Until recently, most laypeople were unfamiliar with the medical term “differences in sex development” (DSD). Only now, after a gender furore engulfed women’s boxing at the Olympics, has DSD come under the spotlight.
Algerian boxer Imane Khelif, 25, and 28-year-old Taiwanese boxer Lin Yu-ting were disqualified from the 2023world championships run by the International Boxing Association after failing to meet “eligibility criteria”.
However, both competed in the Tokyo Olympics three years ago and were cleared to fight in Paris.
The rare condition was previously known as disorders of sex development, or “intersex” conditions.
Dr Ashley Grossman is an emeritus professor of endocrinology at the University of Oxford. He says: “Simply put, the development of sexual differentiation is an amazing and complex process in the womb, with the vast majority of people being biologically, sexually and in terms of appearance, male or female.
South African runner Caster Semenya only learned she had a DSD during pre-competition medical tests. Photo / AAP
“Yet sometimes things work out a little bit differently and previously unpleasant, insulting terms such as ‘hermaphrodite’ were used to describe these affected people.”
How many people does it affect?
Grossman estimates that DSD affects between just 0.05 and 1 per cent of the population. The condition is generally diagnosed at birth, when a baby’s genitalia might not be obvious.
The British charity DSD Families estimates that around 130 babies born in the UK each year need investigations for potential intersex conditions. Worldwide, up to 1.7 per cent of people have intersex traits (roughly the same proportion of the population who have red hair).
“[DSD] is generally not picked up in the womb, so it can be sensitive for parents who discover this difference when [their baby is] born,” Grossman explains.
“It used to be, 20 or 30 years ago, if there was ambiguity down there, doctors would decide to make the baby a girl, which seemed most convenient. But since then we have realised it’s more complicated than assigning a gender, as there are also hormones at play.”
When is DSD diagnosed?
While most DSDs are spotted at birth, some only come to light in puberty or as a result of a medical operation, test or even an autopsy.
In rare cases, athletes have only learned they have a DSD during pre-competition medical tests, after which they are disqualified. South African runner Caster Semenya is a famous example.
“Today, most good endocrinologists or paediatricians explain that there’s a lack of clarity to parents, carry out all the relevant tests, and proceed in terms of surgery and hormones with what looks to be the most appropriate and comfortable outcome for that child,” Grossman says.
What causes DSD?
It's not known what triggers most cases of DSD. Photo / 123RF
In most cases of DSD, what exactly triggers it during development in the womb is unknown. “There are suggestions that disruptors in the environment, or pollutants or plastics of some form, might cause any changes during development, but these are very speculative,” Grossman says.
“I think the major risk factors are genetic, and it may not ‘run in the family’ as such – because if there were recessive genes in both parents, then this could happen when there hasn’t been any previous family history.”
Grossman suggests issues become complicated – and controversial – only when it comes to competitive sports. For example, when a person can be born with female genitalia, but have the XY chromosome combination typical of males, as well as internal hidden testicles.
In the context of sport, an unusual combination of chromosomes and reproductive organs can boost people’s performance.
“Extra male hormones, particularly during puberty, will give a clear advantage with certain sports, such as boxing,” explains Grossman. “It’s complex because someone can absolutely be a biological woman, but if they went through puberty as a male, there would be performance advantages. A DSD would likely boost her level of testosterone, a hormone critical to building muscle and strength, and which would increase stamina.
“While these changes are often only small, they become significant with elite sports when a tenth of a second in running – or a slightly more powerful punch as we saw with Khelif – the effects and outcomes can be major.
“I can totally understand why women competing with others who have male hormones feel it’s unfair. What happened in this case is that the local committees made decisions about how to regulate and the IOC failed to regulate them on an international basis, so there was a very unequal playing field.”
What is life like for most people with DSD?
For the vast majority of DSD patients, “life can be normal”, Grossman says, and even parenthood isn’t out of the question.
“Whether male to female, or female to male, as long as my patients are happy with their hormones and treatment, then I am pleased that we have succeeded in helping them. However, I have no patients in competitive sport, so this is a totally different situation.”
