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Meet the Future of Egg Freezing

When it comes to getting pregnant, there are a lot of variables to consider, including your age, health and the fertility of your partner. When you’re dealing with any sort of assisted reproductive technology — basically, anything involving a lab — there are more opportunities for environmental factors like the temperature and air quality to interfere.

For example, when a woman freezes her eggs, the eggs may not survive the thawing process to even make it to IVF — a significant but little-discussed fertility challenge.

But a revolutionary state-of-the-art egg-freezing lab in New York City is looking to remove those variables from the process, even going so far as to guarantee 12 frozen viable eggs with a 100 percent survival rate. Let’s look at how this is possible.

100 percent survival rate

Extend Fertility first made the news last year when they opened the first clinic in the United States dedicated exclusively to egg freezing. Unlike most clinics, Extend Fertility doesn’t offer services like IVF or sperm motility screenings — they only work with women looking to freeze eggs, from first consultations to retrieval to arranging long-term storage in a natural disaster-proof facility.

Because the clinic only deals in services related to egg freezing, it is able to provide highly personalized and specialized care for each patient. Now, Extend Fertility is taking their single-purpose clinic one step further, becoming the first clinic on the East Coast to offer the Cryotec freezing method — and a near 100 percent post-thaw survival rate according to Embryology Laboratory Assistant Director Dr. Leslie Ramirez.

To clarify, the egg survival rate refers to the percentage of eggs that are considered viable after they have been frozen and thawed. It does not in any way guarantee that they will result in successfully fertilized embryos that, when implanted via IVF, result in guaranteed babies.

two embryologists
Image: Extend Fertility

More: Freezing Your Eggs Isn’t as Easy Peasy as They Make It Seem

Developed by Dr. Masashige Kuwayama in Japan, the Cryotec method is considered the most advanced egg-freezing technique currently in practice, limiting potential damage to the eggs during every step of the process. Each tool and technique is specifically designed to ensure that any chances for error are minimized.

How is this different from other egg-freezing methods?

Since egg freezing started in 1986, what is known as a “slow-freeze” technique was widely used for the first 25 years. This is exactly what it sounds like: a process that takes a few hours to get the egg cell down to the final storing temperature of minus 196 degrees C (around minus 320 degrees F).

Vitrification, on the other hand, is essentially flash-freezing, meaning that it cools the cell down to minus 196 degrees C within a few minutes. The Cryotec method used at Extend Fertility is a specific type of vitrification in which, in addition to speed, other variables like the air quality and temperature in the lab are controlled.

It turns out that speed makes all the difference in terms of quality of frozen eggs. The slow-freeze method provides time for ice crystals to form in the cell, which may cause damage to its structures and reduce the chance that it will be viable after it’s thawed. Unlike other biological materials like sperm, egg cells have a much higher water content and because of that are more likely to develop harmful ice crystals.

close up on egg incubator
Image: Extend Fertility

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So how much of a difference does the process make? A lot, actually. One study by the Center for Reproductive Medicine found that eggs frozen via vitrification methods had a 91 percent survival rate, compared to a 61 percent survival rate of eggs stored using slow freezing. The Cryotec method bumps the survival rate up to 100 percent by controlling all environmental factors and utilizing specifically designed tools. Despite the existence of more successful methods, some embryologists still use slow-freezing methods today.

It’s all about the environment

Beyond adopting the flash-freezing technique, the lab at Extend Fertility also takes several precautions to create the safest possible environment for the eggs — many of which are unique to their facility. This includes an air-isolating system, which keeps the number of air particles per cubic foot below 1,000 (compared to a typical office building, which contains anywhere from 500,000 to 1 million particles per cubic foot of air).

There are also temperature controls throughout the lab, making sure that any air or surface the eggs come into contact with are warmed to body temperature (37 degrees C). Even the layout of the lab was designed to minimize distances egg cells travel within the room, decreasing any possible chances of accident or error.

egg freezing
Image: Extend Fertility

A goal-oriented pricing model

One cycle of egg freezing — meaning the process involving stimulating ovaries and retrieving the eggs — typically costs around $10,000. There’s no way to guarantee the number of eggs that will be available and retrieved during each cycle, so it may take multiple attempts to get a patient’s total desired number of eggs.

A goal-oriented pricing model, like the one adopted at Extend Fertility, takes a different approach. For around half the price — $4,990 to be specific — the clinic guarantees at least 12 viable frozen eggs, which they will retrieve through up to four cycles. One cycle takes around two weeks, and involves eight to 11 days of hormone injections followed by an in-office retrieval process, which takes between 10 and 15 minutes and is performed under local anesthesia.

Later on the day of retrieval, a clinician will call the woman to let her know how many eggs they were able to get. Then, the following day, they will let her know how many of those eggs are of high enough quality to be frozen. The number of viable eggs per cycle differs woman to woman, which is why the clinic offers up to four cycles to retrieve 12 quality eggs.

Frozen eggs on a monitor
Image: Extend Fertility

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Why 12 eggs? The thought behind this is that it’s the equivalent of one year’s worth of fertility, and is optimal for women over 30 who are trying to conceive.

So what’s the catch? The seemingly low $4,990 price point does not include the cost of medications required for ovarian stimulation (that will add on between $2,000 and 4,000) or long-term storage ($450 per year). But a typical egg-freezing cycle also doesn’t include medication or storage costs, so it still comes in less than traditional fertility clinics.

The future of freezing

While the Cryotec technique is currently only available at a handful of clinics in the United States (Extend Fertility is Dr. Kuwayama’s east coast representative), it does represent what is likely to be the future of egg freezing. So even if you don’t live in New York, this is a method that should become more widely available as other clinics adopt the technique.

Egg freezer
Image: Extend Fertility

The freezing process itself is only one component of fertility preservation. This article is the first in a series taking a closer look at all things related to egg freezing, including state-of-the-art technology and research, women’s firsthand experiences and advice from doctors and fertility specialists.

If there are any topics related to egg freezing you would like to see covered, please contact us at

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