Last week’s new “Policy on the Protection of the Female (Women’s) Category in Olympic Sport” has been discussed mainly in relation to transgender athletes, but medical experts and Olympians say its effects will be felt more by those with Differences in Sexual Development (DSD).
Laurel Hubbard of New Zealand is the only recorded trans athlete in Olympic history; the weightlifter failed to record a successful lift in the women’s +87kg event at the delayed 2020 Games. South Africa’s Caster Semenya was barred from defending her 800m title after World Athletics required women with higher testosterone to reduce levels below 5 nmol/L for six months—a rule Semenya refused to follow.
Testosterone levels have long defined eligibility debates for athletes who do not fit neatly into male or female categories.
The IOC policy makes a rare exception for athletes with Complete Androgen Insensitivity Syndrome (CAIS) or other rare DSDs who “do not benefit from the anabolic and/or performance-enhancing effects of testosterone.” Otherwise, it returns to SRY testing—a cheek swab used in the 1990s—to detect the SRY gene on the Y chromosome.
Semenya called the decision a “disgrace” in a Time article, writing: “Genetic screening is not, and never has been, a way to protect girls and women in sports. To call it that is to mask a monster. Let’s call this what it is: exclusion, just with a different name.”
Under former IOC head Thomas Bach, the organization said there was “no one-size-fits-all solution” to gender testing. A 2023 report by multiple scientists noted that in events relying on endurance, strength, speed and power, men typically outperform women because of sex differences set at puberty, particularly testosterone.
While trans athletes are widely argued to have distinct advantages, cases involving DSD are more complex. DSD involves natural variations in genes, hormones and reproductive organs; transgender people have an identity that may not align with their sex and may pursue medical transition.
Semenya and boxer Imane Khelif—who won gold at Paris 2024—both have DSD. Professor Alun Williams, a sports scientist at Manchester Metropolitan University, told the BBC the policy risks marginalizing such athletes. He warned of ethical problems in genetically screening many people, including minors, and of revealing life-changing biological information. He added that reverting to a 1990s system that reduces sex to one gene is an oversimplification, and that evidence of advantage for people with DSD, even with a Y chromosome, is disputed.
The IOC now mirrors World Athletics. After World Athletics changed its rules last year, Semenya said she felt targeted. She argued that being born with differences does not make someone a great athlete—training, dedication and hard work do.
World Athletics chief Sebastian Coe introduced the earlier rule; IOC president Kirsty Coventry implemented the new policy and defended it as based on science and fairness. Coventry said it would be unfair for biological males to compete in the female category and that in some sports safety is a concern. She said athletes would be screened once in their lifetime, with education, counselling and expert medical advice available.
Semenya, who was invited to give input when the IOC considered the ban, expressed disappointment with Coventry: “Like me, IOC President Kirsty Coventry is a woman from Africa. I hoped she would be different,” she wrote. “Instead, she failed us.”
Edited by: Chuck Penfold