Testing for potential genetic problems typically requires piercing the
abdomen and amniotic sac to collect a tissue sample from the fetus.
While the risks of this procedure are minimal, there are risks
none-the-less. Researchers in China have found traces of fetal DNA in
maternal blood that may provide an alternative for invasive prenatal testing.

The new findings allow doctors to take a small sample of blood from the pregnant woman and test for a variety of genetic disorders or chromosome disorders. There is no specific list of genetic disorders revealed by the maternal blood test, though in one case a fetus was found to be a carrier of a rare form of anemia. Further research and study is needed before the blood test will be approved for use in obstetrical and hospital situations.

Source: News Release. Science Translational Medicine. 8 December, 2010.