The News

A state judge in Missouri on Friday denied a request to temporarily block a state law passed this year that restricts gender-related medical treatments for minors. The ruling was issued by Missouri Circuit Court Judge Steven Ohmer, three days before the ban is set to go into effect. A legal challenge to the ban brought by civil rights groups is ongoing.

Why It Matters: Adolescents and adults are likely to have difficulty accessing gender-related health care.

Under Missouri’s law, clinicians will not be allowed to treat any minor who is not already receiving gender transition care, which includes drugs that suppress puberty; hormone treatments with estrogen or testosterone; and, in rare cases, surgeries. Minors currently receiving care can continue to do so.

The law will also affect transgender adults, as it bans Medicaid coverage of gender transition care for people of all ages in the state. The law has a “sunset” provision and will be in effect for four years.

The legal challenge to Missouri’s ban has been particularly high-profile. A whistle-blower from a pediatric gender clinic in the state, Jamie Reed, said earlier this year that doctors at the clinic had hastily prescribed hormones with lasting effects to adolescents with psychiatric problems. Ms. Reed filed an affidavit about her experience in February and testified on Tuesday in favor of the ban.

Chloe Cole, a 19-year-old who has frequently testified to state legislatures about regretting gender treatments she received as a younger teenager in California, also testified on behalf of the state of Missouri against the injunction.

The plaintiffs in the legal challenge include three transgender minors who are seeking medical care to transition and will no longer be able to do so once the law is in effect. The plaintiffs also include doctors in the state and two national L.G.B.T.Q. advocacy organizations. Doctors who violate the new law could lose their medical licenses or be sued.

According to the Williams Institute, a research center at the U.C.L.A. School of Law, an estimated 2,900 minors in Missouri identify as transgender.

Background: Legal challenges have seen mixed results recently.

At least 20 states have banned or severely restricted transition care for transgender minors in a flurry of legislation, led by Republicans. Most of the bans were passed during this year’s legislative session.

Legal challenges have been brought by civil rights groups in at least 13 states. In June, a judge struck down a ban in Arkansas — the first such law to be passed in the United States — arguing that the law unfairly singled out transition care and transgender children. The ruling was a significant victory for transgender minors and their families. On Friday, a state district court judge in Texas temporarily blocked a law that would ban gender-related treatments for minors.

But a series of legal setbacks has clouded the picture. In August, a federal appellate panel ruled that a similar ban in Alabama could be enforced while the case proceeds. Other disagreements in the courts have signaled that these cases may ultimately be decided by the United States Supreme Court.

The American Academy of Pediatrics last month reaffirmed its position that these types of medical treatments are beneficial for many youth, and has vehemently opposed any government interference in medical decisions that it says are best made by parents and doctors. But the group also took the unusual step of commissioning a review of medical research on the treatments.

What’s Next: The legal challenge continues as the law goes into effect.

The law will restrict any new patients from receiving gender affirming treatments while the case is heard in state court over the next year. And it will continue to prevent Medicaid coverage for the estimated 12,400 transgender people in the state.

Judge Ohmer, who typically presides over juvenile cases, wrote that the science in support of gender-related medicine for youth was “conflicting and unclear,” adding that “the evidence raises more questions than answers.”

In response to the ruling, the American Civil Liberties Union of Missouri said it would continue to fight to overturn the ban: “The case is not over and will go to a full trial on the merits.”