Switzerland has more or less the same strict name laws as Germany, and if you want to use a name that does not tell the gender you have to use a second name that does.
However, being born and living in the German-speaking part of Switzerland, I never heard of
Andrea in particular as being such a problem case. In
German Andrea is clearly female, and people from the German-speaking part don't have a problem with its gender.
It might be otherwise in the Italian-speaking part of Switzerland however; I just don't know about the situation there.
Rene www.AboutNames.ch