Over the last 30 years the average age of women becoming mothers for first time has consistently increased and this trend is expected to continue. 

For the first time in history women in their 30s are more likely to have kids than women in their 20s. This coincides with the larger demographic trend of women delaying childbirth to focus on their career progress. 

These changes, despite reflecting a socially driven lifestyle can adversely affect the reproductive potential in women. 

It has been well established that maternal age is a key-factor in fertility. Women are most fertile in their 20s. Thereafter, their fertility reduces gradually, particularly after the age of 35 and dramatically after the age of 40. This decline is attributed to the reduction in both the quality and the number of the remaining eggs to the ovaries. 

Recent development of advanced techniques in Assisted Reproduction enables us to “freeze time”Egg freezing refers to a method of storing a woman’s eggs for future use if required. This treatment option does not require a sperm since no fertilisation takes place. The main advantage of egg freezing is that it maintains the quality of a woman’s eggs at the age they were frozen. Based on scientific evidence freezing does not affect egg quality. These eggs can be used in the future offering a better chance of a successful pregnancy. 

Nowadays egg freezing for social reasons has become very popular. Tech companies like Apple, Facebook, and Google are offering employees free egg freezing. This policy is supposed to provide employees a freedom of choice to pursue family planning consistent with their own timeline.  

It is vital to acknowledge that although from a social perspective, egg freezing may provide women the peace of mind of a possible “fertility insurance policy” there is no guarantee of achieving a pregnancy in the future.  

Egg freezing was initially developed to help women undergoing cancer treatment that could potentially impair their fertility. However in recent years increased demand has been observed among healthy women to preserve their fertility for social reasons.  

Egg freezing can be beneficial for women wishing to preserve their fertility for the future and can be considered for a variety of reasons: 

  • Women with cancer about to begin chemotherapy or pelvic radiotherapy. 
  • Women with a family history of premature menopause. 
  • Women at risk of premature ovarian insufficiency due to the presence of certain chromosomal abnormalities such as Turner syndrome or fragile X syndrome.
  • Women who wish to postpone having a child for professional, social or purely personal reasons. 
  • Couples with ethical objections to freeze and store embryos.  

The main benefit of egg freezing is that it preserves the quality of a woman’s eggs at the age they were frozen. Clearly, the younger you are, the quality and quantity of your eggs are higher and therefore, if you need to use them in the future the chance of success would be higher. 

Despite the decline in both egg quality and quantity with age, there are drawbacks to both freezing too early or too late.  

It is reasonable to assume that if you freeze your eggs at a very young age it is less likely you will ever need to use them in the future, as the possibility of a natural pregnancy would be higher. 

In contrast, waiting to your late 30s or early 40s would allow you more time to start a family naturally, however the expected success rate of egg freezing at this point will be much lower. 

If you are single and you are not planning to imminently start a family the ideal time to freeze your eggs is in your late 20s to mid 30s. However older women could also benefit from egg freezing depending on their social circumstances and their hormonal profile. 

So in summary, although we appreciate that it is a difficult balance between any social benefit and the physical, emotional and financial burden of treatment, you should consider that the longer you wait the lower the chance of having a successful outcome would be. 

The egg freezing process involves the following steps:  

STEP 1- Ovarian stimulation

Stimulation of the ovaries with hormones known as gonadotrophins is usually required for a period between 10 to14 days. The hormones are in the form of self-administered subcutaneous injections and need to be taken daily. The aim is to stimulate the ovaries produce multiple follicles simultaneously. Your response to the hormones is monitored very closely with daily hormonal blood tests and ultrasound scans on alternate days, to pick up the slightest changes, which will impact on the choice of medications and timings of treatment. Medications may be altered and dosages may be changed if required. This level of monitoring may be inconvenient in the short term, but we believe it is vital and can make the difference in the quality of the eggs you produce. This approach in treatment is strictly individualized and it is this attention to detail and dedication that contributes to excellence in results.  

When the follicles in the ovaries reach the appropriate size we plan your egg collection. A trigger injection is given approximately 36 hours before the egg collection. The exact timing of the trigger injection and the egg collection is essential for the optimal outcome with regards to the egg quality and quantity. 

STEP 2- Egg collection 

On the day of the egg collection you need to present at the clinic in the morning, having had nothing to eat or drink from midnight the night before your procedure. Nail polish, make-up, jewellery and contact lenses should be removed prior to coming in. Prior to moving to the operating theatre you will be reviewed by the cardiology and the anaesthetic team and you will be asked to sign the relevant consent forms. 

Egg collection is a day case procedure, which usually lasts for approximately 20 minutes and is performed under light sedation. With the use of a fine needle under ultrasound guidance, the fluid in the follicles in each ovary is aspirated and the eggs are obtained.  

Following the procedure you will be given antibiotics and painkillers and you will be taken to a recovery room to rest, for approximately 2-3 hours. Once you are fully awake and able to eat, drink and pass urine, you will be able to leave the clinic. You are strongly advised to arrange for someone to drive you home and avoid driving for 24 hours. 

STEP 3- Egg freezing 

Following collection the cells around the eggs are stripped away to identify which eggs are mature. These mature eggs are then stored in liquid nitrogen containers (-196oC), using the vitrifcation technique, which is the best available method of freezing. Vitrification allows for ultra-fast freezing of the eggs with exceptional egg survival rates. 

 STEP 4- Future use 

When the woman desires, these eggs are thawed and fertilised with the sperm using micromanipulation techniques (ICSI). 

ICSI (injecting the sperm into the egg) rather than IVF (mixing the sperm and the egg) is required to assist the sperm penetrate the egg, as the freeze/ thaw process makes the outer layer of the egg tougher. 

The following tests are required:  

  • Anti-Mullerian Hormone (AMH)- (within 1 year of treatment) 
  • A full hormone profile done between the 2nd – 3rd day of your period (within 1 year of treatment). That would include the following hormones: FSH, LH, Oestradiol (E2) and Prolactin 
  • FBC (within 2 months of treatment)  
  • Mammogram – if aged 40 years or above – In view of the increased prevalence of breast disease we would recommend screening prior to commencing a treatment (unless one has been performed within the last 3 years). 

Furthermore the following blood tests are mandatory for you and need to be done within 6 months of the treatment: 

  • HIV  
  • Hepatitis B surface antigen (HBsAg)  
  • Hepatitis C (Anti-HCV) 
  • Syphilis 


Egg is the largest human cell consisting mainly of water. When it is cooled it forms crystals that can destroy it. Technology used in egg freezing has improved greatly over the past few years. The older less effective “slow” freezing technique has been replaced by vitrification, a new ultra- fast freezing technique that inhibits the ice crystal formation within the cell and therefore limits the damage during the freeze/thaw process. The frozen eggs are subsequently stored in liquid nitrogen containers (-196oC). 

Vitrification has made a real difference in the egg freezing process and is associated with exceptional egg survival rates. 

According to the Greek law the standard storage duration for eggs is any period up to 10 years. There is an annual fee for storage of eggs.  

It is also important to know that the Greek law permits fertility treatment (all kinds) for women up to age 50

Egg freezing remains a relatively new type of treatment. Even though many thousands of women have their eggs frozen, the number of women coming back to thaw and use their eggs is still limited.  

Increasing worldwide data is suggesting that frozen eggs may be as effective in achieving a pregnancy as fresh eggs. 

Clearly, at a younger age, the quality and quantity of the eggs are higher therefore associated with higher success rates. 

Based on your age, your hormone profile and your medical history, Dr Diamantopoulos will discuss and explain your projected success rate. 

Some women do experience side effects from the fertility drugs they take during the stimulation, which are usually mild. The most common side effects include a local reaction at the injection site, dizziness, mood swings, hot flushes and feeling bloated. 

In approximately 10% of cases a smaller than expected number of eggs will be collected and in about 1% of cases no eggs will be retrieved.  

Frozen eggs may be stored for many years without deterioration in their quality. Increasing worldwide data are suggesting that frozen eggs may be as effective in achieving a pregnancy as fresh eggs. With the use of the vitrification fast-freezing technique approximately 90% of eggs survive the thawing process, although this varies with age and older women have lower egg survival rates. Subsequently the defrost eggs can achieve fertilization rates, in the range of 70%-80%, which are similar to the fertilization rates seen with fresh eggs. However, very rarely the eggs do not survive the thawing process or none is fertilised.  

Egg freezing is a not a guarantee for children in the future. A non-intended social consequence is the false sense of security that may lead some women to a detrimental delay in trying naturally for a baby. In case that treatment with the frozen eggs is unsuccessful, women may face the prospect of trying for a baby at a much older age when the chances of a successful outcome would be significantly reduced. 

Many women are concerned whether the hormones administered during the stimulation process of the ovaries can cause malignancies and, specifically, breast cancer. This is a myth, which has not been proven to be true. According to large epidemiological studies, conducted worldwide, including hundreds of thousands of women there is no difference in the incidence of breast cancer between women who took and those who didn’t receive hormones during fertility treatments. 

Nevertheless, hormones should be used cautiously and women should receive the “right” amount rather than take excessive dosages of the hormonal drugs. 

A common misconception is that egg freezing or IVF treatment may reduce the number of the remaining eggs in women. That is not true. 

In a natural menstrual cycle, a number of follicles containing eggs are recruited from the stores in the ovaries, in response to the natural Follicle Stimulating Hormone (FSH) and initially all begin to grow. However only one follicle becomes the dominant follicle, continues to grow and is the one that ovulates and releases the egg within it, while the rest of the follicles regress. 

In a stimulated IVF or egg freezing cycle the administration of hormonal (FSH containing) injections makes the above process more efficient by stimulating simultaneously multiple follicles to continue growing, thus allowing the collection of as many eggs as possible. Those follicles are not any more than those already recruited through the natural process. 

Therefore there is no long-term adverse implication to the fertility potential or any risk of earlier menopause.