Compared to our grandparents’ generation, many women these days are delaying marriage and/or parenthood so that they can concentrate on their careers and develop financial security. The result of this delay in having a family is an increase in difficulties with fertility.
The likelihood of a woman conceiving in her late 30's or early 40's is dramatically lower than in her late 20's and early 30's. The incidence of both subtle and obvious chromosomal abnormalities also rises very significantly for women in their late 30's and 40's.
For this reason, some women are choosing to ‘freeze’ their eggs while they are young and healthy so that the eggs can be used at a later age when they are ready to start a family.
Similarly, women who are facing cancer treatment sometimes choose to freeze their eggs for future use.
As Clinical Director for an IVF clinic, I thought it might be worthwhile to give readers an overview of this increasingly popular process.
At QFG Sunshine Coast we offer egg freezing by the vitrification method. This is a form of ultra-rapid cooling – so quickly that no ice crystals are formed during the process. Ice crystals that formed during the “old” freezing technique had the potential to damage the eggs during the freezing and subsequent thawing technique. Clinics overseas using vitrification are reporting pregnancy rates that are far superior compared to the “old” freezing technique.
A woman who wanted her eggs frozen would need to go through a conventional cycle of IVF with ovarian stimulation. This stimulates egg production so that we can collect 8 - 12 eggs at once. These eggs are assessed by the IVF scientists to ensure they are viable. You may need to have two collections over two cycles if too few of the eggs you produce are viable.
The egg collection is a day surgery procedure, generally carried out under general anaesthetic. Once frozen, the straws containing the eggs are stored in liquid nitrogen at -196 C.
When the woman decides she wants a baby and has a limited chance of success due to advancing age, her eggs are then thawed and placed in an IVF culture. Using the currently available freezing and thawing procedures, between 70 and 80% of frozen eggs are expected to survive the process. The eggs are then injected with sperm - either her partner’s or a donor’s. Then one or two embryos would be implanted in the uterus.
This process, while not inexpensive, means that an older women can have a successful pregnancy using her own eggs.
On a related topic, more and more men are having their sperm frozen and stored for future use. This is another procedure which QFG Sunshine Coast handles. Sperm freezing is a very successful process, with pregnancy rates very similar to those obtained with fresh sperm. Some men do this because they are facing cancer treatment which may affect their fertility, because they are having a vasectomy, or because they work in a high-risk occupation, such as the military.
If you are considering freezing eggs or sperm, see your GP first for a referral to one of our fertility specialists. Alternatively, call QFG Sunshine Coast (5493 7133) to speak to one of the nurses and get some background information first. Check the website at www.ivfq.com.au