Zeam Porter played basketball on the girls team and it always felt like the wrong team, Porter said during the Minnesota State High School League’s public hearing on its proposed transgender policy Wednesday. Porter identifies as transgender and gender non-conforming instead of he or she. (Renee Jones Schneider/AP)

It had been a relatively quiet policy debate until the full-page ad appeared in the local newspaper. “A male wants to shower beside your 14-year-old daughter,” it said. “Are you OK with that?”

The ad, placed by a socially conservative group in Minnesota, was meant to snap attention to a proposal to allow transgender students to play on teams based on their preferred gender rather than the sex assigned to them at birth.

It appears to have worked. More than 100 community members flooded a meeting this week near Minneapolis, and thousands more sent e-mails. In response, the quasi-public body governing high school sports in Minnesota decided to delay a vote on a new policy covering sports participation by transgender students. Members of the board of directors said they needed more time to study the issue.

The policy, which they now plan to vote on in December, was an attempt to grapple with a question that has bedeviled many states: How do you deal with the growing number of children identifying as transgender who want to participate in the highly gender-specific worlds of high school sports and extracurricular activities?

School systems have scrambled to adopt policies to deal with these students while also being sensitive to concerns over locker-room privacy and any advantages a more physically imposing transgender female might have on the field against other girls.

“Generally, our society is becoming more accepting in its understanding of gender identity and what that means, and we’ve been very lucky that in the last few years this cadre of young kids has started identifying themselves as trans from a young age,” said Helen Carroll, sports project director at the National Center for Lesbian Rights, who helped write a model policy for school systems. “It’s really pushing folks to really grapple with and understand what it means.”

But activists like Carroll have run into opposition, including from groups that say gender is a biological fact rather than a social choice and that schools should not cater to a small subset of the student body.

The number of students asking for such accommodations nationally is indeed very low, Carroll said, estimating that, nationally, fewer than 10 students a year make such requests. Advocates and students say that is because transgender students are typically afraid of bullying or very self-conscious about their bodies and therefore choose not to participate in sports.

“I just didn’t feel like I was accepted anywhere in athletics,” said Jae Bates, 18, a student at the University of Puget Sound in Washington who graduated from a Minnesota high school. Bates had been active in soccer, swimming and track but dropped the first two after coming out as male just prior to his junior year. He remained on the girls’ track team, in part because the coach was an adviser to his school’s gay-straight alliance.

Thirty-two states have adopted policies in recent years regarding transgender athletes, according to the National Federation of State High School Associations, with several states placing restrictions on their ability to compete with teammates of their preferred gender. For example, Virginia, Georgia and North Carolina require students to play on teams based on the gender listed on their birth certificate, according to Trans*Athlete, an online clearinghouse for information about transgender athletes.

At least 10 states and the District allow transgender athletes to play on their preferred teams, according to Trans*Athlete. New York is expected to consider such a policy this month. The one considered this week by the Minnesota State High School Sports League would have left discretion up to individual schools, with the caveat that students and their parents could appeal the school’s decision to the league.

The decision to delay the vote pleased opponents of the policy. Both sides said they plan to muster support for their views before the vote in December.

Autumn Leva, director of policy and communication for the Minnesota Family Council, said her group will be “more than happy to bring in another viewpoint” as discussions continue. She said one problem is the policy is silent about how religiously affiliated private schools that are part of the state league will have to accommodate transgender students if they are visiting from other schools.

“What if the Christian schools can’t accommodate, or do not allow their girls to compete with a team that has a boy on it for safety reasons?” she said. “Does the private school have to forfeit?”

The ad in the Minneapolis Star-Tribune was placed by the Minnesota Child Protection League, which on its Web site opposed the policy in part because there are no “accommodations made for those who believe that gender is a biological and genetic reality, not a social choice.”

The group suggested that girls could be at risk of greater injury on the field if they are playing alongside “biological boys.” And it warned that the policy could mean a transgender girl, with intact male anatomy, could shower next to other girls or bunk with them on overnight trips, putting them at risk of sexual assault.

The accusations galled advocates for gay and transgender youth, who say transgender kids are much more likely to use private stalls to change or shower rather than risk someone seeing their bodies. They say transgender girls who have been permitted to play on girls’ teams have not outstripped their teammates in ability. And they say it is unfair to characterize these children, who are often more vulnerable than their classmates, as predators.

“It absolutely misrepresents the reality of what it means to be transgender,” said Alison Yocom, a Minneapolis mother of a transgender 11-year-old boy who is undergoing hormone therapy.

“You’re not a boy showering next to a girl,” she said. “A transgender girl is a girl. There’s a difference between your parts and your gender, and I know it’s hard to understand and there is a lot of controversy around this, but to be misgendered as a boy when you are actually a trans girl is incredibly offensive.”

Correction: An earlier version of this story used an incorrect pronoun in the caption for the person in the photograph, Zeam Porter. Porter's preferred pronouns are “they” and “them.”