Gender, as much as societal norms want us to believe it, isn't always a black and white issue. The issue hit the headlines last year when South African runner Caster Semenya's sex came into question after she won gold in the 800 meters event during the World Championships.
Both the International Olympic Committee and the International Association of Athletics Federations admitted their policies weren't always clear when it came to this sort of thing.
"Sometimes you come across cases that are uncertain and ambiguous, and it changes from being a sports matter to a medical matter," IOC medical commission chairman Arne Ljungqvist told the Associated Press in October. "That's where we need to have a review."
The IOC has invited medical experts to draw up guidelines for dealing with "ambiguous" gender cases during a conference in Miami Beach next week.
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Semenya, in the meantime, has been allowed to keep her medal and prize money, and her coach says that she's been cleared to compete internationally as a female. Her lawyer however says that the negotiations are ongoing and may be impacted by next week's conference.