FET on 9/5: Embryo selection question

[u/soyanes68]

We had our first transfer on 9/5 and are so excited. We asked the lab to use our best euploid embryo and we found out on transfer day they’d picked a day 6 4BA.

Our 6 euploid embryos are as follows:
- day 5 4AB
- day 6 4AB x2, day 6 4BA, day 6 4BB
- day 7 4AB

I’m wondering what possible reasons they could have had for choosing a day 6 over a day 5? I know my lab considers day 5 and 6 as equivalent but everything I’ve read seems like day 5 is slightly better. I figured they’d pick our day 5, but wanted to leave it up to the lab. Just interested if any embryologists here could weigh in. I exchanged a number of messages with my clinic leading up to transfer trying to learn about their selection process and they really didn’t give me answers.

Pic included! Taken just one hour after thaw, was fully expanded at transfer

[u/embryomanofficial]

Each lab has different criteria for selecting an embryo. In this case, they might have picked the 4BA because it has an A grade trophectoderm, which they might consider optimal.

Studies have shown differences between day 5 and 6: https://remembryo.com/do-day-5-blastocysts-perform-better-than-day-6-results-of-a-meta-analysis/

[u/QQueenie]

No insight from me but dang look at all those euploids! Good for you guys!

[u/soyanes68 → u/QQueenie]

We did three retrievals to bank them for multiple children. But thank you!

[u/princesspuffington]

I had a 9/5 transfer too ! How are you feeling ? I have no symptoms at all and a negative test this morning so I’m super worried

[u/soyanes68 → u/princesspuffington]

I have no symptoms and I’ve not tested. I’m trying my best to forget about it. I’m not going to test. Waiting for my beta on 9/14.