I know that athletes doing this have to take hormones for 2 years.  But, as we all know from the TRT debacle in the UFC, hormone and drug tests can be cheated.  Remember when Vitor Belfort came in clearly abusing TRT but no one could prove it? 

What are they gonna do when a transgender athlete is taking incredible hulk levels of testosterone cheating her hormone and drug tests, and comes into womens boxing or something as a clearly roided up man, but no one can prove it?

In MMA/ UFC they had to ban TRT for everyone because they just couldn't , even men with medically low testosterone levels that really needed it (like Bigfoot Silva). That sucked for guys with real medical conditions that weren't abusing it, but it had to be done.

I suspect that women's sports will have to do the same thing when that time comes when a transgender athlete is obviously cheating the hormone tests and everyone knows it but no one can prove it. That will suck for transgender women that legitimately play fairly by the 2 year hormonal transition requirement, but it will have to be done.