Semenya lost her case, in the
Court of Arbitration for Sport on 1 May 2019. During proceedings it was revealed that Semenya has
5α-reductase deficiency, to exclude
the XX DSD CAH, and released an accompanying statement and FAQ explaining that the regulations ONLY apply to individuals with XY DSDs and testes. These new rules came into effect on 8 May 2019. The legal case divided commentators such as Doriane Coleman, who testified for the IAAF, arguing that women's sport requires certain biological traits, from commentators such as Eric Vilain, who testified for Semenya, arguing that "sex is not defined by one particular parameter ... for many human reasons, it's so difficult to exclude women who've always lived their entire lives as women — to suddenly tell them 'you just don't belong here.'" Semenya appealed the decision to the
Federal Supreme Court of Switzerland. On 3 June 2019, the Swiss Federal Supreme Court advised that they had "super-provisionally instructed the IAAF to suspend the application of the 'Eligibility Regulations for the Female Classification for athletes with differences of sex development' with respect to the claimant [Semenya]" until the court decides whether to issue an
interlocutory injunction. On July 30, 2019, the Swiss Federal Supreme Court reversed its earlier ruling that had suspended the Court of Arbitration for Sport decision and the IAAF rules. For that reason, Semenya, silver medalist
Francine Niyonsaba and Olympic bronze medalist
Margaret Wambui missed the
2019 World Athletics Championships in Doha in October 2019, while continuing legal appeals. The number 3 ranked 400 meter runner for 2019,
Aminatou Seyni had to switch events to a weaker event, the
200 metres, in order to adhere to this rule. On September 8, 2020, the Swiss Federal Supreme Court issued a ruling denying Caster Semenya's appeal. In November 2020 Semenya announced that she will file an appeal against the IAAF testosterone rule at the
European Court of Human Rights. In July 2019, Semenya said that the ongoing issue has "destroyed" her "mentally and physically". ==At the 2020 Olympics==