Cryopreservation is the term used to describe the process of freezing and storing sperm, eggs or surplus embryos from an in vitro fertilization cycle.
There are 2 methods currently used for freezing in IVF labs-slow freezing and vitrification (ultra-rapid freezing)
Vitrification is the process of converting something into a solid without any crystal formation. This is done by adding a cryo-protectant. This is important because ice crystal formation can be very damaging to frozen embryos.
Embryos can be frozen at the pronuclear stage (one cell), or at any stage after that up to and including the blastocyst stage (5-7 days after fertilization). Different cryoprotectants and freezing solutions and protocols are used for different stages of embryo development. Many IVF clinics freeze their embryos at the blastocyst stage
Sperm freezing also known as cryopreservation or semen banking is a technique of preserving sperm by freezing and storing it in liquid nitrogen at the temperature of -196⁰C that is used on a later date for fertilizing an egg.
Sperm freezing is useful if:
- you have a condition or are facing medical treatment for a condition, that may affect your fertility
- you are about to have a vasectomy
- you have a low sperm count or the quality of your sperm is deteriorating
- you have difficulty producing a sample on the day of fertility treatment
- you are at risk of injury or death (eg: you’re a member of the Armed Forces who is being deployed to a war zone)
Procedure before you store sperm
- You need to go through careful screening for HIV, HBV, HCV, etc. to avoid chances of infection.
- You need to give written consent regarding what will happen to your sperm if you cannot make decisions for yourself or die, whether anybody can use your sperm such as your partner or for research or if it can be donated for somebody else’s treatment and for how long you want to store your sperm
The standard time for storing sperm is 10 years, but you can extend the storage time up to 55 years. Before doing that your Andrologist will check the condition of the sperm in one of the vials and helps you decide on the fate of the frozen sperms.