Nowadays, cancer treatments have improved and increased the life expectancy of cancer patients. When a young woman, who wishes to have her own offspring, has to undergo one of these treatments, she should be informed about the possibilities that this wish may not be fulfilled.
As has been done with semen samples for many years, now, with the appropriate technology and knowledge, new strategies have been developed to preserve the reproductive capacity of women undergoing cancer treatment.
Oocyte cryopreservation
Oocyte cryopreservation by vitrification is a validated technique in most laboratories, achieving survival and pregnancy rates quite close to those obtained with fresh oocytes, generally ranging between 30-45%. For all these reasons it could be considered one of the strategies of choice for preserving fertility in women diagnosed with different oncological processes.
At present we could say that in patients undergoing assisted reproduction techniques to preserve their fertility due to cancer, similar results are obtained as in infertile patients.
The fact of preserving oocytes or embryos will depend on the age of the patient (only applicable if they have reached reproductive age), the will of the patient, the existence or not of a partner at the time of the diagnosis of the disease and the ethical and legal considerations (generation of embryos).
It must always be taken into account that there must be a good ovarian reserve when we consider the option of cryopreserving oocytes/embryos, and for this reason it is essential to perform at least a gynecological ultrasound in order to be able to carry out this evaluation. Oocyte vitrification will be considered a good option to preserve the fertility of these patients if we obtain a minimum number of 10-12 oocytes, and we should even offer the maximum number of cycles possible prior to the start of chemotherapy.
Obtaining oocytes
In order to obtain oocytes/embryos, an average of 14 days of treatment is required prior to the start of chemotherapy, so it is essential to discuss with the patient the option of preserving her fertility from the first moment of diagnosis, as this could delay the start of cancer treatment.
Controlled ovarian stimulation to obtain oocytes/embryos can be initiated at any time during the menstrual cycle, requiring periodic analytical and ultrasound controls.
The oocytes are obtained through an intervention called follicular puncture, which is usually performed on an outpatient basis. It is performed under ultrasound guidance and sedation, and there should not be any medical contraindication for the performance of the procedure. Subsequently, the patient is discharged a few hours later, after the relevant assessment of the medical team.
Once obtained, the mature oocytes will be vitrified after evaluation in the laboratory, or they will be inseminated with the couple’s sperm, if the patient has chosen to freeze embryos, and finally these will be cryopreserved.