The vitrification of oocytes is a solidification process in which the oocytes are treated with cryoprotective substances and submerged in liquid nitrogen at a temperature of -196°C. The steps are the same as in an IVF cycle: stimulation of the ovary with hormones followed by aspiration of the oocytes. Then, instead of inseminating and fertilising these, they are vitrified (using the Cryotop method) and subsequently stored in liquid nitrogen.
This is recommended in numerous and very wide-ranging situations, but the common denominator is postponing insemination of the oocytes and/or pregnancy.
The oocytes can be kept cryopreserved for as long as the patient wants or needs them; there is no time limit on this.
VITRIFICATION FOR CANCER PATIENTS
The vitrification of oocytes for cancer patients will allow pregnancy to be postponed until the patient has recovered from the disease, with the same reproductive prognosis that she had when the oocytes were vitrified upon diagnosis. The patients who most frequently request treatment at IVI to preserve their fertility are women who have been diagnosed with breast cancer.
It is important to get information and/or advice on the options in terms of preserving fertility as soon as the diagnosis has been made and treatment with chemotherapy is considered.
When it comes to thinking about the vitrification of a cancer patient’s oocytes, there are several factors which we have to take into account, such as her age, her ovarian function and follicular reserve, the time available to us before chemotherapy is started, and whether or not we have authorisation from the oncologist. The reproductive prognosis will depend greatly on the number of oocytes which we succeed in vitrifying. While it is not possible to guarantee a pregnancy, there will be the possibility of trying to achieve this through IVF.