2 February 2016

The big freeze

The big freeze

The topic of egg freezing (oocyte cryopreservation) has recently dominated the news agenda, with reports that the demand for the procedure has quadrupled in the past year1. Large corporations such as Apple and Google have now added egg freezing for career focussed women to their company benefits, and popular celebrities such as Kim Kardashian, Khloe Kardashian and Lady Victoria Hervey have spoken openly about their own plans for fertility preservation.

World-leading fertility group clinic IVI Fertility, has noted a direct impact on their patient numbers following the attention on egg freezing throughout 2015, and has recorded a 46 per cent increase in the number of women requesting to have their eggs frozen for social reasons.

While it is undoubtedly positive that increasing numbers of women are thinking about preserving their fertility as they become more and more fertility aware, it is also important that women are fully educated on the serious nature of the procedure, and what steps the treatment involves.

The IVI Group is a European leader in assisted reproduction and to date has helped over 100,000 children to be born all across the globe. With 40 clinics, in 10 different countries, IVI are pioneers within the fertility industry and are at the forefront of medical development and advancement within the field.

Here, fertility specialist Dra Gemma Castillón from the IVI Fertility Clinic in Barcelona shares her expert insight on the things every woman should know before making the decision to freeze their eggs.

What is ‘egg-freezing’?

Dra Castillón Says: “Egg Vitrification – more commonly known as ‘egg-freezing’ – is a technique used to preserve a woman’s fertility. More specifically, egg freezing is when a woman’s eggs (oocytes) are extracted, frozen and stored away. Later, when she is ready to become a mum, the eggs can be unfrozen, fertilised, and transferred back into the uterus as embryos through a process called IVF (In-Vitro Fertilisation). The main benefit of egg freezing is that it allows a woman’s reproductive capacity to be postponed.”

Who should consider egg-freezing?

Dra Castillón Says: “Due to a new generation of career-driven women, more and more couples are making the decision to try for a baby later in life. However the chances of falling pregnant will decrease the older you get. Women who want to delay pregnancy in order to pursue a career or other personal goals should therefore opt for egg freezing.

Oocyte cryopreservation is also beneficial for women who have developed conditions or illnesses which have stopped them having a child such as developing cancer3. This allows women to postpone pregnancy until they have recovered, or are healthy enough to have a baby. IVI has had a specific program in place since 2007 to assist with this, which to date has resulted in 8 babies being born, and another 6 pregnancies currently in progress

Any woman contemplating egg freezing needs to understand that it’s a very important first step towards becoming a mother. It is vital that women consider the psychological and social impacts of egg freezing, and make sure that they aren’t rushing into a decision. On the other hand, it’s also important that they don’t delay making a decision for too long and risk their chances of achieving a successful pregnancy. Egg freezing also offers a great solution for women who may be facing motherhood alone and want to think about their future, whilst at the same time maintaining their current lifestyle.”

When is the best time to freeze your eggs?

Dra Castillón Says: “At IVI, we recommend that women should ideally freeze their eggs before the age of 38. The younger the patient, the better the survival rate of the eggs, and therefore, the higher the pregnancy rates. This is considered to be a woman’s prime reproductive years, and so the eggs are of a premium quality and quantity.”

What does the egg-freezing process entail?

Dra Castillón Says: “Egg freezing is essentially a solidification process. Firstly, patients need to undergo daily subcutaneous injections to help stimulate the follicles and make sure that mature eggs will be collected. Eggs are ‘collected’ from the woman’s ovary through the vagina, under anesthesia, and guided by ultrasound. Once removed, they are treated with cryoprotective substances to protect them from freezing damage. Following this, the eggs are vitrified (frozen) by being submerged in liquid nitrogen at a temperature of -196°C. They are then stored in liquid nitrogen in a secure environment, until the patient is ready to conceive.

Patients should be aware that egg-freezing does not guarantee pregnancy. The success rate varies according to patient’s age.

Of the different vitrification techniques that are available, the ‘cryotop’ method is the newest and the one with the best results. IVI Fertility pioneered this technique, and is in fact the European leader in its clinical use.

The cryotop method is an open vitrification system which consists of a rapid cooling and warming of the oocytes/embryos while embedded in very small volumes of highly concentrated cryoprotector. Compared to slow freezing methods, this technique has raised oocyte survival rates by up to 90%, and nowadays thanks to the cryotop method pregnancy and implantation rates are comparable to the ones using fresh cycles.

How long does the egg-freezing process take?

Dra Castillón Says: “A lot of people are misguided in their belief that egg freezing is a simple case of walking into a clinic, having your eggs removed, and walking out again. This is certainly not the case, and on average will take 13 days from the first day of ovarian stimulation to the ‘collection’ of the eggs. Before the process begins, patients are asked to take regular blood tests and complete ultrasounds to confirm that they are a good candidate to have their eggs frozen. One day after the retrieval procedure, we will be able to tell how many eggs collected are healthy and mature.”


  • Ricardo Pedrós
  • Lucía Renau
  • Email: prensa@ivi.es
  • Phone number: (0034) 96 317 36 10
  • Calle Colón, 1 - 46004 (Valencia)


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February 2020

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