Quoting DifferentDay:" is that what everyone is basing this question on mostly, not fully, but mostly? That it was an EDD? Bc ... [snip!] ... of you who answered have lost a child then? Not being confrontational just asking if these things matter at all or not at all."
I say FULL focus on the child you have. And in the end, it IS an EDD. Anything could have happened to have the twins come earlier or later. I wouldn't acknowledge the day at all. And I wouldn't tiw it in with a birthday party
If you do anything, I would do it privately, when the child isn't around, not during the party.