Complete prevention would only be possible if universal carrier screening were possible and acceptable to the public. Screening would have to be genetic, but there would always be the likelihood of missing rare variants. Experience is that in any case, take-up of carrier screening offered in an antenatal clinic is low, in the absence of a family history. Newborn screening should facilitate a reduction in prevalence. In the first instance, there is an opportunity for the couple to test future pregnancies for CF; and secondly, genetic testing (targeted at the genes found in the affected baby) can uncover other at-risk couples in the extended family, also enabling antenatal diagnosis.