Gamete cryopreservation could help improve the fertility of men whose spermatozoa show a high level of prefreeze DNA fragmentation, study findings indicate.
Laura Thomson (Fertility First, Hurstville, Australia) and co-authors note potential cryoinjury of sperm from subfertile men is an issue of primary concern “considering that subfertile men form a very large proportion of the men requiring semen cryopreservation.”
The findings were observed during a study comparing different cryoprotectants used to store spermatozoa for fertility treatment. The study involved 320 men who presented for fertility investigations and provided semen samples.
Post-thaw sperm DNA integrity was unaffected by the type of cryoprotectant used during freezing, but showed a significant, negative correlation with the prefreeze level of DNA fragmentation. Among men with prefreeze sperm DNA fragmentation levels within the normal range, 89 percent showed an increase in fragmentation post-thaw. Conversely, 64 percent of those with very high levels of prefreeze fragmentation showed a decrease in fragmentation post-thaw.
The authors suggest that the result “gives rise to a possible novel method of reducing fragmentation in sperm used for assisted reproductive technology treatment cycles, in some cases without the need for invasive and expensive testicular sperm retrievals.”