The IAAF has approved new regulations regarding the eligibility of females with hyperandrogenism to compete in women's athletics. It follows an IAAF Council rules review resulting from the gender row over South Africa's Caster Semenya. Semenya won the 800m at the 2009 World Championships in Berlin, but was then sidelined as the IAAF investigated her high testosterone levels. The rules will be enforced from 1 May and apply to all international events. Hyperandrogenism causes abnormally high levels of androgens [testosterone] and a female athlete with the condition could, under the previous regulations, be prevented from competing, as was the case with Semenya. She has since returned to competition, but the episode lead to the IAAF Council commissioning a review which has taken 18 months to complete. Testing levels for men and women differ because males naturally produce more androgens. A female athlete will be permitted to compete in women's competition if their androgen levels are below the male range. If a female athlete has androgen levels within the male range, they may compete if they have an androgen resistance, which would reduce any competitive advantage. The IAAF has appointed a panel of international medical experts to review cases of female athletes with hyperandrogenism. They will operate independently of the IAAF and will make recommendations to the governing body over athletes' eligibility for competition. Tests to determine a female athlete's eligibility for competition will be conducted at one of the IAAF'S approved specialist reference centres upon referral from the expert medical panel. Athletes referred can expect a full medical examination, and those who refuse will be banned from competing in women's athletics competition. Source: BBC