Frequently Asked Questions: SpermFreezeTM / SpermFreezeTM SSP

FAQ1: Do I need to add egg-yolk to SpermFreezeTM (SSP) before use?
No, SpermFreezeTM (SSP) is ready-to-use and does not require any additives.

FAQ2: Does SpermFreezeTM (SSP) contain antibiotics?
No, SpermFreezeTM (SSP) does not contain any antibiotics.

FAQ3: Can I use SpermFreezeTM (SSP) for TESE?
Unfortunately, the cryopreservation of TESE (testicular sperm extraction) samples is no longer listed in the intended use of SpermFreezeTM (SSP), because the new European Medical Device Regulation requires FertiPro to have more clinical data to support this use. If your center can provide historical data on this, please contact

FAQ4: How long can I keep sperm in a frozen state?
Our data support a lifetime of at least 10 years. 20 sperm donations from different donors were frozen with FertiPro Sperm Freezing media between 2005-2009. Samples were thawed after two weeks cryopreservation and after 11-15 years. Progressive sperm motility was compared before and after freezing. An acceptable yield was found after 11-15 years, but progressive sperm motility decreased ±14% (on average) compared to samples thawed after two weeks.

FAQ5: We have noted that after thawing the tails of the spermatozoa are curled. Is this normal?
No this is not normal. Curling of the tail occurs because of osmotic shock when SpermFreezeTM (SSP) is added to the semen sample. To avoid this, add SpermFreezeTM (SSP) slowly and dropwise, while swirling the container that holds the semen sample. This way the spermatozoa have ample time to adjust to the new osmotic equilibrium.

FAQ6: What survival rates should we expect after freezing/ thawing ?
The number of sperm cells surviving a freezing procedure can vary significantly between samples and between patients/ donors. In general, a reduction in sperm motility of 50-60% after cryopreservation with SpermFreezeTM (SSP) is considered as acceptable.

FAQ7: How long can I use SpermFreezeTM (SSP) after opening the bottle?
We have performed in-use testing on SpermFreezeTM (SSP) which supports the use of the media up to 7 days, taking into consideration that the bottle was opened under sterile conditions and the product was stored at 2-8°C after opening. In addition and as indicated in the IFU it is advised to:

  • Keep the product in its original container until the day of use and
  • Depending on the number of procedures that will be performed on one day, remove the required volume of medium under aseptic conditions in an appropriate sterile recipient. This is in order to avoid multiple opening/ warming cycles of the medium. Discard excess (unused) media.

FAQ8: Can SpermFreezeTM (SSP) also be used with cryotubes instead of straws?
Yes, the same protocol as mentioned in the instructions for use of SpermFreezeTM (SSP) can be applied.

FAQ9: Why place an air bubble at the end of the straw?
An air bubble is placed at the end of the straw in order to prevent rupture of the seal when the SpermFreezeTM (SSP)/ semen mix expands during freezing.

FAQ10: Is SpermFreezeTM (SSP) IUI-ready? Do I need to wash the thawed semen sample before further use?
No, SpermFreezeTM (SSP) is not IUI-ready. Thawed semen samples must be washed before further use to avoid contact of the cryopreservation medium with the uterus.

FAQ11: What should be the temperature of the thawing procedure (tap water)?
The temperature is not critical, data indicated that thawing at room temperature or 37°C does not give significantly different results.

FAQ12: Can a sample be washed or concentrated before freezing?
Ideally, cryopreservation is performed on native semen samples. In case of very low sperm concentrations it is advisable to concentrate the sperm before freezing. In case of very high sperm concentration, sperm can be diluted with FertiCult™ Flushing medium before freezing, if preferred.

FAQ13: What is the difference between SpermFreezeTM and SpermFreezeTM SSP?
SpermFreezeTM SSP has a higher glycerol concentration (27% vs 15% in SpermFreezeTM), which results in less dilution (SpermFreezeTM requires 0.7-1ml medium for 1ml sperm, SpermFreezeTM SSP requires 1ml medium for 3ml sperm). This reduces the number of straws per semen sample for SpermFreezeTM SSP, but keeps the same end concentration of glycerol as SpermFreezeTM. There is no difference in thawing procedure.