Fertility preservation program in women at risk
What does this program mean and who is it aimed at?
There are women who may prematurely lose their reproductive function due to poor ovary function that leads to a situation similar to menopause. There are many causes and circumstances that may produce premature menopause. Among these, ovarian surgery, genetic or autoimmune diseases and oncologic treatments such as chemo- and radiotherapy are of note.
What can be done in these cases?
There are several alternatives aimed at preserving the fertility of the patient for the future in these situations. When mature oocytes are obtained following hormone stimulation, cryopreservation of the embryos or only the oocytes may be carried out. If previous hormone stimulation has not been performed, the ovarian tissue itself may be directly cryopreserved.
How is embryos cryopreservation done?
This requires ovarian stimulation treatment that starts with the menstruation period and last from twelve to fourteen days. After this treatment, ovarian follicular puncture is performed to obtain oocytes and fertilise them. Thereafter, the embryos are cryopreserved. The results may vary depending on the response to treatment and the age of the woman but, on average, a rate of 30 % of pregnancy per cycle may be foreseen.
How is oocyte cryopreservation done?
It is the same treatment as in the previous case but, since an adequate masculine sample is not available, the oocytes are directly cryopreserved. When the conditions are appropriate, they may be fertilised in the laboratory and, if the process goes well, some of the embryos obtained will be transferred into the uterus of the patient. This technique is much newer; in fact, its efficacy has increased thanks to the latest technical advances. It is estimated that more than 100 children around the world have been born with the aid of this technique. In Spain, centres must have specific authorization from the public healthcare authorities in order to carry out oocyte cryopreservation treatments with reproductive goals. In 2007 our centre was authorized.
In what cases can hormone stimulation not be done?
Hormone stimulation cannot carry out when the conditions are not ideal or there is not enough time to carry out the complete process or there is some contraindication for performing ovarian stimulation. In this regard, it should be taken into account that, in certain oncologic diseases, it is not advisable to delay the initiation of chemotherapy and, in other cases, this hormone treatment may be contraindicated. Lastly, this stimulation should not be performed if the patient is very young and has not yet started her menstrual cycles. In all these cases, a last therapeutic option may be approached, that is, cryopreservation of ovarian tissue.
How is cryopreservation of ovarian tissue carried out?
The ovarian tissue cryopreservation is performed with a surgical intervention by laparoscopy in which a biopsy of the ovarian tissue is made and cryopreserved at the same time as the surgery. It may be carried out at any time during the cycle and does not require previous treatment. It does not delay the initiation of oncologic treatment and may be done in pre-puberty patients. At present, this is an experimental technique that can only be done in authorized and highly specialized centres and it is aimed at patients with a high risk of losing ovarian function or those in whom other conventional techniques cannot be performed. The results are promising. There have been achieved worldwide over 50 gestations thanks to this technique. It is essential that the patient be in good physical condition before undergoing the surgery. If the underlying disease involves the ovary, it is contraindicated.
How is the best alternative decided?
It is necessary to do an individualized study of each case, since factors such as the age, the predictive factors of ovarian response and the type and urgency of oncologic treatment to be received will determine the best alternative to preserve the patient’s fertility. In case of oncologic disease, decisions have to be made in consensus with the rest of the medical professionals who intervene in the clinical process of the patient.