World Athletics on Saturday said it is consulting with member federations on a proposal that would impose more stringent testosterone limits on transgender women athletes competing in women’s track and field events.

The governing body’s proposal stops short of calling for an outright ban on trans athletes and said it arrived at its “preferred option” after reviewing a number of new and existing scientific studies and observations from the field.

World Athletics stressed that no final decision has been made on the matter after the U.K.’s Telegraph newspaper reported on the discussions.

“Putting forward a preferred option is the best way to gather constructive feedback, but this does not mean this is the option that will be presented to Council or indeed adopted,” World Athletics said in a statement.

The option being discussed would cap the maximum amount of plasma testosterone for transgender women and those with differences in sex development (DSD) at 2.5 nanomoles per liter — half of the current limit of 5 nanomoles.

It would also double the amount of time the athlete would need to remain below that level to two years.

A final decision over the proposal will be made by the council in March, the Telegraph reported.

In June, World Athletics and soccer’s governing body FIFA both said they were reviewing their transgender eligibility policies after swimming’s world governing body FINA passed rules banning transgender participation in women’s events.

World Athletics president Sebastian Coe at the time praised FINA’s decision, which has been criticized by transgender rights supporters.

Advocates for transgender inclusion say that there are relatively few trans women athletes and that not enough studies have been done on the impact of transition on physical performance.

Opponents say testosterone suppression does not fully remove the advantages for someone assigned male at birth who has gone through puberty prior to transitioning.