Editor—Couples in which both partners are carriers for a particular autosomal recessive disease, such as cystic fibrosis, Tay-Sachs disease, or thalassaemia, have a 1 in 4 risk for each child to have this disorder. Population carrier screening programmes aimed at the identification of carrier couples make it possible to inform these couples about their risk and about the reproductive options that are available. Before beginning any genetic screening programme, it is important to assess community interest in screening.1

It is well known that the way in which carrier screening is offered and the timing, for example, during or outside pregnancy, determine participation in screening and the reasons for participation. Screening offered face to face with the possibility of immediate testing gives high uptake rates, whereas offers made by mailed invitation or poster announcements attract little interest.2-6

Most of the data on motives for participation have been obtained from programmes offering carrier screening during pregnancy.7-15 In these studies, a high interest in screening was reported, although it has been argued that testing during pregnancy is often accepted just because it is offered.16The decision to participate was mostly made by women, who were often initially tested without discussing it with their partner. Anxiety has been reported among those who are tested positive, while waiting for their partner's results.10 17 18 It can also cause distress when the partner is not available or does not want to be tested.19 Furthermore, prenatal screening leaves limited reproductive options for a carrier couple and might impose time constraints when decisions about a prenatal diagnosis have to be made.20 Offering carrier screening outside pregnancy shows low participation rates when no pregnancy is planned, but interest is higher when there are plans for having children (preconceptional).4 7 …