For what its worth we wanted to know with DS but we had a number of scans that said he was a boy and then a girl and so on.

I finally worked out a reply that made people laugh and move on: "Well we're fairly certain its human and probably ours, but a puppy would be great also"

This time around we found out and wanted to tell as it is clearly a girl but now everyone is all "well we will wait till its born just in case" - which is kinda upsetting too in its own way.