Egg & Sperm Freezing
Freezing your eggs at an early reproductive age can help to preserve your fertility and maximise your chances of a future pregnancy.
How are eggs frozen?
Did you know that an egg is the largest cell in the human body? This means we need a special technique to freeze effectively. We use the vitrification technique to freeze eggs. Vitrification literally means ‘turning to glass’. The eggs are first dehydrated to remove as much water as possible. Then, after being bathed in a protective solution, they are plunged rapidly into liquid nitrogen at almost -200°C. This step is performed so quickly that prevents ice formation and results in a glass-like state.
Around 95% of eggs undergoing this super-fast freezing technique survive the freeze-thaw process and a high proportion of these are capable of undergoing ICSI (where a sperm is injected in to the egg to fertilise)
Why freeze your eggs?
Fertility is scientifically proven to be age dependent and since it is the age of a woman’s eggs which determines her fertility, the eggs of a 30 year old woman are much more likely to lead to successful conception than those of a 40 year old. Freezing your eggs at an early reproductive age can help to preserve your fertility and maximise your chances of a future pregnancy if you should experience fertility problems in the future.
A significant number of cancer cases occur in people of reproductive age and cancer treatments can harm your fertility. The effects can be temporary or permanent depending on factors such as the type of cancer , the treatment received and your age at the time of treatment. These treatments do not have to end the hopes of having a family though. Women with cancer may have the option to preserve their fertility by freezing their eggs.
Sperm can be preserved by freezing and used for treatment at a later time.
How is sperm frozen?
The sperm is analysed, divided into batches and then transferred into vials or straws. The sperm is combined with a cryoprotectant fluid and frozen in liquid nitrogen.
There are various reasons why you may feel you need to freeze your sperm, for instance:
- If you are about to undergo treatment such as chemotherapy which may result in infertility.
- If you are planning to have a vasectomy
- If you think you may be unable to produce a fresh sample for IVF treatment
How long can sperm be frozen?
As long as freezing conditions remain at a constant temperature, sperm can survive the freezing process indefinitely. Not all sperm survive the freeze thaw process but the length of time held in storage does not impact the chances of survival. Sperm can be held in storage in line with the storage consent terms