Abstract
Down syndrome (DS), often caused by trisomy 21, is the most common form of intellectual disability among newborn infants worldwide 1 . Differences in annual live births have been observed per continent: around 17,000 annual live births of children with DS have been estimated in Europe 2 , around 5,100 annual live births of children with DS have been estimated in the US3, and around 300 annual live births of children with DS have been estimated in Australia and New Zealand 4 . The presence of prenatal screening and elective terminations has negatively influenced the live birth rates of children with DS.
The availability and accessibility of prenatal testing (like non-invasive prenatal testing) and genetic counselling certainly have a current and future impact on the number of live births with DS 5 . In addition, there is a risk of the routinization of prenatal screening, where parents are no longer facilitated to make informed decisions based on their own moral and practical considerations, but family members, relatives, and friends alike, implicitly or explicitly expect that parents will choose prenatal screening, diagnostic testing, and, perhaps the termination of pregnancy 6,7 . Such potential societal pressure may increase the effect of the availability of prenatal screening on the live birth rate of children with DS. Other factors - such as religious beliefs, economics, the complexity of society, changing maternal ages, cultural beliefs, and social norms - likely play additional roles. The anticipated quality of life for a person with DS might also be an essential consideration in the decision-making for some expectant parents 6 .