Of course, the sex of a baby is assigned at birth based on visible primary sex characteristics, like genitalia. While for most people, their assigned gender identity lines up with their anatomy, this isn’t always the case .Fetal genitalia can also develop in atypical ways, leading to intersex characteristics that don’t fit our conventional ideas of gender. So while gender reveal parties can be a lot of fun for expecting families, it’s important to remember that gender identity is fluid and only the person themselves can determine who they are.