World Athletics has approved SRY gene tests for athletes wishing to compete in the female category, with the regulations taking effect on 1 September 2025 ahead of the World Championships.
All athletes wishing to compete in the female category at the World Championships in Tokyo, which take place between 13-21 September, will be required to undergo a once-in-a-lifetime test, either through cheek swab or a blood test, for the SRY gene - a reliable proxy for determining biological sex.
Commenting on the new regulations and SRY test, World Athletics president Sebastian Coe said: “The philosophy that we hold dear in World Athletics is the protection and the promotion of the integrity of women's sport.
"It is really important in a sport that is permanently trying to attract more women that they enter a sport believing there is no biological glass ceiling. The test to confirm biological sex is a very important step in ensuring this is the case.
“We are saying, at elite level, for you to compete in the female category, you have to be biologically female. It was always very clear to me and the World Athletics Council that gender cannot trump biology."
World Athletics conducted consultation on the proposal earlier this year, which Coe previously stated was "widely held" and "exhaustive" and had received feedback from over 70 individual groups.
The consultation document stated: "The childhood or pre-pubertal performance gap in the sport of athletics specifically is three to five per cent in running events and higher in throwing and jumping events."
Asked whether he felt the policy would stand up to legal challenge, he said: "Yes I am, but you accept the fact that that is the world we live in.
"I would never have set off down this path to protect the female category in sport if I'd been anything other than prepared to take the challenge head on.
"We've been to the Court of Arbitration on our DSD (difference of sexual development) regulations. They have been upheld and they have again been upheld after appeal.
"So we will doggedly protect the female category and we'll do whatever is necessary to do it."
The SRY gene test will be taken via cheek swab or blood test, whichever is more convenient.
The SRY gene is almost always on the Y chromosome, which plays a crucial role in determining male sex characteristics.
The working group said there was now evidence that testosterone suppression in DSD and transgender athletes could only ever partly mitigate the overall male advantage in the sport of athletics.
In the short term and for the World Athletics Championships Tokyo 25, member federations will be conducting the tests for their athletes.
Newly-elected International Olympic Committee president Kirsty Coventry, , told Sky News after her appointment that she was not ruling out sex testing, saying: "This is a conversation that's happened and the international federations have taken a far greater lead in this conversation.
"We know in equestrian sex is really not an issue, but in other sports it is.
"So what I'd like to do again is bring the international federations together and sit down and try and come up with a collective way forward for all of us to move."
The IOC introduced "certificates of femininity" at the 1968 Mexico Olympics but those chromosome-based tests were deemed unscientific and unethical and dropped ahead of the Sydney Games in 2000.
Reem Alsalem, the UN's special rapporteur on violence against women and girls, last year called on the IOC to reintroduce sex testing for female athletes to protect them from injuries amid concerns about eligibility.
Sex testing would have had no impact on the boxing controversary during the Paris 2024 Olympics.
