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If you have completed any research about an infertility clinic, you may have come across the concept of egg freezing. While freezing sperm has been available since the 1950’s, egg freezing is a relatively new concept. A thawed human egg was used for a successful pregnancy in 1986. However, it took over a decade for egg freezing services to be offered in an infertility clinic in countries around the world.
How are Eggs Frozen?
The concept of egg freezing became more commonplace in the late 1990’s. This is due in part to a law passed in Italy. The law which was passed in 1994, prevented an infertility clinic from inseminating eggs in larger numbers. This forced the infertility specialists to freeze the remaining unfertilized eggs. This was a challenge for the medical profession as eggs contain a high water content and have a membrane which does not easily permit water to pass through. This can allow ice crystals to form and the salt concentration to increase when frozen. This can disrupt the internal structure, which makes the egg prone to swelling. However, techniques have developed over recent years including rapid freezing, which have made egg freezing more viable.
Why are Eggs Frozen?
Egg freezing is generally recommended in cases where the woman has no partner and is concerned for future fertility, for example women who are about to undergo cancer treatments such as chemotherapy, or at risk of premature menopause.
What is the Egg Freezing Process?
There are a number of steps in the egg freezing process. These include:
• Ovarian Stimulation:
This is the first stage of the egg freezing process, in which the ovaries are stimulated to increase egg production through the use of fertility medication. The type of stimulation is dependent on the specific medical circumstances of the woman, for example, if she is suffering from an estrogen sensitive form of cancer, the stimulation method is usually modified. This step takes approximately two weeks to produce sufficient eggs.
• Retrieval of the Eggs:
This is usually accomplished under sedation. The eggs are suctioned from the body using a needle. Each egg is examined to assess maturity. Your infertility clinic may only freeze mature eggs, although some facilities will mature the eggs before they are frozen.
• Freezing of the Eggs:
This is usually accomplished using either a slow freezing method or vitrification. Slow freezing entails using a cryoprotectant and a programmable freezer to slowly freeze the egg. Vitrification uses a high concentration of cryoprotectant and liquid nitrogen to rapidly reduce the temperature.
Considerations for Egg Freezing:
There are several aspects for consideration including that egg freezing is a relatively new technology. Therefore there is very little long term data available. According to the CDC, the transfer rate of frozen embryos resulted in a live birth in 29.3 percent of cases. If you are considering egg freezing, it is worth taking the time to consult an infertility clinic for further advice and guidance. These fertility specialists will be able to help you determine if egg freezing is the option best suited to your needs.