((Hugs)) -- I guess it is bittersweet to get the answer, because it is tough to know that this little embryo with all your hopes riding on it didn't have a chance, yet also you know that there is nothing you could have done to cause the m/c.
Twoboysandcounting:The paperwork said that this accounts for 99% of spontaneous abortions, which seems extremely high
I would interpret this as meaning: most very early m/c are caused by chromosomal abnormalities; not that they are all caused by this particular abnormality.
Twoboysandcounting:I'm not sure how many probes we would have had to have done to find this particular issue anyway.
It depends on which chromosome it was. There are supposed to be 46 chromosomes, in 23 pairs, and in this case there was one missing. In PGD, the most commonly tested are 13, 15, 16, 18, 21, 22, X, and Y, becasue those are the ones that most often have abnormalities. So it is possible you would have found it by testing those, but if it was one of the others it could have still passed PGD. As a PP said, you would have to do CGH to check them all.
Twoboysandcounting:I also wonder if taking out the cell for PGD could contribute to this
Given that nearly ALL very early m/c's are attributed to chromosomal abnormalities, I don't think you have to look to PGD as the cause. The only way to find out would be if the PGD lab still has the original cell, and if that particular chromosome could be checked. (It would be a good question to ask.)
Twoboysandcounting: I'm hoping this doesn't mean our 5 frozen girls have a greater chance of being abnormal too.
I do NOT think this spells doom for your other embies! They may all be perfect! Lots of pink dust to you. 