Cryopreservation of spermatozoa
Methods of sperm cryopreservation
Currently there are two effective methods of sperm cryopreservation:
1). Slow freezing
After freezing, spermatozoa are stored in liquid nitrogen, where they remain inert as long as they are at minus 196°С. There is no evidence of additional risks of birth defects or chromosomal abnormalities following the use of cryopreserved sperm. It is a safe method of male gamete preservation.
Even though freezing-thawing leads to a slight loss of viability and mobility of spermatozoa, it does not have a negative effect on fertilization by the ICSI method. It was established that there is no difference in the frequency of pregnancy after ICSI when using fresh and frozen ejaculate.
Sperm cryopreservation revolutionized ART. The methods of conservation are constantly improving and the indications for carrying out are expanding. This method gives hope to men suffering from cancer for future parenthood. In addition, it allows to avoid additional surgeries for patients with obstructive azoospermia.
Cryopreservation of sperm is carried out according to various indications:
1). Absence of a male partner during the day oocyte puncture during egg fertilization.
2). Individual variability of sperm quality (extreme oligozoospermia) to accumulate a sufficient number of spermatozoa for fertilization.
3). Fertility preservation in men.
4). Patients with oncological diseases (before chemotherapy and radiotherapy, as these can cause loss of reproductive function).
5). During treatment with cytotoxic drugs.
6). Future surgical interventions of the testicles.
7). Avoid the transmission of diseases that can be transmitted through semen.
8). Creation of a “bank” of donor sperm.
Thus, cryopreservation of sperm cannot only increase the chances of conception in a married couple, but also save money after the success of the first IVF protocol, by freezing several portions of sperm and thickening it during thawing.