New, noninvasive blood tests are being developed for expectant mothers to find out if their babies have genetic conditions such as Down syndrome, without the risks of tests available now. Pregnant women often opt for a prenatal test called amniocentesis that requires a needle to be inserted through the walls of the abdomen and uterus to draw a sample of the fluid surrounding the fetus. The test is uncomfortable and carries a small risk of miscarriage, as does another invasive test for genetic disorders called chorionic villus sampling, or CVS, that samples tissue from the placenta. Now, scientists say new tests of fetal DNA sampled from a mother's blood can be used to screen for Down syndrome. The new blood tests could be performed as early as nine weeks into a pregnancy?earlier than amniocentesis?and may be available as soon as the end of this year. And with the price of gene sequencing and other advanced technology continuing to drop, researchers anticipate noninvasive tests can also be used to detect other inherited diseases such as cystic fibrosis or sickle-cell anemia.
