The swimming world governing body, FINA, just voted to restrict the participation of transgender athletes who have past puberty before transitioning in elite women’s competitions.

It means that most transgender athletes won’t be able to compete in women’s aquatics events if they have experienced “male puberty.”

The new policy takes effect today and would require transgender swimmers to have completed their transition by 12 years-old in order to compete in the women’s division.

Also, an “open” category was established for athletes in some events. The policy passed with 71-percent majority of  The Fédération Internationale de Natation, founded in 1908.

The decision followed a report from a Fina scientific panel that found trans women retained a significant advantage over cisgender female swimmers even after reducing their testosterone levels through medication.

Fina is the governing body for aquatics worldwide.  Fina’s five discipline Swimming, Open Water Swimming, Diving, Water Polo and Synchronised Swimming  are all included in the Olympics.