Fig. 1: Overview of study design and offer.

Offer (box), study design (longitudinal study), and number of couples through the study flow. The measurements points are T0, T1, T2, and T3. Three subgroups can be distinguished: test offer decliners (participants who did not attend GP counseling and therefore did not undergo expanded carrier screening [ECS]; 60 couples), test decliners (participants who attended GP counseling, i.e., initially accepted the offer, but declined ECS after GP counseling; 13 couples), and test acceptors (individuals who attended GP counseling and proceeded with testing; 117 couples).