Thanks for the info @hermia. I have been reading that some clinics offer testing on day 3 embryos. All of our embryos to date have arrested before day 5, so I'm really hoping that will be an option for us. Yes, the cost is pretty hideous! But I figure that at least it might give us some more clues as to what's going on and maybe avoid some wasted transfers that wouldn't have worked anyway. That's what I'm hoping anyway. Was the testing you did CGH? I'm just learning about all this stuff and getting my head around the different types of testing.