It is also often used by trans women prior to medically transitioning in ways that affect fertility, such as feminizing hormone therapy and orchiectomies.
Cryoprotectant media may be supplemented with either egg yolk or soy lecithin, with the two having no statistically significant differences compared to each other regarding motility, morphology, ability to bind to hyaluronate in vitro, or DNA integrity after thawing.
Treatment of sperm with heparin binding proteins prior to cryopreservation showed decreased cryoinjury and generation of ROS.
[2] The addition of nerve growth factor as a cryoprotectant decreases sperm cell death rates and increased motility after thawing.
The solution helps prevent ice crystals from forming in the sperm, which can damage the cell membrane and affect its viability.
In this way, the crystallization of intracellular water and cryodamage is avoided, without using permeable cryoprotectants that can imply mutagenic risk.
It is extremely fast (-23000°C/min), so as a result it avoids the appearance of small ice crystals, preventing the "knife" effect.
The packaging method is a crucial aspect of cryopreservation processes, as it directly affects thermal stability, storage capacity, and the efficiency of sample thawing.
On the other hand, the exact thawing temperature seems to have only minor effect on sperm viability, acrosomal status, ATP content, and DNA.
[8] Some evidence suggests an increase in single-strand breaks, condensation and fragmentation of DNA in sperm after cryopreservation.
[9] In long-term follow-up studies, no evidence has been found either of an increase in birth defects or chromosomal abnormalities in people conceived from cryopreserved sperm compared with the general population.