Are fresh or frozen eggs better in Assisted Reproductive Therapy (ART)?

Fresh eggs were preferred over frozen eggs for use in assisted reproductive therapy (ART) until recently, and are still the most prevalent choice. However, advances in the methods used to freeze and thaw eggs have resulted in frozen eggs becoming a more viable option, with studies and fertility clinics reporting excellent pregnancy and live birth results with frozen eggs.

In this article, we look at the technology that is driving the success of frozen eggs, the results and benefits of using frozen eggs, what the egg freezing process entails, and where to turn to find the right option for you.

It has been almost 40 years since the first frozen egg birth was reported in 1986. However, frozen eggs took a fairly long time to become generally accepted, because its initial success rate was poor, due to the conventional “slow” egg freezing techniques used at the time. These techniques resulted in ice crystals forming inside the eggs, which damaged the eggs and also compromised their survival.

Thanks to scientific advancements in egg freezing technology, these egg freezing challenges have been resolved, and today frozen eggs produce success rates comparable to fresh eggs, while also offering other advantages.

Egg freezing advancements

Two egg freezing technology advancements have resolved the original challenges with frozen eggs.

One is the development of a new culture media system that protects the egg from damage during the egg freezing and thawing processes, and the other is ultra-rapid freezing, also called vitrification.

In brief, the new culture media system dehydrates eggs during egg freezing. This minimises the formation of ice crystals during the egg freezing process. The media also rehydrates the egg during thawing.

Ultra-rapid freezing or vitrification also prevents ice formation that would otherwise damage the eggs. At Cape Fertility, we use the Cryotec vitrification system. The Cryotec method is a highly simplified vitrification protocol but ensures a very high survival rate for frozen eggs.

As a result of these advancements that eliminate both previous impediments to safe egg freezing, it has become more “mainstream” since the late 2000’s.

Frozen eggs deliver solid results

According to scientific publications, there is no significant difference between frozen and fresh donor eggs in terms of the final blastocysts (early stage of an embryo) or pregnancy outcome.

In fact, a decade ago, the American Society for Reproductive Medicine (ASRM) published guidelines noting that egg freezing and thawing should no longer be considered experimental. The ASRM report reviewed almost 1000 published studies about egg freezing and concluded that sufficient studies have been done to warrant considering egg freezing as a clinically available technique, due to improved freezing and thawing techniques.

In addition, ASRM stated that no increase in chromosomal abnormalities, birth defects, or developmental deficits have been noted in the children born from frozen eggs to date.

Frozen eggs not only match fresh eggs in terms of success rates but also offer other benefits.

Egg freezing provides women a good option to preserve their fertility, with success rates comparable to standard IVF.

In addition, for those who need an egg donation, the success of frozen eggs means that egg banks are now a reality, providing the intended parents with a wider variety of options when considering the best egg donor. In addition, frozen eggs reduce the often-long waiting time for fresh donor eggs.

Furthermore, using fresh eggs in ART requires a great deal of coordination between the egg donor, the recipient of the egg donation and the fertility clinic’s medical team, which opens the door to many potential problems with regard to the tight timing requirements. For example, the cycles of the egg donor and the recipient must be synchronised using medication when fresh eggs are used. On egg retrieval day, the sperm required for fertilising the fresh eggs may not be received on time, or there may be a technical problem or an external challenge such as a power outage. Frozen eggs allow more time and opportunity to deal with any eventualities.

What the egg freezing process entails

The egg freezing process spans around two weeks. At Cape Fertility, we have streamlined the process of egg retrieval, preservation and protection, into five simple steps, which are briefly detailed below.

1: Evaluating Egg Reserves – When you first meet with us, one of our expert fertility specialists will provide a thorough fertility examination and help you determine your ovarian (egg) reserve – or how many good quality eggs are left in your ovaries. This is done with a normal ultrasound of your ovaries, as well as by measuring your level of two different hormones: FSH and AMH. With the ultrasound, the number of resting eggs in the ovaries can be estimated and an image of the uterus can also be observed. With a blood test, performed following the first few days after starting a new menstruation cycle, the levels of the two hormones can be measured.

2: Ovarian Stimulation – Before your eggs are retrieved for freezing, your fertility specialist will provide you with medication to improve the number of eggs that can be retrieved. The medication is administered through injections from the third day of a new menstrual cycle and are taken for 10 to 12 days. These are very easy injections to give yourself and not painful at all. During this time, your fertility specialist will do several ultrasound examinations to determine the best time to retrieve your eggs.

3: Egg Retrieval – Egg retrieval day is usually around day 14 of your cycle. The egg retrieval procedure is a quick and painless operation under sedation, and is performed at Cape Fertility’s purpose-designed premises. No hospitalisation is necessary, and the procedure only takes about 30 minutes. You will not experience any pain during the procedure – there is no cutting, stitches or scarring. Although you can be discharged after two hours, you will need to take the day off work.

4: Egg Freezing – After your eggs are retrieved, they are prepared in our laboratory under the care of one of our highly qualified embryologists, who will evaluate the appearance of the eggs and begin the process of preparing the eggs for freezing. Cape Fertility uses the latest culture media system and the advanced Cryotec vitrification system to ensure the survival rates of your frozen eggs are very high and much better than standard vitrification systems.

5: Egg Storage – Your frozen eggs are then safely stored in the laboratory in a liquid nitrogen container at a temperature of -196 degrees Celsius, until you are ready to use them.

Where to find the right option for you

For more than a decade, Cape Fertility has offered egg freezing as a viable option for women to preserve their fertility. Your care is our priority and attention to your medical safety is our primary concern. Our specialist team will take great care of you every step of the way.

If you have any questions about frozen eggs in ART, or if you want to know more about freezing your eggs, we invite you to contact us by clicking here…

At Cape Fertility, we value each individual person and we look forward to providing you with our signature individualised and personalised care when you have eggs retrieved, frozen and stored in a friendly, relaxed and caring environment at our advanced, purpose-built facilities in the beautiful city of Cape Town.