15th August 2014 | by MFC Team
I’m 34, single and seriously considering freezing my eggs. But recently I read an article that cited the results of a 2013 study published in Fertility and Sterility reporting a 77% failure rate for women aged 30, and a 91% failure rate for women aged 40 using frozen eggs. Based on these stats, do you think it’s worth it for me to freeze my eggs?
Written by our medical expert Dr. Stephen Hudson, Director of the Victoria Fertility Centre in British Columbia, Canada.
This is a very important question and I think one on the minds of many women. As an introduction to answering this question, I will first explain the history behind egg freezing.
Traditionally, the technology used for freezing embryos and sperm has been “slow freezing”. One of the major difficulties with freezing human tissue is ice crystal formation during both the freeze and thaw. “Slow freezing” was effective for sperm and embryos, but not as effective for eggs. Eggs are the largest and most sophisticated cells in the human body – and because the cell is so big, it has more water. More water means more problems with ice crystals during freezing and thawing.
Then came the newer technology called “Vitrification”. The word “vitreous” literally means “like glass”. During this process eggs are “flash frozen”. This means there is no time for crystals to form. This has proven VERY effective for egg freezing, and now means that women can effectively freeze their eggs and preserve their fertility.
It is also important to understand that not every egg is perfect. There are only a percentage of eggs that actually have the ability to fertilize and develop into an embryo that has the potential to produce a baby. Also, not every perfect embryo will implant in the uterus. The older a woman is, the lower the percentage of eggs that are perfect. This is why it often takes older women more time to conceive, and why miscarriage rates are higher.
Until recently, egg freezing for fertility preservation has focused on young women diagnosed with cancer, and requiring chemotherapy, which can damage their ovaries. However, over the more recent years, many healthy women anxious about advancing age have looked at egg freezing for fertility preservation.
The article cited in your question has looked at both slow freezing and vitrification. Vitrification is superior, and most clinics are now using this technology. But just because it can be done, does not mean that it is a good idea for everyone. There are of course benefits to egg freezing, however there are also risks.
The potential benefits are obvious – you will have eggs frozen at your current age. The treatment risks include: a very low risk of ovarian hyperstimulation syndrome from the fertility drugs (this condition has virtually been eliminated by newer protocols), the surgical risks related to retrieving the eggs, and the risk of ovarian torsion (extreme rotation of the ovary). All these complications are very uncommon. When we freeze eggs we have to do ICSI (intra cytoplasmic sperm injection) to fertilize them. This technology slightly increases the risk of birth defects – though once again this risk is small.
Dr. Kutluk Otkay’s team in New York has analyzed data from 10 published studies which includes 2,265 cycles, and from his calculations has provided the means to predict the odds for a live birth based on a woman’s age and the number of eggs frozen.
He has created an “egg freeze calculator” providing the probability of a live birth related to age, which can be accessed through www.i-fertility.net. (I have summarized some of his data below so that you can have some idea of expectations.)
The bottom line is if you are concerned about your fertility for whatever reason, speak with a doctor at a Fertility Centre who can help you to determine if freezing your eggs would help you increase your likelihood of conceiving a child in the future.
Chances of having a live baby using frozen eggs as per maternal age at the time of egg freezing and number of eggs frozen (using vitrification as the method of freezing).
|Age at time of freezing eggs||Number of eggs frozen||Chance of having a live baby|
|25 years||10||35 %|
|30 years||10||27 %|
|32 years||10||24 %|
|34 years||10||22 %|
|36 years||10||19 %|
|38 years||10||17 %|
|40 years||10||15 %|
|42 years||10||13 %|
(Table compiled by Dr. Hudson from Dr. Otkay’s Egg Freezing Calculator. You can access it here. Please note that these are estimates provided for general information purposes).