By Lisa Rapaport

(Reuters Health) - Transgender adolescents may be less likely to be sexually assaulted when they can use school bathrooms and locker rooms that match their gender identity rather than their sex assigned at birth, a U.S. survey suggests.

The survey of 3,673 trans and nonbinary teens in American middle schools and high schools found that more than one in four reported being sexually assaulted in the previous 12 months.

When schools required students to use bathrooms and locker rooms based on their sex assigned at birth, transgender boys - who identify as male but are labeled female on their birth certificates - were 26 percent more likely to experience sexual assault.

And transgender girls - who identify as female but were assigned male at birth - had more than twice the assault risk when they had to use restrooms and locker rooms for boys.

"We can't tell from this study whether restrictive restroom and locker room policies cause sexual assault," said lead study author Gabriel Murchison of the Harvard T. H. Chan School of Public Health in Boston. "However, at the least, they seem to be a marker for an environment where trans and non-binary youth are at risk."

"This gives us a concrete place to start when it comes to making schools safer," Murchison said by email.

Most transgender students say schools have placed limits on their restroom or locker room use, the researchers note in Pediatrics. Often, they're required to use facilities based on their sex assigned at birth or sent to designated "unisex" restrooms that are not used by other students.

This may increase the potential for sexual assault in bathrooms and locker rooms, the study authors note. It may also make assault and victimization more likely in other locations by creating a climate that's hostile to sexual minority youth.

Participants in the study were 15 years old on average. Overall, 26 percent of them reported experiencing sexual assault in the previous year. At schools with restrictive bathroom and locker room policies, that rate climbed to 35 percent.

Story continues

Sexual harassment appeared to explain the increased risk of assault associated with bathroom and locker room restrictions. the study also found. It's possible that this is because harassment often escalates to assault, and it is also possible that both experiences occur more often when schools don't discipline this behavior or create an environment where students feel safe reporting it.

The study wasn't a controlled experiment designed to prove whether or how bathroom policies might directly contribute to sexual assault.

One limitation of the study is that it didn't include enough black or Hispanic students to assess how race or ethnicity might impact the risk of sexual assault or harassment, the study authors note. The study also had too few students who identified as nonbinary but were assigned male at birth to get precise estimates of the assault risk for these teens.

In an editorial, Dr. Stephen Rosenthal and Diane Ehrensaft, both of the University of California, San Francisco, point out that California is the only state that requires schools to let students use facilities that match their gender identity rather than their sex assigned at birth - and the new study didn't look at the assault risk of trans and nonbinary teens in that state.

Even so, the results add to the evidence suggesting that failure to support trans and nonbinary youth can endanger both their physical and mental health, Rosenthal and Ehrensaft write.

"Transgender youth who express their gender identity but are required to use facilities matching their genitalia are not only at risk for verbal and physical harassment, including sexual abuse, but, not surprisingly, some will avoid using restrooms altogether, resulting in increased risk for inadequate fluid intake, urinary retention, urinary tract infections, impacted bowels, and school avoidance," they write.

SOURCE: http://bit.ly/2DTfSiF Pediatrics, online May 6, 2019.