Cryopreservation of oocytes and spermatozoa

CRYOPRESERVATION OF OOCYTES AND SPERMATOZOA

Oocyte cryopreservation

An efficient cryopreservation program is an essential part of a multifunctional health care system that takes care of the future quality of life of patients.

Cryopreservation of oocytes offers an effective tool for the preservation of a woman's reproductive potential and allows pregnancy planning in different scenarios and social contexts and in relation to the choices and experiences of each individual woman.

To date, oocyte cryopreservation is recognized by international scientific societies as the method of choice to preserve the fertility of women in post-puberal age (The Practice Committees of the American Society for Reproductive Medicine and the Society for Assisted Reproductive Technology, 2013).

The reproductive potential of a woman can be compromised by oncological diseases, such as breast, ovarian and uterine cancer, systemic diseases or gynaecological diseases such as severe endometriosis, which, despite being a benign disease, can severely compromise the ovarian heritage. In addition, 1% of women may be exposed to a genetic risk of early menopause, which can occur before the age of 40.

Among the indications for oocyte cryopreservation for the preservation of female fertility are also personal reasons ("social freezing") which involve women who for various reasons (from professional to strictly economic ones) decide to postpone the search for a pregnancy.


The cryopreservation procedure. 

After oocyte harvesting, the mature oocytes obtained are cryopreserved using a technique called "vitrification". This is a validated method that allows the oocytes to be stored in liquid nitrogen at very low temperatures (-196°C) without causing any damage. This procedure is indicated as the "gold standard" among the methods of female fertility preservation (Rienzi et al., 2017).

 

Cryopreservation of spermatozoa

Cryopreservation of spermatozoa is a technique aimed at ensuring the self-preservation of male gametes for those patients who have to be treated with radio-chemotherapy that can irreversibly compromise the production of viable spermatozoa.

This technique can also be addressed to patients who have a severe alteration of seminal fluid parameters (severe oligoastenotheratospermia) to ensure the preservation of spermatozoa, in case of worsening of reproductive ability over time.

This technique also makes it possible to cryopreserve the sperm obtained surgically from the testicle or epididymis in order to avoid the patient having to undergo surgery for each assisted reproduction cycle faced.