Nobody is “assigned” gender at birth.
The doctor looks and states the obvious.
Amen to that, FRiend!
Read any literature published prior to 1970 and you will probably never be able to find the term gender used to refer to people. That is because everyone was taught in grade school then that gender only applies to pronouns, not people and there are three genders, masculine, feminine and neuter. The word began being applied to people along about the time that Linda Ronstadt recorded, “Poor, Poor, Pitiful Me.” In that song she referred to a certain man as being, “a credit to his gender.” I was taught before puberty that referring to anyone as being of male or female gender would get me a big red F in English.