Is egg freezing right for you?

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In principle, egg freezing sounds simple enough – have some eggs collected, freeze them for storage, then thaw them when you’re ready to undergo fertility treatment – providing you with a chance to store your eggs while you’re still young and beat the biological clock. But what exactly does egg freezing involve and are you an appropriate candidate?

Why freeze your eggs?

You may want to consider freezing your eggs if you’re worried about your fertility declining but your life circumstances mean that you’re simply not ready to start a family. Alternatively, you may have a medical condition or be receiving medical treatment that could affect your fertility. If you’re a female transitioning to a male, you may wish to preserve your fertility before starting reconstructive or hormonal therapy, which can lead to a loss of your fertility.

What does the egg freezing process involve?

The first stage of egg freezing is ovarian stimulation, which involves 10–14 days of hormone injections to stimulate your ovaries to produce multiple eggs. There are various techniques used for stimulation and your fertility specialist will decide, together with you, which is most suitable for you. The developing follicles, which contain your eggs, are monitored by ultrasound and sometimes by blood hormone levels to determine when they are ready to be collected.

When mature, your eggs are collected (usually while you’re under sedation rather than general anaesthetic), frozen and put into storage. In most cases, frozen eggs can be stored for up to 10 years.

When you’re ready to have a baby, the eggs are then thawed and used in IVF treatment. This involves fertilising your eggs with sperm using a method called intracytoplasmic sperm injection (ICSI), whereby sperm is injected directly into the egg. The embryos are then grown in the lab for up to 6 days and then transferred to your uterus (womb).

Factors to consider when deciding whether to freeze your eggs

1. Success rates

Egg freezing is an established procedure. It has now been two decades since the world’s first pregnancy using frozen eggs and over this time, there have been notable improvements in the technology and processes we use. High rates of success can now be expected when circumstances are optimal. A 2017 study showed that freezing 20 eggs before the age of 35 gives a 90% chance of having a baby.1

When considering these statistics, it is important to note that the number of women who actually go on to use their frozen eggs is still quite low. In 2017–18, less than 1% of IVF cycles in Victoria involved the use of a woman’s own thawed eggs.2  The data on egg freezing success rates are challenging to compile because many women choose not to use their eggs for many years after freezing and some may not use them at all. Furthermore, current figures may not reflect advances in egg freezing technology because the results are from a period when clinics were using different ‘slow freezing’ techniques.

In terms of understanding the success rates for frozen eggs compared to ‘fresh’ (recently retrieved) eggs, a study published in the Journal of Human Reproduction in 2010 examined the success of IVF in 600 women, half of whom were assigned ‘fresh’ eggs while the other half were given frozen and thawed eggs.3 The study found no significant difference in pregnancy rates between the two groups of women, concluding that freezing eggs and thawing them for later use has no effects on success rates. According to these findings, the likelihood that your eggs will result in a pregnancy will be the same whether you choose to freeze and use them later or use them straightaway.

2. Age

The age at which you choose to freeze your eggs is key to your chances of having a baby – the younger you are, the better. Egg quality declines more rapidly after the age of 35, so the best time to freeze your eggs is in your 20s and early 30s.4 Unfortunately, eggs collected from older women are less likely to form viable embryos and are also less likely to successfully implant in the wall of the womb. Thus, if you decide to freeze your eggs when you are older, we typically need to collect more eggs to ensure at least one egg is of suitable quality to result in a baby. However, as women age, they also have fewer eggs, so only a small number of eggs may be available for collection and freezing. If this is the case, you may need more than one treatment cycle to collect an adequate number of eggs for storage.

Both the number and quality of eggs available for freezing are important, because at each step in the freezing and subsequent IVF process, there is a risk that some are lost. Of the eggs that are collected, some may not be appropriate for freezing, some may not survive the thawing process, and some may not be fertilised or successfully develop into embryos.

3. Costs

In Australia, fertility treatment is only covered by Medicare and other government subsidies when there is a medical need for the treatment. If you freeze your eggs for non-medical reasons (i.e. ‘elective egg freezing’), you won’t be eligible for Medicare assistance.

For detailed information about the costs associated with egg freezing, please visit our fees page.

*Does not include hospital fees; †Does not include medications or hospital fees.

What are the alternative options?

If freezing your eggs is not a suitable option for you, other potential options include:

When considering your fertility and the options for extending it, there is no one-size-fits-all approach. As with all aspects of fertility care, the best decision for you is the one that is personalised to your individual situation.

Learn more information about Newlife IVF’s egg freezing services. If you would like to discuss your options with one of our fertility specialists, please call Newlife IVF on (03) 8080 8933. Alternatively, you can book online via our appointments page.

References

  1. Munné S et al. Human Reprod 2017; 32(4):743–749.
  2. Victorian Assisted Reproductive Treatment Authority. Annual Report 2018.
  3. Cobo A et al. Human Reprod 2010; 25(9):2239–2246.
  4. Saumet J et al. J Obstet Gynaeocol Can 2018; 40(3):356–368.

 

 

Preimplantation genetic testing: an overview

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To help avoid this confusion and facilitate communication between fertility specialists, researchers and patients, a group of reproductive health organisations developed a standardised glossary of fertility-related terms and definitions.

This glossary includes recommendations for the terminology used to describe genetic testing of embryos. Previously referred to as PGS (preimplantation genetic screening) and PGD (preimplantation genetic diagnosis), all genetic testing on embryos is now known as PGT (preimplantation genetic testing).

The different types of genetic testing are differentiated by the addition of further letters to the PGT acronym: namely PGT-A, PGT-M and PGT-SR. To understand the meaning of these terms and the types of genetic testing they refer to, it first helps to understand some basics of genetics.

A brief lesson on genetics

You may have heard of the term ‘chromosome’ before. Chromosomes are structures that house our DNA, which is the genetic code that contains all the instructions required to make you, you! Normally, every cell in the body contains 46 chromosomes. These chromosomes are inherited – during fertilisation (when egg meets sperm), 23 chromosomes are passed on from each parent.

There are many different types of genetic errors that can occur, and a wide range of genetic conditions they can give rise to. One type of error is an abnormality in the number of chromosomes, which is referred to as aneuploidy. Instead of 46 chromosomes, a person may have 45 or 47 chromosomes, as seen in Turner and Down syndrome, respectively. Embryos that have an abnormal number of chromosomes are less likely to result in an ongoing pregnancy.

Small errors may also occur in the DNA contained within the chromosomes. These errors are known as genetic mutations and can give rise to diseases such as cystic fibrosis and haemophilia.

Lastly, errors can occur in the structure of the chromosomes, including changes to their size or how the DNA is arranged within them. This is not the same as aneuploidy – many people with structural rearrangements have a normal amount of DNA overall. If that is the case, the person will probably not be affected by the rearrangement. However, someone with a structural rearrangement has an increased risk of producing an embryo with an abnormal amount of genetic material, which is less likely to result in a healthy, ongoing pregnancy.

The different types of genetic testing

There are three different types of genetic testing that may be performed on embryos:

  • PGT-A (preimplantation genetic testing for aneuploidies): PGT-A used to be known as PGS. It is designed to identify the embryos that have an abnormal number of chromosomes (aneuploid embryos), as these embryos are less likely to result in an ongoing healthy pregnancy.
  • PGT-M (preimplantation genetic testing for monogenic or single gene defects): PGT-M was previously known as PGD. PGT-M assesses the embryo’s genetic code to determine if it contains mutations that may result in certain genetic conditions, such as cystic fibrosis or haemophilia.
  • PGT-SR (preimplantation genetic testing for chromosomal structural rearrangements): Like PGT-M, PGT-SR was also previously known as PGD. PGT-SR detects structural rearrangements in an embryo’s DNA and can detect whether the embryo has the correct amount of genetic material.

How do you know if genetic testing is appropriate for you?

Not all patients require PGT, and each type of PGT is only appropriate for particular groups of people. Your Newlife IVF fertility specialist can advise whether genetic testing is suitable for you. To make an appointment, call (03) 8080 8933 or book online via our appointments page.