It’s a really simple question – what is the average number of blastocysts per IVF cycle? After our failed IVF cycle I posted a status update in my local resolve support group’s facebook page, I explained what had happened with our cycle: 14 eggs retrieved, 11 mature, 11 fertilised, 2x 5 Day blastocysts transferred (5BB & 5CC) on Day 5, 9 still alive on day 5, but 0 were of sufficient quality for cryopreservation. Some ladies commented how they had similar results with 0 embryos making it to the freezer, and one lady posed the very good question how common is it to have 0 make it to the freezer? Perhaps it is more common than we think? So it got me thinking…at no point has my doctor said what a typical number of eggs, embryos or blastocysts she would expect out of a cycle for us – the only stats we were ever told was all about our likelihood of a successful pregnancy from 1 cycle of IVF, and ultimately, a live birth. And of course, that is the only statistic we only really care about, right? This holds true, until you get a Big Fat Negative (BFN), then the other statistics start to matter and grind at you.
So I looked into it, and asked google – what is the average number of blastocysts per IVF cycle? But I couldn’t find an easy answer, or at least one that I held great confidence in. I’m the kind of person who needs to see the supporting evidence, and not just some seemingly arbitrary numbers some random person has posted on a website. But although I didn’t find any national statistics per se, what I did find, made me feel a whole lot better about our last cycle.
The statistics that the Pacific Fertility Center in Canada are claiming are :
11 – Average number of eggs retrieved
9 – Average number of mature eggs
7 – Average number of eggs that fertilise (approximately 80%)
7 – Average number of fertilised eggs that will form embryos (98%)
7 – Average number of embryos on Day 3 of culture
3.5 – Average number of blastocycts on Day 5/6 (50% of good quality day 3 embryos make it to blastocyst)
It was not clear if this was their clinic’s statistics or where the source of this data came from. So my confidence is not high in it, I don’t know over how many cycles or patients this average is calculated. But at least it gives you a flavour of what numbers to expect. Note, it does not mention average number of blastocysts making it to cryopreservation!
Another clinic, Advanced Fertility Center of Chicago, provides a nice pretty chart of their own statistics, broken down by age for the period of 2003-2005. First of all my first alarm bell is that is over 10 years old now! Has anything changed in Assisted Reproductive Technologies in the last 10 years? Hmmmmm. Anyway, here it is….Their numbers are slightly lower than the Canadian clinic’s…but there could be many reasons for this because, again, there is no clue as to how many cycles/patients this average is calculated over. This clinic does publish their statistic of how many blastocysts make it to cryopreservation. And here is the money shot statistic people!!!! Just look at how low these numbers are! An average of 1.7 for women younger than 35 years old. And this statistic is a little bit more up to date than the ones above – this was for cycles from 2010-2011.
So what is the point of this post? The point is that we didn’t have any blastocysts that made it to cryopreservation, but we did have 2 blasts that were transferred and 1 that could have been frozen, but they decided it might not survive the thaw. For our first cycle we had one blast make it to the freezer. The point is, we had high expectations for more to make it to the freezer, when in actual fact the reality is, we were better than average to have so many good Day 3 embryos and we were typically average with transferring 2 on Day 5. Yes, IVF cycle 2 was a failure, but we were pretty average with our second cycle!!! This doesn’t mean we are less likely to succeed with cycle 3, rather the odds ARE in our favour.
Happy dance Dani!!!
 Source: http://www.advancedfertility.com/ivf.htm
 Source: http://www.advancedfertility.com/cryo.htm