Public school superintendents in Texas approved a measure that requires student athletes to present their birth certificate to determine their gender.

A referendum ballot saw the measure passing with a 586-32 vote that aims to separate girls from boys when it comes to athletic competitions.

"Member schools may not permit boys to try out for or participate under the jr. high school or high school athletic plans designated for girls' teams," the new policy reads, according to the Christian News Network. "Member schools that offer cross country, golf, swimming, tennis, track and field and/or wrestling individual athletic plans may not permit mixed plans for boys and girls."

It says gender will be determined based on a student's birth certificate but when it is not available, other similar government documents may be used as substitute.

The new rule also says, "Boys may not wrestle against girls, and vice versa. This prohibition is only applicable when the contest is held in Texas or in any other state that sponsors wrestling programs for both boys and girls."

Brad Thiessen, athletic director at Amarillo Independent School District, told KFDA-TV that the reason for the new rule "is to just create a level playing field and to make sure that nobody gains an advantage."

"With that kept in mind, the birth certificate is the easiest way to determine gender," he said.

University Interscholastic League (UIL) policy director Jamey Harrison told the Baptist Press that "when we were asked by a school for guidance, that was the recommendation we gave them, although we told them to work through their own process and own legal counsel as well."

Peter Sprigg, senior fellow for policy studies at the Family Research Council (FRC), praised the policy.

"Our position at FRC is that government entities, including schools, have no obligation to recognize a change in gender identity from the biological sex at birth. This is especially important when it comes to athletics because there are undeniable physical differences between the sexes," he said.

He added, "From a Christian perspective, the Bible says several times 'male and female He created them' and this is a part of the created order. From a theological perspective, to seek to change one's gender is a rebellion against God's created order."

However, the rule has been criticised by transgender groups, saying it's discriminatory.

"At the high school level, we should be encouraging participation for all students," Chris Mosier, founder of TransAthlete.com, told the Associated Press. "Texas school leaders have a responsibility to ensure that transgender athletes can participate in a way that is safe, comfortable and affirming of their identity."

The new policy will take effect on Aug. 1.