If you are one of the increasing number of women considering egg freezing, whether for medical or social reasons, this IVI blog article is here to help you make an informed choice. It takes a look at questions surrounding potential side effects and any risks from egg freezing.

There are two aspects to the question of risk around freezing eggs for future fertility. The first is whether there is any risk to the patient – you – of complications or side effects from the egg retrieval process. The other is about the risks connected with the survival of the eggs and any potential for damage to the future foetus, as well as how the results of IVF following egg freezing compare with overall IVF success rates. We also explain how we at IVI employ advanced techniques and technology to minimise risk and maximise success.

Why freeze eggs

There are lots of reasons why women would want to take advantage of the technology that is now available to preserve their fertility. These include:

• Women who want to delay parenthood for social, economic or relationship reasons and who know that their best chance is to freeze their eggs before their fertility starts to decline after the age of about 35.
• People diagnosed with cancer or other diseases who are facing treatment such as chemotherapy or radiotherapy which could damage their fertility.
• Transgender people transitioning from female to male, who may wish to preserve their fertility before starting hormonal or reconstructive surgical treatment, both of which could damage future fertility.
• Women in dangerous occupations which put them at risk of injury or death, for example military personnel being deployed to a war zone.

Complications of freezing eggs for the patient

The ovarian stimulation required before collecting oocytes for preservation is exactly the same as for normal IVF. The only difference is that the eggs are preserved, rather than fertilised, after retrieval. The more frequent side effects of the hormonal treatment are similar to the side effects of the menstrual cycle more generally. These include mood swings, bloating, breast tenderness or headaches and insomnia.

The hormonal treatment carries a small risk of causing ovarian hyperstimulation syndrome with symptoms ranging from dehydration and bloating to blood clots. There are also the slight risks associated with any medical intervention, for example bleeding caused by an injection needle and the risks of anaesthesia. These minor risks can however be minimised by a practitioner or clinic experienced in such procedures.

There is a final freezing eggs fertility risk that women thinking about this course of action may not have considered, and this is the potential for emotional difficulties in the face of disappointment. The use of frozen eggs implies to undergo an IVF treatment to use them in the future and does not guarantee a successful pregnancy as a final result, although as with all IVF, the odds, after a few cycles, are good and improving all the time. But because the emotional investment in the egg retrieval process can be quite intense, it is often a good idea to arrange for counselling specifically to help you to consider how you would deal with disappointment if it were to happen, at the same time as the treatment. At IVI, we offer psychological support every step of the way.

Risk to egg survival

Eggs which are frozen have a slightly lower chance of an eventual successful pregnancy than frozen embryos, since the possibility of causing damage makes it impossible to test eggs for viability before freezing. However, techniques are improving all the time. The earliest method was ‘slow freezing’ but now most clinics use a process called vitrification in which specific vitrification media solutions are used and eggs are frozen quickly in liquid nitrogen. A study carried out by the American Society for Reproductive Medicine in 2009 found that slow frozen eggs had a 61% survival rate compared with an overall 91.8% survival rate for vitrification.

There are several different vitrification protocols and at IVI we use one which demonstrates even higher success rates. We use the Cryotop method which has the best results, with around 97% of oocytes surviving the vitrification process for patients up to 35 years old, with an eventual pregnancy rate of 65% and we are the European leaders in the clinical use of this method. In addition, there is no evidence that there is more risk of birth defects or abnormalities for a pregnancy resulting from the use of frozen eggs than when fresh or frozen embryos are used.

What are the chances of success with frozen eggs?

The same reproductive prognosis applies for women who have had their eggs vitrified as their prognosis at the time of vitrification. There is therefore no loss of potential fertility. We did however find in our research that the best results are obtained when women have their eggs vitrified before the age of 35. To find out more, have a look at our findings about successful fertility preservation.

How IVI minimises risk:

At IVI we are dedicated to continuous research and development of new techniques in assisted reproduction, leading to even greater success. An example is the implementation of the Cryotop vitrification method, but there are many others and we have a record of over 1,900 scientific research publications focused on solving problems around infertility. Above all, our dedicated medical teams bring an unparalleled level of expertise and experience to our procedures. To learn more about how the process works at IVI, have a look at the video on our YouTube channel about the vitrification of oocytes.

The evidence is in the results: a cumulative pregnancy rate per IVF cycle on the first attempt (and of course this will be the final step after egg freezing, no matter how long the interval) of 71.3% for women using their own eggs, whether fresh or frozen, rising to 95.2% on the third attempt. If you think this could be the right way forward for you, go ahead and get in touch with us at IVI.