Patrick Semansky/AP
Missouri Attorney General Andrew Bailey speaks with reporters outside the US Supreme Court in Washington on February 28.
CNN  — 

Advocacy groups sued the Missouri Attorney General Monday after he announced an “emergency rule” limiting transgender care for minors and adults – a rule that is expected to go into effect this week, his office announced this month.

Gender-affirming care is medically necessary, evidence-based care that uses a multidisciplinary approach to help a person transition from their assigned gender – the one the person was designated at birth – to their affirmed gender, the gender by which one wants to be known.

The new rule claims people often take “life-altering interventions,” like pubertal suppression or gender transition surgery, “without any talk therapy at all,” and that the emergency action is “needed because of a compelling governmental interest and a need to protect the public health, safety, and welfare” of Missourians.

Among other stipulations, the rule says it’s “unlawful” for individuals or health care providers to provide gender-affirming care without confirming that a patient has “for at least the 3 most recent consecutive years … exhibited a medically documented, long-lasting, persistent and intense pattern of gender dysphoria.”

The rule is expected to go into effect Thursday and will expire February 6, 2024, a release from Attorney General Andrew Bailey’s office reads.

Petitioners sued to stop the rule, asking the Circuit Court of Saint Louis County to declare it invalid “due to the Attorney General’s lack of statutory authority to promulgate it” in addition to other legal arguments, according to the petition filed by advocacy groups representing Southampton Community Healthcare in St. Louis and several providers and patients.

“The Rule targets gender-affirming care with unprecedented and unique restrictions so onerous that it effectively prohibits the provision of this necessary, safe, and effective care for many, if not most, transgender people in Missouri,” the petition says.

The suit also seeks a stay on the rule’s expected Thursday start date and requests that the court award reasonable fees and expenses as well as any relief the court deems just and proper, the petition says.

“Our regulation enacts basic safeguards for interventions that an international medical consensus has determined to be experimental,” Bailey said in a statement to CNN. “Rather than ensure that patients are protected by common sense safeguards, these organizations are racing to court in an effort to continue their ideologically-based procedures masquerading as medicine.”

The attorney general’s office said earlier Monday that the regulation “is based on dozens of scientific studies and reports, which are cited in endnotes.”

Civil rights organization Lambda Legal fired back at Bailey’s statement.

“This emergency rule is an unprecedented attempt to prevent broad categories of transgender people – including adults – from being able to obtain gender-affirming care, which is evidence-based, supported by the overwhelming medical consensus of major medical organizations, and in no way ‘experimental’,” a statement from Lambda Legal attorney Nora Huppert said. “And any ‘race’ to obtain relief against this rule is purely a result of the Attorney General’s decision to implement sweeping, draconian regulations that threaten trans people’s access to medically necessary care, even decades into their transition, on two weeks’ notice.”

An organization that focuses on issues in transgender health, the World Professional Association for Transgender Health, and one of its affiliates, the United States Professional Association for Transgender Health, have said the rule is based in part on “flawed reports.”

“The emergency regulation issued by Missouri Attorney General Andrew Bailey is based upon manipulated statistics, flawed reports, and incomplete data, and prevents the provision of medically necessary care,” the associations said last month, reacting to an earlier announcement from Bailey’s office about the forthcoming regulation.

The petition filed Monday says transgender patients at Southampton Community Healthcare – one of the plaintiffs – “have expressed to its providers that they fear they will be denied continuation of their hormone therapy if they share symptoms of other mental health issues.”

“Missouri Attorney General Andrew Bailey’s emergency order is a baseless and discriminatory attempt to limit the healthcare options for transgender individuals, who already face several barriers accessing necessary and life-saving medical care,” Southampton Community Healthcare’s Dr. Samuel Tochtrop said in a statement. “It’s our privilege as Southampton Community Healthcare to fight this rule on behalf of transgender Missourians.”

The president and CEO of the LGBTQ advocacy group GLAAD called the measure “an unprecedented attempt to restrict an entire group of people.”

“The rule issued by Missouri’s attorney general includes outright lies and falsehoods about best practice care supported by every major medical association,” Sarah Kate Ellis said in a news release. “This is an unprecedented attempt to restrict an entire group of people from being able to make informed medical decisions in order to live and thrive.”

“Health care decisions need to remain between patients, their doctors, and their loved ones – not subject to the whim of craven politicians looking to score political points,” Ellis said. “GLAAD is sending all of our support to our organizational partners and activists in Missouri, who are working hard to undo this unconstitutional directive as soon as possible. Transgender people belong, and this rule will not stand.”

The action in Missouri comes after North Dakota Gov. Doug Burgum signed a bill this week banning gender-affirming care for most minors with the possibility of a felony for health care professionals who provide it. Indiana and Idaho enacted their own bans on gender-affirming care for youths this month, and several other states have signed into law restrictions on gender-affirming care for minors in the past few years.

CNN’s David Close and Lucy Kafanov contributed to this report.