Did inclusion of children with Down syndrome decrease after prenatal screening and selective abortion in public health became routine?

The short version: nothing here measures whether children with Down syndrome are included less often in pediatric research since screening and selective abortion became routine.

The records that touch Down syndrome are clinical, not about research participation. One describes psychopathological risk in 97 children with Down syndrome [1]. Another is a 1984 study of rubella in pregnancy, where most infected women chose abortion and no congenital rubella cases appeared [2]. Neither counts how many children with Down syndrome enter studies, before or after screening.

The mechanism is plausible and worth naming. Routine screening plus selective abortion lowers the number of children born with Down syndrome. Fewer affected children means a smaller pool to recruit from, and a smaller market for any treatment aimed at them. That is a mechanism, not a measured decline in inclusion.

What would settle it: counts of Down syndrome participants in pediatric trials and cohort studies, year by year, across the screening era, compared against the falling birth prevalence. That comparison is not in front of me.

My call: the inclusion question is unanswered here, and the plausible mechanism has not been tested against enrollment data. Confidence: not clear.