TOPEKA, Kan. — As children across the U.S. head back to classes and practices for fall sports, four more states are expecting their K-12 schools to keep transgender girls off their girls teams.

Kansas, North Dakota and Wyoming had new laws in place restricting transgender athletes before classes resumed, and a Missouri law takes effect at the end of this month, bringing the number of states with restrictions to 23.

North Carolina could enact a ban later this month, and Ohio could follow in the fall. A few laws, including ones in Arizona and West Virginia, are on hold because of federal lawsuits.

This year’s new restrictions are part of a larger wave of legislation across the U.S. against transgender rights. Republican legislators in some states have banned gender-affirming care for minors, restricted transgender people’s use of school and public restrooms, limited what public schools can teach about gender and sexuality and barred schools from requiring the use of a transgender student’s preferred pronouns.

The sports laws have been imposed since 2020, and most are aimed at transgender girls. A majority cover less formal intramural contests organized within a single school’s student body as well as contests among different schools, and some restrict transgender boys as well. Almost all say other students and their parents can sue schools that don’t enforce the restrictions.

Lawmakers expect a child’s earliest birth certificate to determine which sports teams they can join. Principals and coaches are expected to be the enforcers.

“Those are uncomfortable conversations,” said Jeanne Woodbury, interim executive director of the LGBGT+ rights group Equality Arizona. “Everyone is going through that process.”

She added: “For trans kids, it’s never been a walk in the park, but now they have this law to contend with on top of everything else.”

In Oklahoma, where a law has been in place since 2022, athletes or their parents must file an annual affidavit “acknowledging the biological sex of the student at birth.”

Kansas and other states expect school officials to review a child’s earliest birth certificate if questions arise about an athlete’s eligibility.

Bill Faflick, executive director of the Kansas State High School Activities Association, said his state’s law has been greeted by a “matter of fact” acceptance in rules seminars for administrators and coaches.

“It has not been met with any resistance and has not been met with any outpouring of support or opposition, one way or the other,” Faflick said.

Even before the laws against transgender girls on girls teams passed, some states largely blocked the practice by handling questions or concerns on a case-by-case level at the school or state athletic association level.

Supporters of the restrictions argue that they’re protecting fair competition and scholarship opportunities for young women that took decades to win. They say that well before puberty, boys have physical advantages over girls in speed, strength and lung capacity.

“It’s a puzzlement to me that more people aren’t feeling sympathy for the girls whose sports careers are ruined,” said Tom Horne, the elected Republican state school superintendent in Arizona, who is defending his state’s law in federal court.

Doctors, parents, and LGBTQ+ rights advocates counter that boys’ physical advantages come with a surge in testosterone during puberty — changes gender-affirming care blocks.

Critics also argue that transgender athletes are so few that schools and associations governing school sports can handle their individual cases without a state law.

Number of Trans Athletes Quite Small

For example, in Kansas, the State High School Activities Association recorded 11 transgender athletes during the 2022-23 school year, and three were trans girls. Before Florida’s law took effect in 2021, its High School Athletic Association had cleared 13 transgender students to play in the previous eight years.

Becky Pepper-Jackson appeared to be the only transgender girl seeking to play girls’ sports in West Virginia in 2021 when the then-11-year-old and her mother, Heather Jackson, sued the state over its law.

Because of their lawsuit, the West Virginia law is on hold, and Becky, now a 13-year-old entering eighth grade, threw the discus and the shot put in seven track meets this spring.

The state is trying to persuade a federal appeals court to let it enforce its law, and in a filing last month, it cited the longer distances Becky threw this year as a reason. The state said any time another girl finished behind Becky in either event — more than 180 times — the other athlete had been unfairly “displaced.”

Jackson said the state knows her daughter only “on paper,” and Becky improved by training relentlessly at home with her own equipment.

“As a parent, all we want for our children is for them to be successful and happy, period,” Jackson told The Associated Press. “That should be an opportunity for everybody, every time, everywhere in this country.”

Educators and LGBTQ+ rights advocates argue that transgender kids aren’t the only athletes likely to feel the effects of the laws. Some worry that parents will challenge the right to play of cisgendered girls who are taller or more muscular than their peers — or just a whole lot better.

One of athletes who sued Idaho over its 2020 law was a 17-year-old cisgendered girl, listed only as Jane Doe. The lawsuit said she had an “athletic build” and wanted to avoid ”invasive or uncomfortable” gender tests.

“It’s going to create this feeling in some people that, ‘I can go question someone’s gender, and it’s my right to do that,’” said G.A. Buie, executive director of United School Administrators of Kansas, an association representing public school leaders.

Parents, doctors and LGBTQ+ rights advocates say restrictions on transgender athletes are less about sports and more about trying to make transgender kids disappear from society.

“What lawmakers fail to understand is that transgender people, nonbinary people, intersex people, have always been here,” said Anne Lieberman, policy and programs director for Athlete Ally, a group that advocates for transgender athletes. “Unless it is known that a student is trans, it is very hard to keep somebody from playing sports.”