Hi there guys! I think I found something; but it was never officially stated.
I had a Japanese friend who knew everything about Frieza. She told me once that: "In the beginning, the creator of Dragon Ball Z wanted to make Frieza a girl. Unfortunately he changed it, because he didn't want Goku to hit a girl."
She also pointed out that that's why Frieza (today) has girly-lips, feminine voice, a fine sillouhette etc.
Oh, how unfortunate! I would say.
Now, what do you think? I want to hear your part of the story too.