i.e. for third party reproduction, and/or for producing stem cells, i.e. from unfertilized eggs (oocytes).