Comparison between mechanical freezer and conventional freezing using liquid nitrogen in normozoospermia

Area of Science:

• Reproductive Medicine
• Cryobiology
• Sperm Preservation

Background:

• Conventional semen cryopreservation utilizes liquid nitrogen at -196°C.
• An alternative ultra-low temperature technique using mechanical freezers at -85°C was investigated.
• This study aimed to evaluate the efficacy of -85°C cryopreservation as a substitute for the traditional method.

Purpose of the Study:

• To assess the feasibility of human semen cryopreservation at -85°C.
• To compare the effectiveness of ultra-low temperature freezing with conventional liquid nitrogen technique.
• To determine sperm quality parameters (concentration, motility, DNA integrity) after short-term storage.

Main Methods:

• Prospective experimental study conducted in a Medically Assisted Conception unit.
• Inclusion of normozoospermic semen samples.
• Assessment of sperm concentration, motility, and intact DNA before and after freezing/thawing at 7 and 30 days.

Main Results:

• Sperm cryopreservation at -85°C demonstrated comparable results to liquid nitrogen storage for up to 30 days.
• No statistically significant differences were observed in sperm concentration (p=0.1 Day 7, p=0.2 Day 30).
• Motility (p=0.9 Day 7, p=0.5 Day 30) and DNA integrity (p=0.1 Day 7, p=0.2 Day 30) remained statistically similar between the two methods.

Conclusions:

• Short-term sperm storage at -85°C is a viable alternative to conventional liquid nitrogen cryopreservation.
• The ultra-low temperature technique yields comparable post-thaw results for sperm quality.
• This method offers a potential alternative for assisted conception procedures requiring short-term sperm banking.