Human sperm vitrification: the state of the art

Abstract

Sperm cryopreservation has been widely used in assisted reproductive technology (ART) and has resulted in millions of live births. Two principal approaches have been adopted: conventional (slow) freezing and vitrification. As a traditional technique, slow freezing has been successfully employed and widely used at ART clinics whereas the latter, a process to solidify liquid into an amorphous or glassy state, may become a faster alternative method of sperm cryopreservation with significant benefits in regard to simple equipment and applicability to fertility centers. Sperm vitrification has its own limitations. Firstly, small volume of load is usually plunged to liquid nitrogen to achieve high cooling rate, which makes large volume sample cryopreservation less feasible. Secondly, direct contact with liquid nitrogen increases the potential risk of contamination. Recently, new carriers have been developed to facilitate improved control over the volume and speed, and new strategies have been implemented to minimize the contamination risk. In summary, although sperm vitrification has not yet been applied in routine sperm cryopreservation, its potential as a standard procedure is growing.

The effect of cysteine and glutamine on human sperm functional parameters during vitrification

“…cysteine, glutamine, human, sperm parameters, vitrification motility parameters and factors such as mitochondrial membrane potential and DNA integrity (Tao et al, 2020). Researchers have conducted extensive researches on removing free radicals from freezing-thawing environments (Pribenszky et al, 2010).…”

Protective effect of the superoxide dismutase mimetic MnTBAP during sperm vitrification process

“…Currently, the two principal methods applied to the cryopreservation of human spermatozoa are conventional slow freezing and vitrification. Sperm vitrification is a simple, fast and cost‐effective method which consists on the direct plunging of the sperm samples into liquid nitrogen and due to the rapid freezing causes no damage from intracellular ice crystallisation during cooling (Tao, Sanger, Saewu, & Leveille, 2020). Recently a systematic review and meta‐analysis concluded that vitrification is superior to conventional freezing in post‐thaw total and progressive motility (Li et al., 2019) and due to its advantages has a growing potential to become a standard procedure in ART clinics (Tao et al., 2020).…”

Sperm Selection Procedures for Optimizing the Outcome of ICSI in Patients with NOA

“…A comparative study demonstrated that progressive sperm motility and vitality were higher after conventional rapid freezing than after vitrification, whereas vitrification was more successful if normal morphology was the criterion [ 157 ]. Despite the widespread preference of the conventional technique in ART clinics, vitrification is recommended as a fast, practical, and low-cost method [ 158 , 159 ]. Rapid freezing also prevents damage due to intracellular ice crystallization during cooling [ 160 ].…”