Of course, I don't know how these guys will do but I'm feeling pretty good they will be fine.
I've lost sleep and struggled quite a bit on transferring one vs. two. It's a very hard call either way. The truth is I would kick myself in the ass if I transferred one and it failed (another trip out here plus cycle is 6K - which is nothing to sneeze at) and I would kick myself in the ass if I wound up with twins. So, the ONLY way not to kick my ass is to have one implant. (you listening embies? just one should plan to stay, any other should decide my uterus is just a mess and refuse to have any part of it!)
But seriously, the success rate for a completely anonymous (i.e., not a sister or designated donor who may not be the most optimal donor but is chosen by patient all the same) proven in-house donor is around 85%, per Surrey, Sc.hoo.lcraft, nurses. THAT is the success rate I came here for - otherwise, I could have stayed in NJ, spent about 10K less and accepted lower odds.
So, with that in mind, how could I really only transfer one? Besides which, the former couples with this donor wound up with singletons and if the donor was 23 instead of 31, I would worry more about the twin thing. But at 31 she's still young but not so young that you wouldn't expect some chromosomally less-than-stellar embryos in that bunch.
And then there's this. Let's say I transferred one and it failed. After I reconcile having to come back for a FET, I wind up in EXACTLY the same place I am now - wondering, do I put back one or two.
Yeah, unless Surrey and the embryologist basically hold up a hatching blast and declare it's the most perfect specimen they've ever seen - that this has a 90% chance of success on its own, that this blast will be photographed for Embryology textbooks to illustrate what a blast should strive to be - I'm transferring two.
Good night my friends!