The following is an excerpt.
Conventional methods for checking a baby’s genome for abnormalities require invasive procedures, such as using a needle to withdraw some amniotic fluid surrounding the fetus or some cells from the placenta, methods that can sometimes cause a miscarriage.
These tests mainly focus on abnormal numbers of certain chromosomes (such as the condition that causes Down syndrome) and are offered only to women with high-risk pregnancies. But much more could be gleaned from the fetal DNA floating in mom’s blood, and some believe that such tests will soon be available to many women.
Read the full article here: A Brave New World of Prenatal DNA Sequencing