fertility preservation options for cancer patients

Oncology patients have several options to preserve their fertility: cryopreservation of ovarian tissue, vitrification of eggs and preservation of embryos. The choice of one technique or another will depend on the age of the patient and the limitations of her oncological treatment:

• Adult women: Women past puberty will be able to freeze their eggs after ovarian stimulation. The freezing of embryos requires the fertilization of the eggs with the partner's sperm or a sperm donor. The woman may undergo an in vitro fertilization cycle and cryopreserve the embryos created in the laboratory. These two techniques present a standardized protocol that is applied to patients who want to preserve their fertility, as well as to couples who undergo assisted reproduction cycles. The survival of eggs and embryos after thawing is high, which ensures the preservation of fertility during the time necessary for the patient to recover after cancer treatment.
• Girls who have not reached puberty: In the case of prepubescent girls, they are not yet in their fertile stage. Therefore, they cannot be stimulated to create a sufficient number of mature eggs to be cryopreserved. The technique used with these oncological patients is the preservation of the ovarian tissue, where the primordial and primary follicles, precursors of the eggs, can be frozen. Once the cancer treatment has been overcome and adulthood has been reached, the patient will be able to graft the ovarian tissue again and restore its ovarian function. This technique is still in the experimental phase, but the first pregnancies with ovarian bark transplant have already been obtained and it promises to be a hopeful technique for all those girls who have been detected with cancer in their childhood.

The technique of cryopreservation of the ovarian cortex also has application in those adult women with cancer who cannot undergo ovarian stimulation treatments before their cancer treatment, or the hormonal stimulation would worsen the state of their disease.