CLAYTON, Mo. — A Missouri judge on Wednesday temporarily blocked a first-of-its-kind rule restricting access to gender-affirming health care for transgender kids and adults, just hours before it was set to take effect.

St. Louis County Circuit Judge Ellen Ribaudo ruled against Republican Attorney General Andrew Bailey’s emergency rule on transgender health care, putting it on hold until at least Monday. Bailey has touted the rule as a way to shield minors from what he describes as experimental medical treatments.

Republican Missouri Attorney General Andrew Bailey speaks to reporters after taking the oath of office in Jefferson City, Mo., on Jan. 3. David A. Lieb/Associated Press, file

Transgender Missourians and health care providers sued to stop it from taking effect as scheduled Thursday. They argued that Bailey sidestepped the GOP-led Legislature and acted beyond his authority in attempting to regulate gender-affirming health care under the state’s consumer-protection laws.

The rule would “essentially outlaw, on less than two weeks’ notice, virtually all medically-necessary treatment for gender dysphoria in Missouri, treatment that is supported by every major medical association in the United States,” attorneys for the plaintiffs wrote in court filings.

The rule would have required people to have experienced an “intense pattern” of documented gender dysphoria for three years and to have received at least 15 hourly sessions with a therapist over at least 18 months before receiving puberty blockers, hormones, surgery or other treatment.

Patients also would first have to be screened for autism and “social media addiction,” and any psychiatric symptoms from mental health issues would have to be treated and resolved.

The rule allowed for some individuals to maintain their prescriptions while they promptly received required assessments.

Assistant Attorney General Joshua Divine argued that Bailey’s order does not ban gender-affirming care.

Divine said the rule provides “basic procedural guardrails.” He cited studies showing that a high percentage of kids seeking to transition are dealing with mental health issues. He said that rather than transition they should undergo “talk therapy.”

Bailey issued the restrictions following an investigation he launched in February into the Washington University Transgender Center at St. Louis Children’s Hospital. The investigation was prompted by a former employee who alleged the center was providing children with gender-affirming care without informed consent, not enough individualized case review and wraparound mental health services. An internal review by the university found no misconduct and determined that the former employee’s claims were unsubstantiated.