10/20/2014 05:55 EDT | Updated 12/21/2014 05:59 EST

Egg Freezing Deserves Serious Consideration

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Egg freezing has sparked widespread media interest after Apple and Facebook recently announced they would cover the cost of the fertility procedure up to $20,000. This caused some serious debate. Some interpreted this as the tech giants' way of giving women more of a choice around career and starting a family; others saw this as a chauvinistic attempt to recruit and retain female employees.

To further understand why this is such a contentious issue, here is some background information on the procedure and how it applies to Canadians:

What is egg freezing?

Egg freezing is a technique in which a woman's eggs are extracted, frozen and stored. Originally this procedure was developed to help cancer patients preserve their fertility when undergoing treatments such as chemotherapy and radiation, known causes of infertility.

The procedure is still used today to help cancer survivors, along with many other patients who experience unforeseen medical conditions that can reduce their chances of having a baby. As egg freezing techniques have evolved, some women have chosen to have elective egg freezing to help increase their chances of conceiving at a later stage in life.

How does it work?

Vitrification, or "flash freezing," is the egg freezing method currently used today. This involves water being removed from the egg then the egg being rapidly cooled to a temperature of -160 to -196°C. When a patient is ready to conceive, the eggs are "warmed," fertilized and placed into the mother's womb. Although there is no way of knowing whether the eggs have been damaged in the freezing process until the eggs are used, technological advancements and improved methodologies have increased egg survival rates to more than 90 per cent, achieving comparable pregnancy rates of similarly aged in vitro fertilization (IVF) patients who use fresh eggs.

What are the benefits of egg freezing?

Egg freezing is first and foremost a good technique to help preserve fertility. As mentioned previously, patients who have to receive medical procedures such as radiation and chemotherapy often freeze their eggs prior to receiving treatment so they have viable eggs after they are cancer-free.

While some patients that undergo cancer treatment choose to freeze embryos rather than eggs to preserve their fertility, there are some countries where policies prevent the freezing of fertilized eggs (pre-embryos) on religious or moral grounds. Egg freezing is a good alternative for those who are uncomfortable with embryo cryopreservation.

More recently, some women have chosen to freeze their eggs to alleviate the pressure of having a child while still trying to develop their careers. Many argue that women, especially those working in the technology sector, are working in male-dominated, less family-oriented industries, making professional advancement more difficult for women looking to take time off to have children. As it currently stands, egg freezing is an option, though not a guarantee, to facilitate decision making that includes both family and career goals.

Egg freezing also allows those who are waiting to find the right partner, focusing on their education or just generally hoping to extend their fertility a chance at having a child later in life.

Another benefit of egg freezing is the education at the time of the consultation. Most women who have age related infertility have not frozen their eggs nor do they understand the impact of age on egg quality and fertility at the time of their first consult. When women speak to their fertility specialists about egg freezing, those who are in relationships may decide to try conceiving immediately once they understand the potential consequences of delaying; some single women may opt to pursue donor sperm insemination to have a baby while others may choose to freeze their eggs.

What is the optimum age for women to get their eggs frozen?

Although this might seem like a simple question, it is actually difficult to answer. A woman's fertility is dependent on both the number and quality of eggs remaining in the ovaries, and as women age, both of these measures decrease. Although it's best to retrieve eggs at a young age, some fertility specialists believe that the ideal time to consider egg freezing is around 30 to 35 years of age. If eggs are frozen before 30, they might never be used given that chances of natural conception are high; if the eggs are retrieved past 35, there is a higher chance that the egg has increased chromosomal abnormality or decreased egg quality due to other factors.

Whether 30 to 35 is the best time to have eggs frozen is still a debated topic within the infertility field.

What are the risks of egg freezing?

The most significant risk tends to be a false sense of assurance that because one has frozen her eggs, there is no expiration date for conception. The fact is, many women who freeze their eggs have not yet tested their fertility and do not know if they face other challenges in conceiving. If a woman delays child bearing beyond a certain point, there may be few alternatives if the frozen eggs do not work. For this reason, fertility specialists still advise women and couples to attempt conception naturally as soon as they are ready. Conditions such as diminished ovarian reserves, endometriosis and uterine factor infertility may yet be undiagnosed.

Scientifically speaking, risks of egg freezing are the same as that of IVF. During the egg stimulation process, bloating occurs when a woman responds to the fertility medications. In some cases, the bloating can become potentially dangerous, developing into a condition called ovarian hyperstimulation syndrome (OHSS). In IVF, the risk of having OHSS is about one to two per cent; recent studies have found that there is a lower risk of OHSS for egg freezing patients than those using IVF.

Another medical risk is a condition called ovarian torsion. This affects around 1 in 1,500 patients, and occurs when an enlarged ovary twists. It requires emergency surgery to "untwist" the ovary to prevent infarction.

Cost and Coverage in Canada

Egg freezing costs between $7,000 to $10,000 in Canada. This includes the medications required for the procedure but not the thawing process or the transfer of the egg to the mother when she's ready to conceive. The latter procedures cost approximately an additional $3,000.

When a patient is ready for egg freezing, the initial consult with a fertility specialist is covered by healthcare plans if you have a referral from your family doctor. At the first consultation, an assessment of your personal and reproductive history will be undertaken and an ultrasound may be performed to assess ovarian reserve by measuring the "antral follicle count." Antral follicle count is the number of small follicles present in the ovaries that may contain eggs. This often predicts the number of eggs that can be harvested during the actual procedure.

Each month, a cohort of follicles grows to allow one follicle to mature and ovulate. The remainder of the follicles die until a new group grows the next month. Therefore, egg retrieval does not accelerate the time to menopause or decrease egg reserves; it simply rescues the eggs that were destined to "die" that month.

Often a day-three follicle stimulating hormone (FSH) test and estradiol level will be ordered for the patient at the initial consultation to predict ovarian reserves. While these tests are covered by provincial or territorial healthcare plans, they are increasingly being replaced by anti-Müllerian hormone testing, a procedure that is not covered, but is a more accurate assessment of ovarian reserve.

As of yet, most healthcare plans have limited infertility or fertility preservation coverage. Some plans will cover medications that accompany certain procedures. In Canada, a program called "Navigating Your Insurer" helps candidates identify coverage available to them in their extended health plans. Interestingly, as egg freezing becomes more mainstream and reliable, several employers are starting to provide coverage for their employees.

Why should we care about egg freezing?

Starting a family is a very emotional and personal decision. There is often a stigma surrounding infertility: women are often uncomfortable bringing up their troubles or concerns about having a child. Learning about technologies such as egg freezing can be the first step in demystifying and addressing reproductive health so women and men can make informed decisions on how they can have a child when it's best for them.

CORRECTION: A previous version of this blog erroneously stated that eggs were rapidly cooled to a temperature below 1,000°C.