Clin Exp Reprod Med.  2019 Jun;46(2):67-75. 10.5653/cerm.2019.46.2.67.

Does conventional freezing affect sperm DNA fragmentation?

• Le MT
• Nguyen TT
• Nguyen TT
• Nguyen TV
• Nguyen TA
• Nguyen QH
• Cao TN

• KMID: 2452645
• DOI: http://doi.org/10.5653/cerm.2019.46.2.67

Abstract

OBJECTIVE
Sperm cryopreservation has been widely used in assisted reproductive technology, as it offers great potential for the treatment of some types of male infertility. However, cryopreservation may result in changes in membrane lipid composition and acrosome status, as well as reductions in sperm motility and viability. This study aimed to evaluate sperm DNA fragmentation damage caused by conventional freezing using the sperm chromatin dispersion test.
METHODS
In total, 120 fresh human semen samples were frozen by conventional methods, using SpermFreeze Solution as a cryoprotectant. Routine semen analysis and a Halosperm test (using the Halosperm kit) were performed on each sample before freezing and after thawing. Semen parameters and sperm DNA fragmentation were compared between these groups.
RESULTS
There was a significant decrease in sperm progressive motility, viability, and normal morphology after conventional freezing (32.78%, 79.58%, and 3.87% vs. 16%, 55.99%, and 2.55%, respectively). The sperm head, midpiece, and tail defect rate increased slightly after freezing. Furthermore, the DNA fragmentation index (DFI) was significantly higher after thawing than before freezing (19.21% prior to freezing vs. 22.23% after thawing). Significant increases in the DFI after cryopreservation were observed in samples with both normal and abnormal motility and morphology, as well as in those with normal viability.
CONCLUSION
Conventional freezing seems to damage some sperm parameters, in particular causing a reduction in sperm DNA integrity.

Keyword

Cryopreservation; DNA fragmentation; Freezing; Halosperm test; Spermatozoa

MeSH Terms

Acrosome
Chromatin
Cryopreservation
DNA Fragmentation*
DNA*
Freezing*
Humans
Infertility, Male
Male
Membranes
Reproductive Techniques, Assisted
Semen
Semen Analysis
Sperm Head
Sperm Motility
Spermatozoa*
Tail
Chromatin
DNA