Frozen sperm must be stored in extremely cold temperatures (-196 F), but in order to ensure that the fewest possible sperm are damaged, the freezing must be gradual. Generally, the following procedure is followed:
- If the sperm hasn't been previously tested, a comprehensive semen analysis should be performed on the first specimen in order to give you a complete picture of your sperm quantity and quality. Make sure that your sperm bank conducts a thorough semen analysis before banking. This will give you significant information on the quality of the sperm.
- Each subsequent specimen is analyzed prior to freezing to assess total number of moving sperm.
- Immediately after the specimen is analyzed, it is divided into smaller batches and transferred into vials for freezing. Each semen sample is mixed with a cryoprotectant, a harmless solution which helps protect the sperm from damage during the freezing process.
- The test tubes are gradually frozen in liquid nitrogen vapor, letting the sperm freeze slowly. After 30 to 60 minutes, they are transferred into liquid nitrogen tanks for permanent frozen storage. Each ejaculate will result in one or more vials being frozen; usually 2 or 3 vials can be obtained from each ejaculate. One vial is used for each insemination, so that one ejaculate may give enough sperm for 2 or 3 months of cervical inseminations.
- After a minimum of 48 hours have elapsed from the time of the initial freezing, an initial "test sample" is thawed and tested again to ascertain from each specimen how well the sperm survived the freezing. After the banking is complete, the results may be sent to you or discussed with your primary care physician. This information will be important to determine which specimen vials to thaw for an insemination.
Each sample is stored in its own specially marked storage unit. Some
cryobanks split the specimens, storing half of any individual's specimens in
two separate nitrogen tanks in case of tank malfunction. Some may actually
store the two tanks on separate physical sites in case of an unforeseeable
disaster to the building in which a tank is stored. The nitrogen tanks are
checked daily for temperature and liquid nitrogen leakage.
How many specimens should be frozen?
in general, 3 ejaculates should be frozen. The exact number depends on your sperm count, the time available for accumulating specimens, and other factors. Once the initial sperm count and the results of the freezing and thawing have been determined, it is easier to advise you how many samples should be stored.
How long can sperm be stored?
Pregnancies have been recorded with sperm frozen for up to 15 years. It is possible, however, that the sperm quality may deteriorate over time.
What testing is done on the sperm?
Each sample will have a semen analysis performed to make sure that there are enough sperm present to allow adequate pregnancy potential by routine insemination before freezing. It will be left up to you as to whether or not further samples will be frozen, if they are below this level.
Who has access to the semen samples?
Semen samples will be released to you upon written notification. You can also specify that another individual be able to obtain samples; this would usually be your wife. Again, written notification from your wife/designee would be necessary. In no instances would samples be used to inseminate someone other than the woman specified in the consent form. If your wife/designee changes, then a new consent form must be filled out.
For more information, please contact the North Texas Male Infertility
Center laboratory at 972-612-7131.
Thank you for visiting Legacy Male Health Institute, P.A., we hope information about freezing sperm will be helpful to you.
