Ovarian Tissue Cryopreservation

Ovarian tissue cryopreservation and transplantation have been considered as promising means of fertility preservation for women diagnosed with cancer, with live births being reported from this technique. Ovarian tissue cryopreservation can be offered to patients with different types of cancer. Advances in chemotherapy and radiotherapy have increased the survival rate of cancer patients amazingly for young cancer patients. Increased life span raises concerns about the quality of life after treatment of cancer. Having children may be difficult for cancer survivors as both radio- and chemotherapies have been proven to be toxic to the ovaries. Recovery of ovarian function after anticancer treatment is very much affected by the loss of eggs due to chemo- or radiotherapy, resulting in a condition called premature ovarian failure (POF) and consequently, infertility in many female cancer survivors. Fertility preservation before treatment of cancer is an important option nowadays to overcome infertility induced by cancer itself or by the treatment to cure cancer.

The Fertility of female cancer patients could be preserved by various means such as egg freezing, embryo freezing or ovarian tissue freezing. Ovarian tissue freezing may be beneficial in patients with limited time between diagnosis and treatment since assisted reproduction (AR) is time-consuming. Secondly, prepubertal girls cannot undergo AR. Thirdly, ovarian stimulation using hormonal injections like gonadotropins may not be suitable for estrogen-sensitive cancers. The Ovarian cortex (outer layer of the ovary where eggs are found) can be obtained from any female cancer patient irrespective of age and marital status with no procedural delays in cancer treatment. Studies have shown that ovarian functions are well preserved in cryopreserved ovarian tissue.

Indications:

Patients diagnosed with any kind of cancer should be offered ovarian tissue cryopreservation before radio- or chemotherapy

Patients undergoing bone marrow or stem cell transplantation because of the high doses of radio- or chemotherapy carried out before transplantation which results in ovarian failure

Also, patients suffering from noncancerous disorders such as Turner’s syndrome as these patients will have non-functional ovary

CORTICAL OVARIAN TISSUE CRYOPRESERVATION: The outer layer of the ovary known as the ovarian cortex contains multiple growing follicles. Therefore, only the ovarian cortex is required for ovarian tissue cryopreservation. the Ovarian cortex may be obtained using different surgical techniques like laparoscopy or laparotomy.

WHOLE OVARY CRYOPRESERVATION: Another option is to remove the whole ovary and trans positioning it in a site out of the radiation field.

Ovarian Transplantation: Once the ovarian tissue is defrosted, it should be immediately transplanted. There are 2 techniques of ovarian transplantation:

Orthotopic – In the pelvis, Ovarian cortical pieces are transplanted retroperitoneally or in the pre-existing menopausal ovary

Heterotopic – Ovarian tissue implanted in the subcutaneous tissue of the forearm.

So far, many pregnancies have been reported after successful ovarian tissue transplantation