Professor Dr Geeta Nargund, Medical Director of CREATE Fertility
Barely a week goes by without stories in the national papers about egg and embryo freezing, the majority of which appear to be critical. The freezing of eggs has been disregarded by some as less effective when compared to using fresh eggs, due to sensationalised headlines supported by historic data and conclusions based on old method of “slow freezing”. The published scientific papers show encouraging results with the modern vitrification technology and this can be reassuring for those hoping to take a control over their fertility and seek the latest options.
A newer method has been used for a number of years now and has proven success rates, so why are women unaware of it? A ground breaking new study, published earlier this month, shows that frozen embryos are just as likely to result in a live birth as fresh ones from stimulated IVF cycles. This data led by Chinese researchers, highlights the success of the vitrification, the latest freezing method; a faster freezing process that causes less damage to eggs and embryos than the historic slow freezing process.
The research was published in the New England Journal of Medicine shows that the live birth rate did not differ significantly between fresh- embryo transfer and frozen embryo transfer among ovulatory women with infertility, but frozen-embryo transfer resulted in a lower risk of Ovarian Hyperstimulation Syndrome (OHSS). This is no surprise for those of us in the scientific field. The ideal choice should be to use mild stimulation for IVF to reduce the risk of the complications such as Ovarian Hyperstimulation Syndrome (OHSS). Mild IVF focuses on collecting fewer eggs of higher quality, compared to high stimulation conventional IVF, which is aims to collect as many eggs as possible. Mild stimulation IVF allows fresh embryo transfer to take place with better health outcomes for the woman and baby without the need for freezing all embryos. In conventional high stimulation IVF where high numbers of eggs are collected, there is an increased risk of OHSS for the woman as well as an increased risk of low birth weight and prematurity in babies from fresh embryo transfer. In such treatment cycles, a “freeze all embryos” policy is widely used to prevent complications.
This data hopefully goes some way in reassuring women and couples who may need to freeze embryos. The freezing technology has moved on and success rates have significantly improved, so the advice and information that we provide as fertility specialists must reflect this.
Vitrification methods are now widely used and have a proven track record, particularly when it comes to egg freezing. With around 80% survival rate of frozen eggs, this new and advanced procedure significantly increases the likelihood of having a baby from frozen-thawed eggs in the future. We need to provide women and couples with options, helping them to understand the recent technological advances and how vitrification methods can aid in their fertility journey. This is particularly important considering that so many are simply priced out of the private fertility treatment market. This research into embryo freezing is a step in the right direction.
As vitrification becomes an increasingly used method, I hope to see egg freezing become a realistic choice for women who are not ready to start a family. As a fertility doctor, all too often I see women looking to preserve their fertility too late as a result of lack of awareness. Egg freezing is a good option for those looking to safeguard their fertility in the hope of becoming a biological mother later on. Timing is everything if you are considering freezing your eggs – the younger your eggs are, the higher the chance of success.
If you’re thinking about freezing your eggs it is important to be aware of your fertility health. Having an expert fertility scan and taking a blood test that detects levels of Anti Mullerian Hormone (AMH) will provide you with a good indication of your egg reserve and overall fertility, so is certainly worth doing. Knowing how many eggs you have gives you a good idea of how many you will be able to freeze and will help to inform your decision. When it comes to the number of eggs you should freeze, again this very much depends on your age and should be discussed with a fertility specialist. If you are under 36 and have a normal egg reserve, typically around 10-12 eggs could be frozen in one cycle. If you are older, it is likely you will have fewer eggs to freeze, simply as a result of a naturally depleted reserve.
Modern freezing treatments are successful and have given a real choice to women looking to preserve their fertility. Whether it be a couple going through IVF treatment, a cancer patient wanting to safeguard the possibility of having a child after treatment, or a woman who simply isn’t ready yet, vitrification provides an important and valid choice for women and couples.