June 24: In order to determine if a child has Down syndrome before birth, doctors often perform the invasive procedure called an amniocentesis, which uses a needle to remove a sample of the amniotic fluid surrounding a fetus. It's a dangerous procedure that can result in miscarriage. But doctors in Hong Kong developed an experimental test that can detect Down syndrome from the blood of pregnant women. In small trials, it has been shown to diagnose 90 percent of Down syndrome cases, while also correctly identifying 97 percent of fetuses that do not have the condition. With more testing, doctors are hopeful it will transform prenatal testing for the syndrome.