Soon, pregnant women may not need to decide if pre-natal genetic testing is worth risking miscarriage: a new technique, published in Proceedings of the National Academy of Sciences , involves using bits of fetal DNA in the mother's blood to count chromosomes. Errors in chromosome number are an indication of physical and mental development problems. Only a sample of the mother's blood is needed, while current prenatal gene tests, such as amniocentesis, require inserting a needle into the uterus and carry a .5 percent risk of miscarriage. In addition to increased safety, doctors hope that the new test — which could be available in clinics in the next 2-3 years — will spot genetic problems such as Down Syndrome much earlier. [EurekAlert ]