Effectiveness of preconceptional and prenatal cystic fibrosis carrier screening: a systematic review

Background: genetic testing for cystic fibrosis (CF) has been offered to people with higher risk of being carrier.Objectives: to assess the effectiveness of population-based CF carrier screening for adults of reproductive age and its optimal organizational features.Design: systematic review.Setting and participants: MedLine, Embase, Cochrane Lib- rary, CINAHL and LILACS (1990-2022) were searched to re- trieve primary and secondary studies on adults (16 years and older), with no clinical indication or genetic risk, eligible for genetic testing for CF carrier status.Main outcomes measures: attitude to screening, uptake of screening offered, informed reproductive choices.Results: a total of 3,326 records were screened and 292 po- tentially eligible full-text publications assessed. The review included 71 publications, corresponding to 3 reviews, 40 co- hort studies (11 comparative, 29 single-arm), and 6 model studies, published between 1992 and 2021 (median 1998). Only one study compared screening or no screening. This study suggested an association between carrier screening and a lower incidence of CF. Comparative studies examined different approaches for invitation and testing, i.e., settings, target population (individuals/couples, prenatal/preconcep- tional), how invitations are organized (primary care/maternal hospitals), and format and content of the pre-test informa- tion. However, no firm conclusions can be drawn on the im- pact of these features on informed reproductive choices, up- take, and attitude, because of the limitations of the evidence collected.Conclusions: the broad heterogeneity of the studies, meth- odological weaknesses, and the limited transferability of the results mean there is still uncertainty about the effect- iveness of preconceptional and prenatal CF carrier screen- ing in the general population.