The World Athletics Council (WAC) has announced new rules on the participation of transgender athletes.
Under the changes unveiled on Thursday, trans-identifying biologically male athletes will no longer be able to compete in the female category in international athletic events.
The WAC said it wanted to "prioritise fairness and the integrity of the female competition before inclusion".
WAC President, Lord Sebastian Coe, said, "The World Athletics Council has taken decisive action to protect the female category in our sport."
The decision affects male-to-female transgender athletes who have been through male puberty.
They will be excluded from female world ranking competitions from 31 March.
"The decision that the council made is a primarily principle-based decision and that is the overarching need to protect the female category. This is what our sport is here to do," Lord Coe said.
The WAC had initially proposed tightening up the restrictions for transgender athletes by requiring them to reduce testosterone levels from 5 nanomoles per litre to 2.5 over a two-year period.
A consultation found widespread opposition to this proposal.
"The majority of those consulted stated that transgender athletes should not be competing in the female category," Lord Coe told reporters.
"Many believe there is insufficient evidence that trans women do not retain advantage over biological women.
"Where the science is insufficient to justify maintaining testosterone suppression for transgender athletes, the council agreed it must be guided by our overarching principle, which is to protect the female category."
