Thoughtful Fertility Care is dedicated to empowering Chinese women, alleviating concerns about fertility challenges. As women increasingly embrace independence—working diligently, enjoying life, and achieving financial autonomy—marriage and childbirth are no longer seen as "mandatory life milestones." Egg freezing serves as a "remedy for regret," preserving the right to choose one's future path.
Egg freezing preserves fertility by retrieving and cryopreserving healthy eggs during a woman's peak reproductive years. This protects against natural egg depletion and quality decline associated with aging. When ready to conceive, the eggs are thawed and revived. Through assisted reproductive technology, they are fertilized with sperm in vitro to create healthy babies.
What is the current state of egg freezing technology? Is the success rate high? The origins of egg freezing trace back to livestock preservation for rare species. Since the world's first birth from a frozen-thawed embryo in 1984 and the first birth from a frozen-thawed egg in 1986, egg freezing has become a vital component of human assisted reproductive technology (ART).
Egg freezing technology has progressively advanced, now enabling rapid freezing. Also known as vitrification, this method rapidly cools the protective solution to -196°C, causing it to enter a glass-like state. This effectively prevents ice crystal formation and subsequent damage to egg cells during freezing. Medical literature worldwide reports a 90%-97% success rate for egg recovery after vitrification.Egg freezing at an advanced age is associated with higher miscarriage rates.
Globally, demand for egg freezing continues to expand.
However, women should consider six key factors before freezing eggs:
1. Freeze eggs early
Freezing eggs early is advisable, but not necessarily the earlier the better.
Freezing eggs before age 30 yields the highest future live birth rates. Yet the average age for egg freezing is around 37, as many women opt for the procedure in their late thirties or early forties.
For maximum future fertility success, freezing eggs before age 36 is optimal. At this stage, preserved eggs maintain sufficient quality for cryopreservation, and you're more likely to utilize them later.
While freezing eggs in your early twenties preserves many high-quality eggs, you're unlikely to know if you'll need them then, as natural conception remains possible.You may choose to freeze eggs at a slightly older age (but before fertility declines rapidly, ideally before age 35). This increases the likelihood you'll actually use your frozen eggs, avoiding the expense of the process only to discover you don't need them.
Egg freezing generally yields higher recovery rates for women over 35, while those under 35 experience lower rates. However, if you don't plan to conceive in the near future, freezing eggs is worth considering. Unlike men, women are born with a finite number of eggs, and this number is irreversible. Therefore, deciding to freeze eggs should be done early in life.
II. Egg Preservation Duration
Another reason women shouldn't freeze eggs too young (e.g., in their twenties) is that, technically, eggs can be frozen for 10–15 years (or potentially longer). However, freezing doesn't indefinitely extend fertility. It's best to thaw and transfer embryos before age 45, and no later than age 50.
III. Clinic Expertise
If considering egg freezing, choose a clinic with extensive experience in this procedure.
Also inquire whether the clinic can provide its own historical success rates for frozen eggs. Some clinics only offer averages derived from published data by other institutions.
You should also request to see success rates broken down by age, as the likelihood of successful pregnancy using eggs from a 32-year-old woman may differ significantly from that of a 39-year-old woman.
IV. During egg freezing, the number of follicles retrieved does not equal the number of eggs retrieved, which does not equal the number of future embryos.
The more eggs you freeze, the greater your chances of future pregnancy success—provided the eggs are of good quality.
Recent data indicates that to achieve a 75% success rate for one pregnancy, a 34-year-old woman needs to freeze 10 eggs;a 37-year-old requires 20 eggs; and a 42-year-old needs 60 eggs to achieve the same success rate.
During egg freezing, some eggs are lost. For example, a 36-year-old woman may produce 15 eggs after ovarian stimulation. However, some may be immature and unsuitable for freezing.
Some eggs may not freeze or thaw properly, becoming unable to be fertilized or reach the blastocyst stage (suitable for embryo transfer). By the end of the egg freezing process, only 4 embryos may remain viable for conception.
V. You May Require Multiple Freezing Cycles
Research indicates that freezing approximately 15 eggs is recommended to maximize future pregnancy success rates. However, the number of eggs produced and retrieved in a single stimulation cycle depends on the woman's age at freezing, her remaining ovarian reserve, and her response to ovarian stimulation.
This means some women may produce 15 eggs in a single cycle, while others require multiple stimulation and retrieval cycles to collect and freeze the same number—resulting in additional costs.
VI. Egg Freezing May Still Fail at Advanced Age
For women freezing eggs at age 36, the cumulative success rate of using previously frozen eggs in multiple IVF cycles remains lower than that of younger women.
Even when conceiving with eggs frozen in youth—such as through egg donation—older women face higher risks of pregnancy and childbirth complications compared to younger women.
We often encounter women considering egg freezing after age 40, by which time egg quality has declined and quantity may be limited.Here's a reminder for women around age 35: If your life plan includes having children but you're delaying motherhood for any reason, be sure to consult a fertility specialist or specialized assisted reproduction platform to assess your ovarian function and prepare for pregnancy early. Thoughtful Fertility, Weaving Dreams for the Future!