In the field of medicine, it is very difficult for doctors, nurses, and other medical providers to address the needs of the patient without knowing the patients' true gender identity. Its come this far and the future of medicine is really on its edge at the moment thanks to other growing issues in the medical community from questionability, lack of credibility, greed, medical malpractice, and private practices being scooped up by bigger organizations.
This isn't the 70's, 80's, 90's, and 2000's anymore.