In this week’s Medical Discovery News by UTMB’s David Niesel and Norbert Herzog: Until recently, Down syndrome could only be confirmed by invasive tests that collect cells from the amniotic fluid surrounding the fetus, the placenta or the fetus itself. These tests can be risky, with a 1 percent chance of miscarriage. However, a new, noninvasive screening test called circulating cell-free fetal DNA analysis may reduce the need for invasive prenatal tests. Circulating cell-free DNA from the fetus makes up 3 to 13 percent of the DNA fragments circulating in the mother’s bloodstream during pregnancy. The column also appears in the Galveston Daily News.