Ovarian Tissue Cryopreservation will be provided to cancer patients to allow them to have their fertility preserved.

This project hopes to provide Ovarian Tissue Cryopreservation to patients who do not have adequate time for ovarian stimulation in oocyte or embryo freezing and in prepubertal girls where oocyte freezing is not possible. All the patients will have fertility preservation consultations with a fertility specialist in our unit to go through the details of ovarian Tissue Cryopreservation service and risks related to ovarian tissue cryopreservation procedures. After undergoing ovarian tissue collection via surgery, the collected ovarian tissue will be cryopreserved either by slow freezing or vitrification in our unit.

Inclusion Criteria:

• Patients aged from 0-35 years old and diagnosed with cancer e.g., leukaemia, myeloproliferative or myelodysplastic diseases, lymphoma, bone tumours, neurological neoplasms and sarcoma, Paediatric bone marrow transplant patients
• Patients with any illness or who will undergo any type of treatment that may cause irreversible damage to their fertility, such as extensive abdominal surgery, high toxicity medication and treatments;
• Patients suffering from hormone-sensitive malignancies who will undergo medical treatment, such as radiotherapy and chemotherapy that is liable to damage their ovaries and deter them from conception in the future.

Exclusion Criteria:

• Patients with no anticipated oncologic therapies
• Patients who are pregnant
• Children with one ovary
• Children deemed high risk for perioperative complications
• Patients unable to provide consent/assent (i.e. significant psychiatric problems/cognitive delay)