Paffoni A, Palini S. There is another new method for cryopreserving small numbers of human sperm cells. Ann Transl Med. 2019 Mar; 7(Suppl 1): S17.
The manuscript by Berkovitz et al. (1), re-opens the debate on a niche, but important, issue in in vitro fertilization concerning the cryopreservation of a very small number of spermatozoa form an ejaculate or with a surgical origin.
A small but not negligible percentage of infertile subjects can benefit from an efficient program of cryopreservation of the few available sperms because:
(I) it can prevent the execution of repeated testicular biopsies in the azoospermic patient
(II) it may limit the risk of being without sperm on the day of in vitro fertilization;
(III) it eliminates the issues associated with the coordination of the women’s oocyte retrieval with the surgical sperm retrieval.
For these reasons several technical strategies have been proposed over time with the intent of cryopreserving spermatozoa ensuring good survival, easy recovery and fertilization potential at thawing and limiting in the meantime the sperm loss [see Table 1 and the review (13)].
However, due to limited efficiency and various shortcomings, none of these methods has been chosen by a preponderant portion of laboratories to become the method of choice.
Possible limits to the dissemination of these strategies may be technical difficulties, excess costs and time, non-standardized results, limited demand in clinical practice. For this reason, novel cryopreservation approaches are welcome to the scientific community.