What is DSD and what’s the debate over athletes in the Olympics?

• Boxers compete in Olympics after previous gender test fail
• Games fans debate on athletes with intersex traits
• Multiple intersex athletes have competed in the Olympics

LONDON - The inclusion of two women boxers at the Paris Olympics who were peviously barred from an international contest after failing gender checks has spurred fresh debate on the inclusion of athletes whose bodies fall outside female gender norms.

Imane Khelif, representing Algeria, and Lin Yu-ting, from Taiwan, are both competing in this year's Games, having previously been disqualified from the 2023 World Championships in Delhi for failing unspecified gender eligibility tests. 

Olympics organisers The International Olympic Committee (IOC) said both Khelif and Yu-ting are eligible to compete in the women's category, and pointed out the boxers also participated in the 2021 Tokyo Games.

Their inclusion has thrown a spotlight on debates over whether athletes with Differences of Sexual Development (DSD)  should be included in female sports categories - though neither Khelif or Yu-ting have commented on whether they have DSD.

Here is everything you need to know.

Why is there debate over how to include DSD athletes?

DSD is an umbrella term for a group of conditions where people's bodies chromosomes or hormones don't fit usual expectations of male or female. 

Around 1.7% of children are born with DSD, according to the United Nations. 

Some people with DSDs have female genitalia but have XY sex chromosomes and/or blood testosterone levels in the male range.

That has led to debate around their inclusion in women's sport, with critics saying higher testosterone and other physical differences could give them an unfair advantage - and may be unsafe in the case of contact sports.

Advocates for athletes with DSD have said they should not be penalised for their natural bodies, as many sporting champions - such as swimmer Michael Phelps - have succeeded due to their physical advantages, such as being tall, strong or double-jointed.

The governing bodies of athletics, cycling, swimming and rugby union have tightened their regulations to exclude people who have gone through male puberty or who have unusually high testosterone levels from competing in female categories.

Which other intersex and DSD athletes have competed?

South African track runner Caster Semenya has been the centre of the debate surrounding athletes with DSD since 2009.

In her memoir, Semenya said she learned she had intersex traits following a World Athletics examination, which found she had XY chromosomes and high levels of testosterone. 

The two-time Olympics champion has not been allowed to take part in any race between 400m and a mile since 2018 unless she lowers her natural testosterone levels through medication or surgery. 

Semenya challenged World Athletics' decision at the European Court of Human Rights, and a final ruling is expected before the end of the year. 

During the Tokyo Olympics, Namibian runners Christine Mboma and Beatrice Masilingi were banned from racing in distances 400m to one mile due to their high levels of natural testosterone.

The pair were allowed to take part in the 200m, with Mboma gaining a silver medal. 

Zambian footballer Barbra Banda has also taken part in the Paris Olympics, though she was ruled out of 2022 Africa Cup of Nations for failing gender eligibility tests.

Burundian runner Francine Niyonsaba won a silver medal in the 800m at the 2016 Rio Games, and three years later took a 2,000 metres world record, reportedly becoming the first athlete with DSD to break a world record. 

She has since changed to running longer distances, due to World Athletics rules.

What have athletes said about people with DSD?

The inclusion of Khelif and Yu-ting spurred a backlash from some other athletes. It also brought forth fresh criticism against transgender inclusion and entirely unconfirmed speculation that the boxers were trans or had gone through male puberty.

"People not born as biological woman, that have been through male puberty should not be able to complete in women's sport. Not only is this unfair it's dangerous," British boxer Nicola Adams said in a statement shared on X on Friday. 

Australian boxer Caitlin Parker said: "Biologically, genetically, they're going to have more advantages, and in combat sports, it can be dangerous." 

However, fellow Australian boxer Tiana Echegaray said she would be "not cool with fighting a man. But in their case, I can't say specifically on them because I don't know their scenario or situation."

Italian boxer Angela Carini, who ended her fight against Khelif after 46 seconds in the ring, told Italian media the controversy over her opponent's gender had made her "sad".

"If the IOC said she can fight, I respect that decision," Carini told Gazzetta dello Sport, according to the BBC.

Athletes with DSD, such as Semenya, have been outspoken in their battle for inclusion in sport. 

"I don't think this is about my career. It is about me being an advocate for what is right, to voice out for those who cannot fight for themselves," Semenya told reporters at the European Court of Human Rights this year.

Niyonsaba said she "did not choose" to be born with DSD, in an interview after winning her silver medal in 2016 and said she would not stop running.

"I am created by God, so (if) someone has more questions about it, maybe (they) can ask God," she said. 

(Reporting by Lucy Middleton; editing by Sonia Elks.)