With the thaw coming up on Friday, I'm getting a bit more anxious. And doing exactly what I should not be doing by googling any new academic information (or otherwise) on the success rates of frozen donor eggs. I know we've already bought the lottery ticket. Nonetheless, I'm still calculating the odds of winning.
There was a recent article in Science on improvements the success rates from frozen eggs. As Science is not too shabby of a journal, I got the article. The main gist of this article is that eggs have been frozen since about 1986, but until the advent of ICSI , it was simply not viable. The egg's membrane gets a little tough after being frozen so it's harder for the sperm to enter. ICSI changed all that so the REs became more interested in using donor eggs.
There's also a new technique for freezing eggs called vitrification versus the old way of doing it, called slow freeze (or the roll-off-your-tongue formal name gamete cryopresevation). From what I can gather, virtification is a quick-freeze, dip in some liquid or another whereas slow-freeze takes up to 1.5 hours of slowly freezing the eggs. And the gist of the debate is that vitrification yeilds more usable eggs at thaw than slow freeze. Like, a lot better in both quantity and quality. In fact, some REs say that vitrification yeilds about the same result as fresh eggs. However, there have only been 100 births ever from vitritifed eggs and about 300-500 births per year world-wide for slow-freeze eggs. With those sorts of numbers it's hard to argue that one is really better than the other. (100 total is a really small sample size) Nonetheless, the 95% survival rate for vitrified eggs is impressive as the Science article above says.
Guess which one our clinic used?
How about "Not Virtification." In fact the clinic got all cranky when I asked which one they used saying that the research was not yet conclusive. Considering that yes, doctor's are likely to exaggerate their success rates and also that this clinic has a Really High donor egg success rate, I'm not going to get completely freaked out, just a little.
However, the Science article says that one needs about 50 slow-freeze eggs for a viable pregnancy whereas one only needs 21-25 eggs for a successful vitrified pregnancy.
That's when I start freaking out. We have 15 slow freeze eggs. ((gulp)) I start twittering and I don't mean updating my friends.
But then I go back to this peer reviewed article in Fertility and Sterility reporting a pretty signficant success rate (about 30%) for frozen DONOR eggs. That's a whole different ballgame than regular frozen eggs. Most women freeze their eggs in their 30s not their 20s. Their success rate is already lower. And I know that our donor was a true fertile Myrtle (as opposed to me, being somewhat of a fertile turtle). So then I reassure myself because I honestly believe that if 75% of these eggs can make it through the thaw stage, we'll have a decent chance.
And last night as I was getting all dramatic on myself thinking "If we don't get pregnant, this will be the worst thing ever" I had to stop and say "Ummmm, no it won't. It won't even be close." I've had a lot worse things happen than not getting pregnant on an IVF cycle. I will undoubtedly be sad. But it will not be the Worst Thing Ever.
I still don't know if I would be ready to give up if it doesn't work. (DE Daddy and I are in the midst of debating about this.) I'm still getting anxious. But this certainly will not be the Worst Thing to Ever happen to me.