The decision by the IOC (International Olympic Committee) to adopt genetic tests to determine the participation of athletes in female categories at the Olympic Games is political and is not supported by solid scientific evidence.
This is the assessment of Bruno Gualano, professor at FMUSP (Faculty of Medicine at the University of São Paulo) and columnist for Sheet.
Having led a meta-analysis last year that compiled 51 studies already published on the topic, encompassing 6,400 participants, Gualano stated that the measure, which aims to restrict the female category to biologically female athletes, vetoing the inclusion of trans athletes, must be interpreted within the current context of sport and international geopolitics, which involves broader disputes about gender.
“The IOC’s decision is influenced by the political and social scenario, which is unfavorable to the rights of trans people,” said Gualano.
Under criticism from LGBTQIA+ and human rights groups, sports entities, international federations and governments have been promoting a tightening of rules on the participation of transgender women in sporting competitions and events over the past few months.
The allegation is that the actions aim to preserve justice in the female category and are based on supposed competitive advantages in relation to cis athletes, due to exposure to testosterone when they still identify with the male gender.
For the USP researcher, the scientific literature that supports this type of policy is still limited and does not prove a supposed physical advantage for trans athletes compared to cis competitors in the female category.
“The studies on this are scarce and, to a large extent, outdated,” he stated. It also highlights the lack of consistent empirical data, which would make more robust analyzes difficult. According to the IOC, trans athletes represent less than 0.001% of high-performance athletes.
The test model announced this Thursday by the Olympic Committee is based on the detection of the SRY gene, associated with the Y chromosome, through genetic analysis, generally from saliva samples.
The problem with the method, according to the researcher, is that, although the detection of SRY is technically accurate, there are limitations in its interpretation. This is because the presence of the gene does not necessarily guarantee that it has significant functional expression in the organism.
This factor does not allow conclusions about the possible competitive advantage of trans women over cisgender women, according to Gualano. He explained that there are rare biological conditions in which the Y chromosome may be present in individuals with a female phenotype. “This shows that the test, alone, is insufficient to classify athletes or estimate competitive advantage”, he argued.
The IOC indicated the decision that trans women will have to compete in the men’s category at the next Olympics. “Athletes who test positive on the SRY test, including XY transgender athletes and XY-DSD athletes with androgen sensitivity, continue to be included in all other classifications for which they qualify. For example, they are eligible for any men’s category, including a designated men’s spot in any mixed category, and any open category, or in sports and events that do not classify athletes by sex,” says an official note from the Committee.
IOC President Kirsty Coventry defended the decision. “As a former athlete, I strongly believe in the right of all Olympic athletes to participate in fair competition. The policy we announced is based on science and was led by medical experts. At the Olympic Games, even the smallest margins can be the difference between victory and defeat. Therefore, it is absolutely clear that it would not be fair for biological males to compete in the female category. Furthermore, in some sports, it simply would not be safe.”
Historically, the IOC abandoned universal sex testing after the 1996 Atlanta Games and, since 2021, it has been adopting more flexible guidelines, delegating the definition of rules to federations. For Gualano, the resumption of a single genetic criterion represents a methodological step backwards.
