I found a study that was done on egg freezing in fertile women: Thomas J. Kim et al., “Vitrification of oocytes produces high pregnancy rates when carried out in fertile women” from Fertility and Sterility, January 2010.
I did not read the entire paper because only the abstract is free, and buying the full paper costs over $30. But I can see from the abstract that the live birth rate per vitrified and warmed egg was 5.1% in this study. That is actually pretty good in the egg freezing world. Let's say I get 12 eggs to freeze out of my next egg freezing cycle--if this study is right, that could mean an over 60% chance of having a live birth!
What is unique about this study is that it was done on fertile women who were using their own frozen eggs. Most egg freezing studies are either done on egg donors or on women who are already struggling with infertility. So, it is hard to know how applicable the results of most studies are to someone like me who is going through elective egg freezing:
- Studies done on egg donors: these women are probably more fertile than most women going through elective egg freezing, because they tend to be younger. Different egg donation programs have different age cutoffs--a quick internet search revealed cutoffs of 28, 29, 30, 32, 34, and 35 in various programs. But in any case most egg donors are on the young side and therefore success rates with frozen donor eggs might be higher than success rates for most women going through elective egg freezing.
- Studies done on women already struggling with infertility: these success rates may be lower than success rates for women going through elective egg freezing, because the women are already having trouble conceiving. That could mean that their egg quality or egg quantity is lower than for the average woman going through elective egg freezing.
In case you are wondering why women who are already going through infertility would be freezing their eggs--the most common reason is that they are going through normal IVF but that for legal or ethical reasons, they cannot or don’t want to make many embryos. For example, there was legislation in Italy that meant that only 3 embryos could be created. So in Italy, women would go through the egg retrieval, have the 3 embryos made, and have the rest of the eggs frozen. It is unfortunate that women/couples in Italy had to deal with this restrictive legislation, but we also learned a lot about egg freezing because of it--a lot of the studies on egg freezing come from Italy.
Incidentally there is an egg freezing calculator here:
You type in how many frozen eggs you have, what age you were when they were frozen, and indicate if they were frozen using the slow freeze or vitrification method and it spits out the chance of having a live birth from those eggs. (Note: I find that the calculator is a little buggy and sometimes it doesn’t work.) As I mentioned in a previous post, I already have 11 frozen eggs that were frozen with the slow freezing method when I was 32. According to this calculator, that gives me only a 10.9% chance of having a live birth. Gulp! That’s not a very high chance! I’m glad that I’m moving forward with another cycle, with a clinic that uses vitrification, to increase my chances.
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