Antenatal cystic fibrosis carrier screening--whether, when and how?

Population screening for carriers of cystic fibrosis (CF) is now possible. Such screening may have both advantages and disadvantages and hence must be evaluated before it becomes routine practice. As the potential benefits of screening are wide and the drawbacks may include psychological effects, a combination of approaches is needed to assess screening thoroughly instead of only counting numbers of terminations or carrier tests. We describe the issues concerned and our methodology for a rigorous evaluation of population antenatal carrier screening for cystic fibrosis.