What froggy said is right. The research shows that CF does not cause damage perse, but it does create thick mucus secretions in the body-everywhere in the body. So that would include the cervix as well. some women have had success with taking a form of robitussin. You have to be careful though, you don't want the kind that supresses a cough as that can lead to more mucus secretions in someone with CF and further complications (although sometimes given on a one or two time basis to allow someone to get some much needed rest or something-you would be using it more often than just once or twice for fertility purposes). You want to get the kind that thins secretions. I believe it's called guiafesn (that is not spelled right-someone help me out!!!!). Have you seen hollycatheryn's website on fertility? If not, the link is floating around here somewhere-she is really really good with the female aspects of this, she may have more information than what I have posted. Let me know if you haven't seen here site and I'll loook for it. It's on my fav's at home but I just got to work.....
Julie