Unassigned At Birth (UAB or UAAB), also seen as GUAB/SUAB (Gender/Sex Undesignated At Birth) or UGAB/USAB (Unassigned Gender/Sex At Birth) refers to someone who does not have an assigned gender at birth.[1] It is most commonly designated with the letter "U". It is most commonly used by parents who are raising their children without a prescribed gender.