Can you tell the gender at your 12 week scan?

Ashley

My friend had her 12 week scan the other day and she had her little boy with her and the dr doing the ultra sound said to her little boy “come over here and have a look at your brother” pointing to the screen! My friend is sooo annoyed as she thinks the dr has told her what she is having and she dosnt want to know. Is it possible the dr knew shes carrying a boy??