Countrywide Variables Associated With the Reduction of Fetuses With Down Syndrome.

Abstract

In this study, we sought to analyze the associations of global macroeconomic policy decisions on live births with Down syndrome (DS). As countries made prenatal screening more available and financially covered by their governments, we modeled the impact on the "reduction percentage" for DS-that is, the percentage of fetuses with DS that were not born as a consequence of selective terminations. The log-odds of the reduction in live births of children with DS (due to selective abortion) were estimated using maternal age-based prevalence models and actual birth data. These log-odds were then predicted using independent variables, including the availability and reimbursement of prenatal screening, maternal age, Gross National Income per capita, and country-specific effects. Data were analyzed using least squares regression with robust standard errors and model validation. When there is a full change from "no availability of screening" to "serum screening available and reimbursed," we observed a large effect on the reduction percentage (OR = 3.24, p = 0.0001). If a country, whose baseline reduction percentage was 5%, 25%, or 50%, were to make this policy switch, then the reduction would be expected to increase to about 15%, 52%, and 76%, respectively, when all other variables are held constant. Increases in maternal age and Gross National Income also were associated with increased reduction percentages. If a country were to expand the availability or reimbursement of prenatal screening for DS, while all other factors are constant, that country should also expect to have fewer live births with DS as a consequence.