Chapter 2 - Animal Models of Ovarian Transplantation

The field of ovarian cryopreservation has built on animal model studies carried out in the 1970s and 1980s using the sheep as a mono-ovulatory large mammal, with thus a comparable reproductive endocrine system, the opportunity to carry out human-relevant surgical procedures, and repeated blood sampling over a long period. This allowed proof of concept that ovarian cortical tissue could be removed, cryopreserved, and reimplanted onto the ovarian pedicle with subsequent reestablishment of ovarian cycles and indeed natural conception and successful pregnancy. These studies also identified many of the key findings that remain today, such as the loss of a large proportion of the primordial follicle pool after reimplantation. The potential for whole ovary transplantation continues to be investigated. Animal models have also been used for testing for malignant cells within the ovarian tissue, in the development of methods for in vitro follicle growth and oocyte maturation, and of artificial ovary systems.