Oh - my clinic said the day 6 slightly lower implantation potential bc they were slow growing. I have a day 6 4BB that only thawed 80 percent but sounds like that's not far off from what you had

This is the previous poster, all mine are day6. My 2.5 year of is also a day 6. Once it's PGs Normal thebgrading is out the window, my doctor said.

Ok well mine isn't even a 4 or have a B or A. Mine are all 3BC or 3CB. One has 95 percent cell survival, two have 90. Then I have a 4BB day 6 blast that only had 80 percent cell survival and my lab said that would be a last choice bc 80 percent cell survival and Day 6 has lower implantation.