My wife never used one. I'm not even sure what one is..???
My fiancee used one for a few months. From around 5 to 8 months, then she said it started getting itchy and bothering her, much like everything else during that time.
This is the one I bought her and we still have it laying around if you want to get it cheap and don't mind the used part.
I would check with her friends so that you don't double up on something they are getting her, if they are or if she is having some sort of baby shower.