A doctor has claimed that there’s no existing evidence that transgender girls perform better in sports than cisgender girls.

Dr Veronica Ivy said in an interview with TMZ Live that the data that is currently available does not prove that transgender girls have the advantage when it comes to competing in sports with cisgender girls.

Dr Ivy added that until there’s enough data proving the claim, transgender girls should be allowed to participate in sports with cisgender girls.

However, the doctor did acknowledge that there is a difference in terms of performance between biologically-born boys and girls in sports, but the reason is just speculation.

“The truth is, we don’t know what makes men better at sports compared to women,” Dr Ivy told TMZ Live. “But we do know now, finally, after all these years, that it isn’t as simple as natural testosterone.”

“That is not the reason,” she added. “There are elite world championship level men with natural testosterone below the women’s average, and they’re competing at no disadvantage to men with 100 times as much testosterone.”

“So there are certainly, maybe, some biological reasons for men, on average, being bigger, stronger, faster than women, but we do know that there are also social reasons.”

The doctor went on to explain that competing in sports is a ‘human right’ and that the ongoing issues transgender people are facing is because people continue to compare men to women and girls to boys, instead of transgender women to cisgender women, and so on.

“If we’re talking about trans girls in girl’s sport, then we have to talk about the difference between trans girls and cisgender girls, not boys and girls,” she explained.

Dr. Ivy’s comments came after some US states banned transgender girls from competing in girl’s sports out of concerns that it is simply not fair. Lawmakers believed that transgender girls will always have the upper hand.

It also comes after Caitlyn Jenner, who is a transgender woman herself,  said that biologically-born boys shouldn’t be able to compete in girl’s sports.

“This is a question of fairness,” Jenner said. “That’s why I oppose biological boys who are trans competing in girls’ sports in school.”

“It just isn’t fair,” Jenner added. “And we have to protect girls’ sports in our schools.’”