If I remember correctly, you are doing biopsy on day 3 embryos and CGH, and then grow blast and freeze them at SIRM, right?
My clinic offered me to do the following:
1) thaw blast, biopsy and then CGH, freeze. Need to thaw again when doing transfer. My RE doesn't really like this approach because the blast needs to be thawed and frozen twice.
2) biopsy on d2, not d3, embryos, then let them grow to blast and freeze the normals. My RE is trying to push this approach.
However, I am a bit concerned if the biopsy on d2 4-cells will actually do more harm than good. So I have been doing quite a bit of reading over the last few days, and I found some research that stated that 5% of the normal embryos biopsied on day 3 couldn't make it to blast and arrested before then. Theoretically they should, but there is suspicion that the biopsy process may have hurt them at the early stage (or culture, or a combination of factors). I have also read quite a few cases of normal blasts not making it after CCS at CCRM.
So I'd like to know if SIRM believes that CGH on a day 3 embryo is considered safer than blast freezing and thawing and freezing and thawing?
Here is the way that I look at it:
I don't mind early miscarriages, it does little harm to the carrier. I do mind 20 week abortion because of the harm to the body of my GC, and all the cost involved. It seems like with biopsy on a pre-blast embryo, there is a 1/20 (5%) chance of loss for normal embryo. But the ratio of Down and other rarer disease is about 1/64. Since that risk is lower than the loss of embryo, shouldn't I opt for the lower risk 1/64 and push ahead with CVS (loss ratio of 1/300) instead of taking the 1/20 risk?
MIR, all I can say is that my RE was not worried about thaw, biopsy, freeze and eventually thaw again someday. Both my embies survived the thaw and biopsy process. I would be petrified of taking a cell from a day 2 embryo and that disruption, versus taking a few from a blast. With a blast they can grab cells from the area that will develop into the placenta rather than the baby. With vitrification I think the freeze part at least is pretty negligible. If the lab is skilled the thaw should be fine.
Does your RE have a comment on mosaicism? I have read that that is a concern with earlier embryo biopsies.