The surrogate may have a clause in her contract that needs to be considered too.

As long as she's ready for multiples. We put in 2, and have twins.

Are they three day or five day embryos? Also, I don't know much about FET, but I think it's likely that all three won't make it through the thaw.

I have a family member who will using a surrogate. She and her husband have 3 frozen embryos from about 10 years ago. This is a one shot deal - they can only afford 1 cycle. I know nothing about IVF, but seems to me they should try transferring all 3, correct? I know the risk is multiples, but what other downsides could there be?