What Is Egg Vitrification? – Advantages Over Freezing

By BSc, MSc (embryologist), BSc, MSc (embryologist), BSc, MSc (embryologist) and (invitra staff).
Last Update: 02/03/2020

Postponing the birth of the first child can lead to some trouble when trying to get pregnant at an advanced maternal age. For this reason, an increasing number of women with this desire opt for freezing their eggs, an option that allows them to have their eggs frozen for an indefinite period of time.

This treatment offers you the certainty that your eggs will maintain their quality and characteristics they had at the moment they were cryopreserved.


Egg vitrification or freezing is an Assisted Reproductive Technology (ART) that allows women to freeze their eggs for later use.

This process is not only a major advantage as a method for retaining female fertility, but also as a way of scheduling fertility cycles. It has allowed that, in cases where a particular fertility treatment cannot be performed, it can be posponed as long as there are frozen eggs to use.


The process for freezing eggs is divided, in general, into two different steps: on the one hand, egg harvesting, and on the other hand, egg vitrification.

The following are the particularities of each procedure:

Stimulation and egg collection

The first step when a woman decides to freeze her eggs is performing a hormone analysis in which the ovarian reserve is evaluated. A transvaginal ultrasound is also necessary to verify there are no unexpected alterations. Once these tests are done and the results show everything is working as it should, ovarian stimulation is scheduled.

To stimulate the ovaries, gonadotropins are administered. The purpose of this medication is to trigger the production of multiple follicles.

Ovarian stimulation may last longer than expected or the other way round, since it depends on each woman’s response to it. Follicle growth will be monitored throughout the process to readjust, if necessary, the protocol followed.

Finally, when the majority of the follicles have reached a 16-18 mm size, then follicular puncture will be carried out for egg retrieval.

Egg retrieval or ovum pick-up is a simple procedure whereby, with the aid of an ultrasound-guided needle, the eggs are punctured to retrieve the eggs they contain. The process typically lasts between 20 to 45 minutes and it is done using sedation so that the woman feels no pain at all.

Once the eggs are retrieved in the operating room, they are brought to the IVF laboratory, where specialists in Embryology will proceed with the vitrification process.


The process of egg vitrification is done using ultrarrapid cooling, hence the name vitrification. During this process, using a substance called cryoprotectant is crucial, since they prevent such low temperatures to damage the cells.

Technically, egg vitrification is a process whereby the eggs goes through the cryoprotectant substance and then is deposited in a special device used for freezing to, finally, immerse them in liquid nitrogen.

The most common device used to this end is called Cryotop, consisting of a fine strip of transparent film attached to a plastic handle that, via surface tension, attaches to the egg after having been processed with cryoprotectants.

When the process finishes, Cryotop is closed with a cap and stored in a liquid nitrogen tank for being cryopreserved at the egg bank.

As one shall see, this technique requires great expertise due to the fragility and tiny size of egg cells.

Treatment with frozen eggs

When the woman wants to use the cryopreserved eggs, the beginning of the treatment will be scheduled. Undergoing a fertility treatment is required, since eggs cannot be put back in the woman's ovaries after being retrieved. To this end, embryos are created in the lab, which will be transferred to her uterus.

The oocytes will be thawed and then microinjected through ICSI technique either using the partner’s own sperm or donor sperm.

Then, the embryos will be cultured. Only the highest-quality embryos will be transferred to the patient, who has to prepare her uterus for the embryo implantation.

A clinical hCG test will be done two weeks later (2WW) to check whether she is pregnant or not.

Get more info by clicking the following link: What Are Normal hCG Hormone Levels during Pregnancy?


It is known that women's ovarian reserve decreases exponentially with age. Over the years, follicular reserve and oocyte quality diminish; therefore, women who delay motherhood have to resort to donor eggs.

Freezing the own oocytes has many advantages, including:

Oocytes do not age
Egg cryopreservation allows for the eggs to maintain the same characteristics they had when they were frozen, without them being affected by the vitrification process at all.
Increased chance of success
since the oocytes used are those the woman produced at a younger age, their quality is better than that of those produced at an older age. This reduces the likelihood of miscarriage or chromosomal abnormalities in embryos.
Delated motherhood
It is the main advantage of this technique. By freezing eggs, many women make sure that, in the future, they will have the chance of having a biological child as long as they are still able to bear a pregnancy, since not only egg quality matters when it comes to achieving a pregnancy.
Simple procedure
Although certain complications can occur as a consequence of ovarian stimulation or side effects of fertility drugs, in general it is a simple, rapid procedure that can be highly helpful in the future.

This technique is not only indicated in cases of women who wish to delay motherhood but also among women who are about to start some kind of aggressive treatment such as chemotherapy. In these cases, they can preserve their fertility to have a baby once they have overcome this disease.

According to Rocío Díaz Giraldez, BSc, MSc:

Keeping in mind that eggs are cryopreserved in liquid nitrogen at a temperature of -196 °C, and they have all their biological functions retained, they can be cryopreserved for a long period of time, although it has not been scientifically determined yet.


The cost of egg vitrification, though similar, varies from country to country, as one shall see in the following sections:

Cost in the USA

In the United States, the process can be divided into two phases. First, the egg retrieval procedure, which can cost anywhere between $600 to $1,500. Second, the storage fees, which cost is $1,200 per year. At some fertility clinics, it is free for the first year.

If you are considering freezing your oocytes to have a baby in the future, we recommend that you get your Fertility Report now. In 3 simple steps, it will show you a list of clinics that fit your preferences and meet our strict quality criteria. Moreover, you will receive a report via email with useful tips to visit a fertility clinic for the first time.

Cost in the UK

As regards the freezing eggs in the UK, it might be NHS funded depending on the cause and where you live.

The following is the average cost of an egg freezing cycle according to the Human Fertilisation & Embryology Authority (HFEA):

  1. Egg collection and freezing: £3,350
  2. Medication: £500-1,500
  3. Storage fees per year (up to 10 years): £125-350/year
  4. Thaw cycle and embryo transfer: £2,500
  5. TOTAL COST: £7,000-8,000

According to the HFEA, if you have a medical condition or need treatment for a medical condition that will affect your fertility, NHS funding may be available.

On the contrary, if you are worried about your fertility declining but have no medical condition, then it is called elective egg freezing and NHS funding is not available for these cases.

Cost in Canada

In Canada, the initial egg collection procedure typically costs between $6,000 and $8,000 CAD. To this, we should add the cost of hormones and medications, which can range from $3,000 to $6,000 CAD on average.

The annual storage fee is $350 CAD approximately.

FAQs from users

Is there an age limit on egg freezing?

By Sara Salgado BSc, MSc (embryologist).

In principle, there is no age limit on egg freezing; a woman can decide to do it whenever she wants. However, one should consider preserving her fertility at a young age, as egg quality is better at this point. This, at the same time, translates into higher chances of getting pregnant in the future by means of IVF.

How much does egg freezing cost?

By Victoria Moliner BSc, MSc (embryologist).

The average price of egg vitrification is usually between $10,000 and $18,000. However, it still depends on each fertility center. It should also be taken into account that hormonal medication for ovarian stimulation is not included in this budget and can cost between 500 and $1,000. Finally, after the first or second year of freezing, fertility clincis usually require that a maintenance fee of around $ 5-600 per year be paid for the frozen eggs.

Which is better, egg or embryo vitrification?

By Victoria Moliner BSc, MSc (embryologist).

The truth is, there is no treatment better than other, since in both cases the survival rate after the thaw procedure is above 90% and the quality of both eggs and embryos is usually the same.

The decision between one option or the other depends on your personal decision and the advice of your doctor. If you are single at the moment of vitrification, you might wish to opt for egg vitrification only.

When is egg freezing indicated?

By Zaira Salvador BSc, MSc (embryologist).

The main indication of egg vitrification is to postpone motherhood. However, there are other very important indications, such as preserving fertility in the following cases:

  • Women who are going to undergo aggressive treatment such as chemotherapy so that they can become mothers once they have overcome the disease.
  • Women who have received or will receive some type of surgery on the ovaries, as in the case of endometriosis for example.
  • Women who are going to have their ovaries removed due to a tumour.

Does egg freezing hurt?

By Zaira Salvador BSc, MSc (embryologist).

In order to freeze the eggs, women need to go through a process of ovarian stimulation and follicular puncture. These procedures can be uncomfortable because they must take hormonal medication and then undergo surgery to remove the eggs. However, unless there are any complications, it is not painful.

Suggested for you

Throughout this post, we have explained what is the egg vitrification process about from a technical perspective. If you want to learn more about fertility preservation, click here: Fertility Preservation – Cost & Options for Retaining Your Fertility.

On the other hand, if you wish to get more info on the sperm freezing process as well, we recommend that you read: What Is the Process of Freezing Sperm?

We make a great effort to provide you with the highest quality information.

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Alberto Reche y Manuel Martínez Moya. Preservación de la fertilidad. Manual de Buena Práctica Clínica en Reproducción Asistida (pp. 115-131). Sociedad Española de la Fertilidad

Colomé C, Carrasco M, Agramunt S, Checa MA, Carreras Collado R. Fertilidad en mujeres mayores de 40 años. Ginecología y Obstetricia Clínica. 2008.

ESHRE Task Force on Ethics and Law. Oocyte criopreservation for age related fertility loss. Human. Reprod. 2012.

Fertility Assessment and treatment for people with fertility problems. NHS. NICE clinical guideline 156. February 2013.

Glujovsky D, Riestra B, Sueldo C, Fiszbajn G, Repping S, Nodar F, Papier S, Ciapponi A. Vitrification versus slow freezing for women undergoing oocyte cryopreservation. Cochrane Database of Systematic Review 2014, Issue 9. Art. No.: CD010047.

Human Fertilisation & Embryology Authority (HFEA) (2018). Should I freeze my eggs? A guide to the latest information and statistics on egg freezing in the UK. See

Reproducción Asistida ORG. Video: ¿Durante cuánto tiempo pueden mantenerse los óvulos criopreservados? (How long can frozen eggs be stored?), by Rocío Díaz, BSc, MSc, Oct 25, 2016. [See original video in Spanish].

Sociedad Española de Fertilidad (SEF) (febrero de 2012). “Saber más sobre fertilidad y reproducción asistida”. En colaboración con el Ministerio de Sanidad, Política Social e Igualdad del Gobierno de España y el Plan de Calidad para el Sistema Nacional de Salud.

FAQs from users: 'Is there an age limit on egg freezing?', 'How much does egg freezing cost?', 'Which is better, egg or embryo vitrification?', 'When is egg freezing indicated?' and 'Does egg freezing hurt?'.

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Authors and contributors

 Rocío Díaz Giraldez
Rocío Díaz Giraldez
BSc, MSc
Bachelor's Degree in Biology and embryologist specialized in Reproductive Medicine. Several years of experience working in embryology laboratories. Currently, she is the lab director of YES! Reproducción in Seville, Spain. More information about Rocío Díaz Giraldez
 Sara Salgado
Sara Salgado
BSc, MSc
Degree in Biochemistry and Molecular Biology from the University of the Basque Country (UPV/EHU). Master's Degree in Human Assisted Reproduction from the Complutense University of Madrid (UCM). Certificate of University Expert in Genetic Diagnosis Techniques from the University of Valencia (UV). More information about Sara Salgado
 Victoria Moliner
Victoria Moliner
BSc, MSc
Degree in Biochemistry and Biomedical Sciences from the University of Valencia (UV). Master's Degree in Biotechnology of Human Assisted Reproduction from the UV and the Valencian Infertility Institute (IVI). Presently, she works as a Research Biologist. More information about Victoria Moliner
Adapted into english by:
 Romina Packan
Romina Packan
inviTRA Staff
Editor and translator for the English and German edition of inviTRA. More information about Romina Packan

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