Cryopreservation of ovarian tissue

After a flurry of interest following the first successful attempts to cryopreserve ovarian tissue in the 1950s, the technique appeared to have no practical applications and was ignored for almost 40 years. Its potential for conserving fecundity is now being reassessed in the light of the growing numbers of young people who have been sterilized by successful cancer treatment, Ovarian tissue banking is, in theory, a practical alternative to oocyte storage, and avoids the ethical dilemmas of embryo storage. Under optimal conditions, primordial follicle survival rates in excess of 70% can be achieved. Experimental animal studies have shown that frozen-thawed tissue can restore fertility by orthotopic autografting, but this strategy is unsafe where there is a risk of malignant cells remaining in the stored tissue. In the long-term, therefore, it is hoped that frozen-thawed follicles can be grown in vitro to avoid any danger and extend the range of possibilities with this technique.