The official policy is contestants are discouraged but no restrictions are placed
There are some interesting answers here
https://www.quora.com/Do-pageant-contests-ban-women-with-plastic-surgery
"For the pageant that President Trump owned they were challenged after denying a transgender woman as a contestant. Answer media hoopla the trans contestant was allowed to compete. Clearly, if contestant is allowed to compete in this particular pageant with hormonal and surgical alterations 2 appear feminine then it would be a bit ludicrous to expect female contestants not to go under the knife. After all, that trans contestant was afforded the opportunity to create as perfect a facsimile for the judges to admire as the doctor had skill and of course the pocketbook had notes. This is fairly hard to compete against……just the facts…you judge the merit"
( I am copy+ pasting from quora, if anybody disagrees take it up with them)
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