Stopping the biological clock through egg freezing has long been the ultimate feminist fantasy. The pill was the first step, enabling women to delay childbearing, a revolution that profoundly altered society. But over the past five decades, the price women have paid has been age-related infertility, of epic proportions. Many young women believe they can wait until their 40s to have children, but that is often time’s wishful thinking. At age 40, more than half the female population will not be able to conceive without help, and by 44, even with IVF, success rates are low. No matter how healthy the diet or strenuous the exercise, a woman’s eggs still get old.
Why consider egg freezing?
Fertility rates are very closely linked to age. “The reproductive age of a woman is usually from about the age of 13, when the menstrual cycle begins, to 43 years of age,” says Dr Paul le Roux of the South African Society of Reproductive Medicine Gynaecological Endoscopy (SASREG). “As a woman gets older, the quality of her eggs deteriorates and this makes it increasingly difficult for her to conceive.”
The decline in egg quality is significant from the time a woman reaches her mid-thirties and the decline is even more rapid over the age of 40. With one in three couples at age 37 experiencing infertility due to deteriorating egg quality, Dr Le Roux recommends egg freezing, as a viable option for younger women who’d like to postpone conception to a later date.
What is the process?
Once a woman has made the decision to freeze her eggs, she undergoes a brief examination (using ultrasound) to estimate the number of resting eggs in the ovaries. According to Dr Le Roux, after the ovarian reserve has been determined, the woman is given hormone injections for two weeks to stimulate the growth of the eggs. “A small procedure under anesthesia then allows the eggs to be extracted vaginally and frozen in an IVF laboratory, and the eggs can stay frozen for more than five years”, affirms Le Roux.
As the largest cells in the human body, eggs contain a lot of water and as such, crystals can form within the eggs and damage them during the freezing process. Technicians therefore remove the water from the eggs and bathe them in an antifreeze solution before the egg is frozen. Laboratories vary in how they conduct the egg freezing process. Some prefer a slow egg freeze technique, while other use a flash egg freezing process called vitrification. Once the eggs are frozen, they’re stored at very low temperatures in liquid nitrogen.
When ready to conceive, the eggs are thawed and injected with a needle containing a single sperm – though a procedure called ICSI (IntraCytoplasmic Sperm Injection). The eggs then develop into embryos, which are implanted into the uterus using a catheter.
What is the best age to freeze eggs?
Elective egg freezing holds promise for women who want to preserve their fertility and delay childbearing. However, one must think of egg freezing as you would any investment. Invest when you’re younger for the reward when you’re older. The younger and healthier the eggs are, the more likely it is that a woman will be able to conceive later on with this type of technological assistance – although there are no guarantees. “The success rates of conception when using frozen eggs is slightly below the usual IVF pregnancy rate,” comments Dr Le Roux. “With one batch of frozen eggs from a woman who is 35 years old, the success rate of conception will be around 40%.”
According to Dr Le Roux, who practices reproductive medicine at the Cape Fertility Clinic, the most favourable outcomes are for women under the age of 35 who get their eggs frozen. “It’s not advisable for women to try and freeze their eggs once they’re older than 40,” affirms Dr Le Roux. “Unfortunately, many women don’t even start thinking about freezing their eggs until they are approaching 40,” he continues.
To date many babies have been born from frozen eggs with no increased rate of birth defects when compared to the general population, and according to Dr Le Roux, once a woman is pregnant with an egg that was frozen, the pregnancy would continue as per normal with no additional risks.
“Continuous efforts are being made to refine the process even more,” says Dr Le Roux. “There are many new developments currently underway in the field of reproductive medicine and it’s these very cutting edge technologies and treatment options that would have been considered science fiction 15 years ago.”
Freezing eggs offers women planning to have children after the age of 35 the opportunity to effectively slow down their biological clocks. Egg freezing gives women the unprecedented chance to store their eggs during their reproductive prime for use when they wish to start or expand their families.