Cryopreservation and transplantation of ovarian tissue
The method intends to preserve a woman's reproductive ability prior to aggressive treatments for malignant conditions, aiming to restore normal ovarian function in the future.
A small part of the ovary which contains several immature follicles is removed by laparoscopic surgery or laparotomy and is frozen in Cryopreservation banks.
This confers the following future prospects:
- In vitro maturation of primordial follicles and immature oocytes until they reach the stage of full maturity and are able to be fertilized by IVF.
- Autografting, i.e. transplantation of the tissue in the same woman in order to restore her ovarian function.
- Heterografting, i.e. transplantation of the tissue in another woman who has lost her reproductive ability.
Freezing of ovarian tissue is internationally accepted, but restoration of ovarian function following transplantation is still under investigation. Progress is continuous giving hope to young cancer patients, who may wish to have a child later on in life.
Transplantation of ovarian tissue
A piece of frozen ovarian tissue can be transplanted in the body of the woman from whom it was taken (autografting) after total treatment from a malignant condition.
When the location of transplantation is the anatomic location of the ovary the transplantation is termed orthotopic. If the tissue is replaced in a different part of the body the transplantation is termed heterotopic. In heterotopc transplantation the ovarian tissue can be grafted in a more convenient anatomic position (e.g. under the skin) which facilitates oocyte recovery from follicles developing under drug stimulation
Experimental data have shown restoration of ovarian function for a limited period. Researchers investigate the factors that are responsible for the re-establishment of the function of the transplanted ovarian tissue and the restoration of the woman?s reproductive ability. Autologous and heterologous transplantation is only recommended in special cases after the approval of specialized scientists.