有。因為each embryo probability is individual. so it doesn't affect each other.so its mutually exclusive. 1 reason 放2個,第一age, 第2 quality 第3 cost of 放1 or 2 is the same. 第4 save time.
so if 2 embryo 1 implant and 1 don't, it would be same possibility if they are transfer in individually.
also twins put more risk to the mother.
I transfer 1 and failed last time. I am planning to transfer 2.