All You Need to Know about Egg freezing

These days many women delay having families. They may not be in a committed relationship and ready to marry, they may want to pursue a career first, and they don’t feel totally ready to have a family. However, as women age, their egg quality declines resulting in fertility issues. Egg freezing has become a perfect solution for those women who want to preserve their eggs at a younger reproductive age, for later use.

But what exactly is egg freezing? What are the details one should know? Today, Superior A.R.T has all the answers.

What is egg freezing?

Oocyte cryopreservation, commonly referred to as egg freezing, is a method to maintain the supply of quality female eggs by freezing unfertilized eggs and storing them for future use. It is like freezing time, stopping egg deterioration as women age, storing the “younger” eggs for future use. The frozen eggs can then be used when the woman is ready to get pregnant, using assisted reproductive technologies such as ICSI or IVF where eggs and sperm are externally fertilized. The fertilized eggs (or embryos) are allowed to develop and then placed into a woman’s uterus to further develop and grow into a lovely baby.

Who should consider egg freezing?

The circumstances where a woman may consider egg freezing include;

• Those who are not ready now, but plan to have children in the future.
• Those who are yet to meet the right partner, but plan to have children in the future.
• Women about to receive radiation and/or chemotherapy for cancer; such treatments can harm the eggs or induce ovarian failure.
• Women with certain diseases (eg. ovarian cancer, cyst) that can cause premature ovarian failure.
• Women with a history of ovarian surgery.
• Women with genetic problems that accelerate the deterioration of the ovaries.
• Women who are predisposed to early menopause.
• Women undergoing in vitro fertilization and desire to store some unfertilized eggs for future use. 

How does egg-freezing work?

The egg freezing process commonly comprises three steps:

1. Ovarian Stimulation

Starting on the 2^nd or 3^rd day of a woman’s menstrual cycle, she will meet with her doctor to receive blood tests and an ultrasound. If the results of the tests are positive for potential success, the doctor will prescribe medicines to stimulate the woman’s ovarian follicles. Each follicle contains an egg, so it is basically stimulating egg production. This stimulation is an injection every day for 10-14 days. The woman will have a doctor consult every 3-4 days for further blood tests​  and transvaginal ultrasound to check her ovaries and follicle growth. Once the follicles are of a suitable size, the woman will receive a “trigger shot”, an injectable medication to complete the eggs maturity.  About 36 hours after the trigger shot, the doctor shall perform the egg retrieval.

2. Egg Retrieval

About 36 hours after the trigger shot, the doctor will sedate the woman, in order  to keep the process comfortable and painless, and using ultrasound imaging will guide a thin needle into the pelvic captivity and retrieve the eggs from the ovarian follicles.

3. Freezing

After the egg retrieval, the eggs will be specially washed, assessed, and the mature eggs will be frozen using a method called “vitrification”. This involves placing the eggs on a special device, freezing with ultra-rapid cooling technology, loading the device into a “straw”, and preserving the frozen eggs in liquid nitrogen until required in the future.

How safe is egg freezing for the eggs?

After being vitrified, a process that ultra-cools the eggs rapidly to stop any ice forming and harming the eggs, the eggs are stored in liquid nitrogen at less than -190 ºC. In theory the eggs can be stored indefinitely if held in a high-quality, well-maintained laboratory with consistent and regular quality control and monitoring of the liquid nitrogen and equipment, thus ensuring that the eggs remain in the same good condition. Nevertheless, it is important to note that pregnancy later in life will depend on several factors, such as the age of the eggs at the time of freezing, the age of the woman at the time of embryo transfer, the medical histories of the female and male partners, and the quality of the sperm.

How safe is egg freezing for the woman?

Although ovarian stimulation and egg retrieval are relatively safe procedures, no medical treatment is without risks. The processes of ovarian stimulation and egg retrieval can induce complications such as Ovarian Hyperstimulation Syndrome (OHSS), bloating and stomachaches, internal bleeding after egg retrieval, weight gain, and mood swings. The complications are typically minor and non-life-threatening, and a good doctor and clinic will monitor the cycles closely to minimize or avoid such complications.

What is the success rate of egg freezing?

The chances of becoming pregnant after egg freezing, thaw, fertilization and embryo transfer, depends on the number of retrieved eggs, the age of the woman at the time of egg retrieval (the recommended age is 20-35 years), the quality of sperm, as well as the quality of the freezing and thawing technique. Using the current vitrification techniques, 90–95% of frozen eggs can be successfully thawed.

The number of eggs retrieved per stimulation cycle will vary based on the age of the woman, her basal antral follicle count, and her hormone profile. For women who are younger than 35 years old, the number of mature eggs retrieved is typically about 10 to 15 eggs per one cycle, with this number usually decreasing when older than 35. The average chance of a pregnancy is about 7% per mature egg frozen.

As mentioned, a successful pregnancy using frozen eggs is not guaranteed, it is not 100%. Similar to getting pregnant naturally, successfully getting pregnant depends on various physical and genetic factors of both the female and male partners. The egg freezing technique is a process to preserve and store good-quality eggs, to preserve the potential of a pregnancy in the future.

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