SRY Gene Screening: The Return of Sex Testing

Timeline

1. 1968Chromosome testing of women athletes begins at the Olympic Games.
2. 1999The IOC votes to end routine sex testing; it was last carried out in 1996.
3. Jul 2015CAS suspends the IAAF's hyperandrogenism rules in the Dutee Chand case.
4. Aug 2024Imane Khelif wins Olympic boxing gold in Paris amid a public dispute over her eligibility.
5. May 30, 2025World Boxing announces mandatory genetic sex testing.
6. Sep 1, 2025World Athletics' SRY gene test requirement takes effect before the Tokyo World Championships.
7. Mar 26, 2026The IOC announces a policy limiting women's events to biological females from LA 2028, based on SRY screening.

The ethical issues

• Fairness and safety in the women's category.
• Accuracy: what an SRY test shows and does not show.
• Privacy and consent: genetic testing of all women athletes.
• Differences of sex development: athletes who test positive but were raised as women.
• History: earlier sex testing that humiliated and misclassified women.

Stakeholders

Stakeholder	Interests & obligations
Women athletes	Fair competition, safety, privacy and dignity.
Athletes with differences of sex development	Eligibility and protection from stigma.
Transgender athletes	Their eligibility in the women's category.
International federations and the IOC	Defining and enforcing eligibility.
Medical professionals	Ethical testing, counseling and confidentiality.
National governments	Laws that may restrict genetic testing.

The case

International sport has tried for decades to verify who may compete as a woman. In the 1960s, some events used visual inspections, which athletes found humiliating. From 1968, women at the Olympics had to pass a chromosome test, the Barr body test, using cells from a cheek swab.^[1] Scientists criticized it for misclassifying women with certain genetic conditions. In 1985, Spanish hurdler María José Martínez-Patiño failed the test and was pressured to retire quietly. She fought the decision and was reinstated.^[1] In 1992, the IOC switched to a DNA-based test for male genetic material. Routine testing was last carried out at the 1996 Atlanta Games, and the IOC ended it in 1999.^[1]

In the years that followed, sports bodies turned to testosterone-based rules, which were challenged by athletes including Dutee Chand and Caster Semenya.^[1]

Background

The history of sex testing goes back further than the 1960s. Avery Brundage, later IOC president, asked during or shortly after the 1936 Berlin Olympics for a system to examine female athletes.^[1] From 1958 to 1992, all women had to undergo mandatory sex verification before IAAF or IOC events.^[1] In 1967, the IOC disqualified Erik Schinegger, the 1966 women’s world downhill champion, from the 1968 Winter Games after determining that he had internal male sex organs.^[1]

Scientific objections built up over time. Finnish geneticist Albert de la Chapelle argued for years that the Barr body test wrongly identified intersex women and ignored gonadal, anatomical and psychological aspects of sex.^[1] Conditions that complicated testing included androgen insensitivity syndrome, gonadal dysgenesis, Turner syndrome and congenital adrenal hyperplasia.^[1] With de la Chapelle’s support, Martínez-Patiño was reinstated by the IAAF in 1988, and her case and advocacy helped end chromosome testing.^[1]

The rules and governance

Previous testing regimes ended through scientific and ethical pressure. The 1992 switch was to a polymerase chain reaction (PCR) test looking for “male-related genetic material” in a cheek swab.^[1] A 1996 IOC World Conference on Women and Health passed a resolution “to discontinue the current process of gender verification during the Olympic Games,” and the IOC board voted to end it in June 1999.^[1] The new SRY screens are also PCR-based tests, but this time for a single gene.^[2][3]

The testosterone era raised its own concerns. In 2012, the IOC adopted regulations on female hyperandrogenism, and national Olympic committees were asked to “actively investigate any perceived deviation in sex characteristics.”^[1] A case published in 2013 described four unnamed women athletes from poor rural regions who were identified with differences of sex development and underwent treatment that included gonadectomy. The case became a focus of ethical criticism of eligibility screening.^[1] The IOC itself has said that requiring surgical changes as a condition of participation may be considered a human rights violation.^[1]

World Boxing

At the 2024 Paris Olympics, Algerian boxer Imane Khelif won gold in the women’s welterweight division amid a public dispute over her eligibility. She had been disqualified from the 2023 world championships by the International Boxing Association, which the IOC no longer recognized.^[1][6] In May 2025, World Boxing, the sport’s new international federation, announced mandatory genetic sex testing for adults entering its competitions. All boxers over 18 would need a PCR genetic test; those with the SRY gene would compete in the men’s category.^[3] Khelif appealed to CAS. CAS declined to suspend the rule while the appeal was pending, and she missed the 2025 world championships.^[6] Her appeal also asked CAS to declare her eligible for the September 2025 championships without a test. World Boxing apologized for naming her in its announcement of the testing policy.^[6] She has always competed in the women’s division.^[6]

World Athletics

World Athletics introduced a “once-in-a-lifetime” test for the SRY gene, which normally sits on the Y chromosome and triggers male development. It described the gene as “a reliable proxy for determining biological sex.” The test uses a cheek swab or blood sample and is overseen by national federations. The rules took effect on September 1, 2025, before the Tokyo World Championships.^[2] President Sebastian Coe said: “We are saying, at elite level, for you to compete in the female category, you have to be biologically female… gender cannot trump biology.”^[2]

The regulations followed a Gender Diverse Athlete Working Group that studied the issue for more than a year. It recommended merging the separate DSD and transgender rules and adopting “a pre-clearance requirement for all athletes competing in the female category.”^[2] The resulting eligibility rule lists who may compete as women. Beyond biological females, it includes those who used testosterone for male gender-affirming treatment, but only after a period of at least four years set case by case. It also covers biological males with complete androgen insensitivity syndrome and athletes with a DSD who meet transitional provisions. Those provisions, the federation said, do not apply to transgender women, because “there are none competing at the elite international level.”^[2] World Athletics paired the rule with four commitments: it “does not judge or question gender identity,” it respects “dignity and privacy,” it observes confidentiality and data protection law, and it “never has and never would impose any obligation to undergo surgery.”^[2]

The IOC

On March 26, 2026, IOC President Kirsty Coventry announced a new policy. From the 2028 Los Angeles Games, women’s events at IOC competitions will be limited to biological females, determined by a one-time SRY screen. There is an exemption for athletes with complete androgen insensitivity syndrome, who do not go through male puberty. Athletes who screen positive remain eligible for other categories. The IOC said test results would not be applied retrospectively and the policy did not apply to grassroots or recreational sport. Coventry said every athlete “must be treated with dignity and respect” and called for counseling and expert medical advice.^[4][5] She said it “would not be fair for biological males to compete in the female category,” and that “in some sports it would simply not be safe.” The IOC described SRY screening by saliva, cheek swab or blood as “unintrusive compared to other possible methods.”^[5] It said its working group had reviewed evidence for 18 months and found a “clear consensus” that “male sex provides a performance advantage in all sports and events that rely on strength, power and endurance.” Its consultation drew more than 1,100 athlete survey responses.^[5]

Aftermath

The IOC’s decision ended its practice of leaving female eligibility to each international federation, and it expected federations to follow.^[5] Objections came quickly. The French Olympic Committee said SRY tests “raise major ethical and scientific concerns.” It added that in France such testing would conflict with bioethics law and the civil code. A group of academics, in a report submitted to the British Journal of Sports Medicine, called sex testing “a backwards step and a harmful anachronism.”^[5] Opponents also cited cost, invasiveness and the risk of contamination and false positives. Supporters called the test reliable, confidential and proportionate.^[5]

The core dilemma

Supporters of screening say sex-based categories exist because of physical differences that develop at male puberty, and a simple genetic test protects fairness and safety for women. Critics say universal genetic testing intrudes on privacy and risks stigmatizing women with rare conditions, many of whom may not know about them. Can screening be fair to all women?

Competing values

• Fairness and safety vs. privacy: protecting the category against intrusion on every athlete.
• Clarity vs. nuance: a bright-line test against complex biology.
• Uniform rules vs. individual circumstances: consistency against case-by-case exceptions.
• Learning from history vs. new tools: past harms of testing against improved science.

Strongest arguments

For screening: testing everyone once is less stigmatizing than targeting individuals based on appearance or performance. The SRY test is simple and reliable for its purpose, and protects women’s opportunities and safety, especially in combat sports.

Against screening: the test detects a gene, not performance or advantage. Women with differences of sex development may face distressing results and public exposure. Some national laws restrict genetic testing without medical purpose, and history shows the harm of such programs.

Applying the frameworks

Justice

A justice lens asks what fairness in the women’s category requires, and whether a single genetic screen draws the line fairly. Rawls’s veil of ignorance asks decision-makers to design the rule without knowing whether they would be a typical female athlete, an athlete with a difference of sex development, or a transgender athlete.

Rights

A rights lens centers privacy, bodily integrity and informed consent in genetic testing. It asks how organizations protect test results, provide counseling and avoid the public humiliation that past regimes caused, while respecting women athletes’ claims to fair competition.

Kantian (duty)

A Kantian lens asks whether a universal screening rule treats every athlete as an end in herself. It considers whether testing everyone, rather than targeting individuals by appearance, is more respectful. It also asks whether excluding athletes with no choice over their genetics is consistent with dignity.

Walk it through: the Simple Decision Model

1. Spot the issue. You are a member of a federation’s medical commission designing an SRY screening program for the women’s category. The stakeholders include all women athletes, athletes with differences of sex development, transgender athletes, coaches, national federations and the public. The codes in play are federation eligibility rules, privacy law and medical ethics.
2. Gather facts. What does the science say about the test’s accuracy and what it does and does not measure? What are the exemptions? How will results be stored and communicated?
3. Test options. Options: (a) universal screening with exemptions and counseling; (b) screening only when there is reason for concern; (c) no screening, using other eligibility criteria. Weigh fairness in competition against privacy, dignity and the risk of harm.
4. Check codes and law. Would you accept this process if you or your child were tested? Does it avoid the humiliation of past regimes?
5. Decide and document. Record the rationale, the evidence and the safeguards.
6. Communicate and follow up. Communicate the policy clearly to athletes in advance, provide confidential counseling and an appeal route, and review the policy as evidence develops.

What’s settled and what’s contested

• Settled: the World Athletics, World Boxing and IOC policies and their dates.
• Contested: whether SRY screening is accurate and fair enough; how exceptions will work; the outcome of legal challenges.

Why this case matters

The return of sex testing reverses a decades-long trend in Olympic sport. How these policies are implemented will shape the experience of every woman athlete and the definition of the women’s category.

Key terms

Distributive justice

Fairness in how scarce opportunities, resources, benefits and burdens are shared.

Consent and autonomy

Whether people have agreed freely and with full information, and whether their right to make their own choices is respected.

Paternalism (hard and soft)

Restricting someone’s choices for their own good. Hard paternalism overrides competent, informed adults; soft paternalism steps in when information or autonomy is compromised.

Veil of ignorance

Rawls’s test for fair rules: design the policy as if you did not know which position you would end up in.

Definitions from the Ethics Cases glossary.

Discussion questions

1. Sport abandoned routine chromosome testing in 1999 after decades of criticism. What, if anything, makes SRY screening different?
2. Is it fair to require genetic tests of all women athletes to address a small number of cases? Why or why not?
3. How should sport treat athletes who test positive for SRY but were raised as girls and may not have known about their condition?
4. Should international bodies impose genetic testing where national laws restrict it?
5. What would a respectful process for athletes who fail a screening test look like?

Sources

1. Sex verification in sports — Wikipedia
2. World Athletics introduces SRY gene test for athletes wishing to compete in the female category — World Athletics
3. World Boxing to introduce mandatory sex testing for all boxers that want to participate in its competitions — World Boxing
4. International Olympic Committee announces new Policy on the Protection of the Female (Women's) Category in Olympic Sport — IOC
5. Women's Olympic sports limited to biological females from 2028 – IOC — BBC Sport
6. Imane Khelif: Olympic champion appeals to Cas over World Boxing's decision to introduce genetic sex testing — BBC Sport