Because of the lowering of semen quality during the freeze-=haw process, cryoprservation of human semen has focused on long-term banking for artificial insemination by donor (AID).
If this loss can be overcome, cryopreservation also will provide various advantages for artificial insemination with husband semen (AIH) and in vitro fertilization - embryo replacement (IVF-ER). We undertook experiments using discontinuous
Percoll
gradient methods to compare the motility and concentration of sperm after different methods of preparation. In the first group of 20 specimens, liquefied fresh semen was washed and concentrated by centrifugation, then frozen and thawed.
In the second group of 20 specimens, the procedures were reversed : before liquefied fresh semen was washed and concentrated, it was frozen and thawed.
In both groups, sperm concentration and motility were, as expected, higher after washing and concentration: 84±12×10E6/mL and 66±14% vs 48±1×10E6/mL and 54±3% in Group 1 and 43±1×10E6/mL and 25±6×10E6/mL and 42±9% in Group 2. In both
groups,
sperm motility was lower after cryopreservation, being 21±2% in Group 1 and 14±3% in Group 2.
These results suggest that although cryopreservation reduces sperm numbers and motility, washing and concentration by the discontinous Percoll gradient method prior to or after freezing can help prevent losses in semen quality.
This method therefore may be more effective in the preparation of sperm for AIH or IVF-ER.
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