For those who want to delay childbearing, egg and embryo freezing are good options
For those who want to delay childbearing, egg and embryo freezing are good options.
Is your biological clock ticking? Vancouver fertility expert Dr. Beth Taylor explores the options of freezing your eggs and embryos
We exercise, care for our skin, take vitamins and eat clean foods. We feel younger than ever and in many ways we are – except in one very important way – our fertility. No matter what we do, our eggs are aging.
At birth, women are born with about two million eggs and we run out of them by the time we reach menopause, which occurs on average at the age of 51. As our eggs decline in number, they also decline in quality. This decline in egg quality can cause infertility, a higher risk of miscarriage as well as more conceptions with chromosomal problems (e.g. Down Syndrome). In the last few years before menopause, a woman’s egg quality is so poor that pregnancy is rare.
Freezing Your Eggs
So can you stop the biological clock? Sort of. Since the 1980s, scientists have been trying to freeze eggs, to stop them in time so women can use them later in life when their eggs are low or absent in number and quality. The complexity of the process of harvesting eggs and freezing them was great and the success rate was low, until very recently.
An improvement in the freezing technique called fast freezing, or vitirification, has dramatically improved the success of the procedure. In 2012, the American Society for Reproductive Medicine (ASRM) decided that the success and safety of egg freezing was such that they no longer consider egg freezing “experimental.”
The Process and Pregnancy Rates
Once eggs are frozen, they can remain stored for years. When a woman wishes to use her frozen eggs, they are thawed, fertilized with sperm to make embryos, and the embryos are put into her uterus to achieve a pregnancy. The pregnancy rate per embryo transfer is between 20 to 40 per cent, depending on the woman’s age when the eggs were frozen.
At What Age Should You Freeze Your Eggs?
Freezing eggs when you are younger is ideal and certainly under the age of 38 is best. Egg freezing after the age of 38 has a low success rate and is nearly zero after the age of 40.
It makes sense for a woman to freeze her eggs if she is single. Frozen eggs can be fertilized with sperm from a future partner so they can have children that are genetically related to them. If she is in a relationship, however, it is better for her to fertilize her eggs with her partner’s sperm to make embryos and freeze embryos.
Embryos are more likely to survive the freezing and thawing process and more likely to result in a pregnancy than frozen eggs. Before vitrification increased the success of egg freezing, many single women would fertilize their eggs with donor sperm and then freeze embryos, instead of eggs, as the pregnancy rates were much higher. Now, egg freezing success rates are approaching those of embryo freezing success rates, so most single women are choosing to freeze eggs, keeping the door open to Mr. Right’s sperm in the future.
The Risks of Freezing Eggs and Embryos
Like any medical treatment, there are some risks to egg and embryo freezing. Both treatments involve taking injectable medication to cause the ovaries to grow multiple eggs. The injections can have side effects like bloating, nausea and mood changes.
Eggs are then removed from the body with a needle that goes through the vagina into the ovaries, a process that can cause bleeding, infection or damage to internal organs (less than one in 1000 cases, fortunately). Freezing your eggs or embryos does not a guarantee that a healthy pregnancy will occur, so (gulp) do not put all your eggs in the frozen basket! Plan to start your family sooner than later.
How Much Does Egg and Embryo Freezing Cost?
The treatment costs $7500 plus the cost of medications, which is typically $2000 to $3000. Once eggs or embryos are stored, there is a $200 to $400 annual storage free. No part of the treatment is covered by the B.C. Provincial Health Plan, but many private insurance companies will cover part or all of the treatment.
In an ideal world, single women and couples would try to conceive in their 20s and early 30s, but we know that more and more women are having children in their late 30s and 40s when their biological clocks are running, or have run out. For those women who plan to delay childbearing, egg and embryo freezing are good options.
To learn more about your fertility and whether egg or embryo freezing are good options for you, talk to a fertility specialist who can help assess your current and future fertility. There really is no time like the present!
Dr Taylor is co-founder and co-director of Olive Fertility Centre. She is a Clinical Associate Professor at UBC and an active staff member at BC Women’s Hospital and Vancouver General Hospital. She has expertise in all areas of reproductive endocrinology and infertility care.