long-term frozen storage of ovarian tissue for oncology patientsBackground Information
At birth the normal ovary contains a large number of eggs. After birth the number of eggs remaining in the ovary declines (falls) because no new eggs form. Women enter menopause when there are no viable eggs left in the ovary (usually around 50-55 years of age). Menopause can affect younger women if, for any reason, the number of remaining eggs is depleted faster than usual. As the ovary is the only source of egg cells, menopause also occurs when the ovaries are removed (ovariectomy).
Ovarian tissue function can also be affected by some forms of chemotherapy or radiotherapy, rendering the patient sub fertile or infertile. You can ask to have ovarian tissue collected and stored (at a low sub-zero temperature). This stored material may be thawed at a later date and re-grafted. This may help establish a pregnancy.
Long-term frozen storage and grafting of ovarian tissue have been effective for all animal models on which it has been tested. Grafts with frozen-thawed sheep ovarian tissue to six previously ovariectomised sheep restored normal hormonal cycles and allowed normal conception and term pregnancy (a healthy lamb) in one sheep. Other animal species (mouse, rat, rabbit) have also had their cycles and fertility restored by grafts of frozen-thawed ovarian tissue.
Data seen in the literature does note that in some forms of cancer (eg ovarian cancer), it is possible that the cancer cells will be present in the ovarian tissue and may re-establish within the body if the tissue is grafted.
We do not know yet whether frozen-thawed human ovarian tissue grafts will restore regular menses or allow natural conception and pregnancy in the human. At present, there is no genuine clinical protocol available for the return of tissue. Research still continues in this area.
Methods
The surgeon will collect some of your ovarian tissue under general anaesthesia. The piece of tissue collected by the surgeon will be placed in anti-freeze compounds and cooled to low sub-zero temperatures (at or below -196oC). The tissue will be stored in liquid nitrogen until it is required. It will then be thawed and replaced under general anaesthesia.
Risks
The risks associated with an ovarian biopsy are small and the removal of a small piece of ovarian tissue is not known to reduce a woman's reproductive potential. Women who are having an ovariectomy will need to discuss hormone replacement therapies with their doctor.
Confidentiality
The ovarian tissue will be stored for your own use only.
Contact Number
Should you have any concerns at any time about your participation in this project, please call Dr Tiki Osianlis on 9590 8355.
Consent Form
Signing the consent form indicates that you agree that, while you are under general anaesthetic, the surgeon may remove a small amount of your ovarian tissue, which will be frozen and kept for your own later use.
Fees
Monash IVF charges a fee for the freezing of ovarian material and there is an ovarian tissue storage fee billed twice a year in January and July for every year your ovarian tissue is in storage.
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