How do the embryologists know the day after ER what day they will do the ET?

I had my ER on Monday and they retrieved 16 egg and 8 fertilised through IVF, they rang me Tuesday morning to say I go back for a Day 5 transfer, but I'm nervous as to how they know they will make it to then, as don't want a cancelled ET!!!!

[DianeArnold Partner Nurse Fertility Network UK]

HiNikkiNak79. All getting very exciting no wonder you feel nervous! It seems as if the embryologist is going for a blastocyst transfer. In these cases, your embryos will be having extra care and watching to ensure you of a successful transfer, and maybe a couple of frozen ones too! Rest assured that the embryologists are very skilled at what they do, so stay near the phone and I wish you all the best. Diane

[Cialti]

They don't know for sure, but it's based on the number of eggs retrieved/fertilized. With 8 fertilized, you're likely to have enough embryos progressing to do a Day 5 transfer. Any embryos that don't make it that far almost certainly have some sort of abnormality that would prevent them from creating a healthy baby in you, so even though the numbers falling off can be scary, it's great to be able to focus on the very best embryos for transfer.

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Thank you both for the information and reassurance! All being well it's happening tomorrow at lunchtime! Fingers crossed x

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Hey well I had three Blastocysts and one of these was a grade 5 hatched this is the one that was placed back, the remaining 2 were being looked at this afternoon and then frozen. They are watching the remaining 5 as they are developing well but slower they said so will let me know next week what has happened. It was an emotional experience and we got to see it on a screen prior to transfer and it was very emotional. I have to say the nursing staff were very excited by this blastocyst, which made me feel better but don't want to get my hopes up x x

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Good luck x