From an ethical point of view, there is an important distinction between two types of prenatal screening. The first of these targets maternal or foetal conditions (e.g., infectious diseases, blood group sensitization) where early detection allows for interventions that improve the chances of a healthy pregnancy outcome. The second screens for foetal conditions such as Down syndrome, where a timely diagnosis in most cases only allows for a choice between preparation for a child with special needs or termination of the pregnancy. Whereas the former makes an easy fit with the prevention aim of most other population screening programmes, the latter does not. In order to steer clear from a possible eugenic reading of its aim, a wide international consensus has emerged for the view that prenatal screening of this type should have the atypical aim of helping women (couples) to make autonomous reproductive choices, rather than reducing the birth prevalence of the relevant disorders. However, keeping these types of prenatal screening apart may become increasingly difficult given the development of tests, such as the Non-Invasive Prenatal Test, which cannot only be used for both types of screening but may also lead to interconnected findings on both sides of the divide. This makes it an urgent question: What the aim or aims of this new hybrid screening should be? As neither 'prevention' nor 'autonomy' will do, we argue for a normative framework that gives both aims their due, while recognizing the tensions between them.