There is no way to prevent cystic fibrosis. Screening those with a family history of the disease may detect the cystic fibrosis gene in 60 - 90% of carriers, depending on the test used.
Flume PA, Mogayzel PJ Jr, Robinson KA, Rosenblatt RL, Quittell L, Marshall BC; Clinical Practice Guidelines for Pulmonary Therapies Committee; Cystic Fibrosis Foundation Pulmonary Therapies Committee. Cystic fibrosis pulmonary guidelines: pulmonary complications: hemoptysis and pneumothorax. Am J Respir Crit Care Med. 2010 Aug 1;182(3):298-306.
Farrell PM, Rosenstein BJ, White TB, et al. Guidelines for diagnosis of cystic fibrosis in newborns through older adults: Cystic fibrosis consensus report. Journal of Pediatrics. Aug 2008;153(2).
Stallings VA, Stark LF, Robinson KA, Feranchak AP, Quinton H. Evidence-based practice recommendations for nutrition-related management of children and adults with cystic fibrosis and pancreatic insufficiency: Results of a systematic review. Journal of the American Dietetic Association. May 2008;108(5).
Mogayzel PJ Jr, Flume PA. Update in cystic fibrosis 2009. Am J Respir Crit Care Med. 2010 Mar 15;181(6):539-44.
Borowitz D, Robinson KA, Rosenfeld M, et al. Cystic Fibrosis Foundation evidence-based guidelines for management of infants with cystic fibrosis. J Pediatr. 2009 Dec;155(6 Suppl):S73-93.