In general I think most doctors like your PFTs at at lest 70%. BUT much depends on your overall compliance, bacteria cultured, support system, responses to meds, CFRD etc. One of the problems is that pregnancy can take its toll even on people with no CF so its hard to say how each CFer will respond. I had a fabulous pregnancy with my hemoptysis only rearing its head in my 8th month. Some CFers are in the hospital and having difficulties from day one. This is one of the big arguments when it comes to CFers getting pregnant.