In most cases if they are having regular ultrasounds a incorrect identification will be picked up and advised before the birth. I've not herd of anyone who got to the birth and got a different gender to one they were advised by certified doctors.
At 16 weeks i was told boy then at 20 weeks it was a girl!!
They told my friend she was having a boy even had 3 ultrasounds. When the baby was born it was a girl. The cord was in between her legs so they thought it was boy parts.
Bt if youre referring to was told boy and gave birth to a gurl this happened to my aunt..she was told girl twice and wen she gave birth it was a boy.
I've heard of this happening that's why I went to a 4d boutique and got my gender scan andall the boy parts where there then my doc double checked and said defidefinitely a boy
When my friend was pregnant she was told girl throughout her whole pregnancy and baby was,a boy