Organisations representing more than 30,000 health care and legal professionals have signed a letter affirming biological sex is the best indicator for making public policy.

The letter begins with, “We, the undersigned medical, legal, and policy organizations and individuals applaud the Trump Administration's intention to uphold the scientific definition of sex in federal law and policy, such that girls and women will regain their sex-based legal protections, and the human rights of all will be preserved.”

The lengthy document addresses 9 ways expanding the scientific definition of sex harms people and is unscientific. They address the consequences for delivering professional health care to their patients

“The discussion around transgender policy so far has been largely based on emotion and feelings,” said Kirralie Smith, spokeswoman for Binary. “This new document representing a large number of healthcare and legal professionals is very encouraging. It appeals to science and facts while upholding the dignity of all people. This is the pathway that can ensure good outcomes for everyone.”