Egg freezing: Can we pause the biological clock?

Mainstream media often sends misleading messages to women about reproductive health and infertility.

We have all seen magazine covers at the grocery store featuring celebrities well into their 40s and 50s, clutching baby bumps or newborn babies, suggesting an apparent ease and ability to conceive naturally at these ages.Unfortunately, this isn’t the whole truth. The “big lie” here is that women falsely believe they can delay pregnancy indefinitely.

What celebrities often omit from birth stories is that they struggled with infertility, and in some cases became pregnant with the help of assisted reproductive technologies, egg donation, or both. This is because as a woman ages her eggs are less likely to result in a healthy pregnancy. The good news is that we now have the ability to freeze a woman’s eggs, while she is young, for possible use later in life. This medical breakthrough is a powerful tool that allows women to take control of their reproductive freedom.

Here are 8 fast facts about female fertility, and about egg freezing:

1. Women are born with 1-2 million eggs; this number decreases to 500,000 by puberty, 24,000 by age 37 and 1,000 by menopause (average age 51.2 years).  Women do not make new eggs throughout their lifetime (unlike men, who continuously make new sperm). Approximately 1,000 eggs are lost with each menstrual cycle.
2. In combination with an ultrasound to count the number of small follicles that are visible in a woman’s ovaries, a simple blood test can estimate how many eggs remain (this is often referred to as the “ovarian reserve”). This blood test measures the level of Anti-Müllerian Hormone (AMH), which is made by growing eggs within the ovary.
3. The reality is that a woman’s fertility starts to decline at age 32 and decreases more rapidly after age 37.  This is a function of two changes that occur with age – the total number of eggs decrease, and at the same time the quality of these eggs decrease. Overall, this means that as a woman ages, there are fewer genetically normal eggs in her ovaries that are capable of making a baby.
4. Egg freezing became a viable option for elective fertility preservation in the United States in 2012, when the American Society for Reproductive Medicine (ASRM) published a guideline suggesting that egg freezing was no longer considered an experimental procedure.
5. There are many possible reasons a woman might pursue egg freezing, including: fertility preservation before undergoing chemotherapy or radiation for a cancer diagnosis, fertility preservation before undergoing surgery that may affect the ovaries, severe endometriosis, a risk of premature ovarian failure, egg donation, and elective fertility preservation.
6. The process for egg freezing involves approximately two weeks of injectable medications that stimulate many eggs to grow (controlled ovarian hyperstimulation), which is monitored with ultrasounds. When the eggs are ready, they are retrieved during a day procedure under conscious sedation. Embryologists then assess how many mature eggs were retrieved. Those are then frozen (“vitrified”) and stored indefinitely.
7. The optimal age to electively freeze eggs is when a woman is in her early 30s. One study demonstrated a 74 percent live birth rate in women who froze eggs before the age of 34. However, individual counseling is important when deciding whether or not to pursue egg preservation.
8. To date, published studies suggest that babies born from eggs that were previously frozen have no increased incidence of adverse health affects, when compared to babies who were born with eggs that had not been frozen. This data is reassuring and long term studies are ongoing.

As a physician specializing in reproductive endocrinology and infertility, I think it’s important all women in their early 30s – or earlier if they are at risk for diminished ovarian reserve – are counseled about the natural age-related decline in fertility. It is very exciting that we can now offer egg freezing to our patients as a means to “pause” the biological clock.