Egg and Embryo freezing is used during fertility procedures for a variety of reasons. When there are extra embryos during the IVF process, high quality embryos can be frozen. Egg freezing is done for a variety of reasons, including fertility preservation after the diagnosis of cancer, but also for social reasons.
Social egg freezing refers to the banking of eggs for the purpose of delaying childbearing. In 2013 the American Society for Reproductive Medicine (ASRM) removed the ‘experimental’ label from this technology, and since then its popularity has increased exponentially. Social egg freezing is important because women in our society are choosing to have children later in life. According to Statistics Canada 2010 marked the first time in our history that more women in their 30’s were having children than women in their 20’s. In British Columbia the percentage of live births to women age 35 and older rose from 11% in 1990 to 23 % in 2011. The most common reason that women delay having a family is the lack of a suitable partner.
In order to freeze eggs, a woman must undergo a very similar process to an IVF cycle. This involves injections of gonadotropin hormones for approximately 10 days to stimulate the eggs to grow. The eggs are then removed from the ovaries and checked under a microscope for maturity. Unfortunately, egg quality cannot be tested at this point but it can be inferred based on a woman’s age. Mature eggs are then frozen (cryopreserved) using flash-freezing technology called vitrification. Eggs can be frozen for an indefinite amount of time without damage to the eggs. At our centre, women can use their frozen eggs to achieve a pregnancy up until age 50.
Vitrification provides the ability to freeze eggs and embryos with a much higher degree of success. In this process, the tissue undergoes a controlled plunge into liquid nitrogen, within a protecting solution. The thaw process permits excellent cell recovery, and in several trials, the survival rates of embryos is up to 15X higher versus older techniques. This superior method permits multiple new fertility treatments such as high performance egg freezing, embryo biopsy for genetic screening, and a myriad of other benefits.
Because a woman is born with all of her eggs, the decrease throughout life in both quality and quantity. The ideal age to freeze eggs is around 34 years, although many women choose to wait until later in life and they can still have excellent results. Our doctors published a review of social egg freezing in the British Columbia Medical Journal which can be found here if you would like to read more.