New research from Columbia University Medical Center gives genetic testing yet another push toward mainstream use--this time for prenatal care. Scientists there concluded that a microarray diagnostic analysis to screen a fetus' DNA for possible genetic defects was much more comprehensive than the current standard--analyzing a fetus's chromosomes through a visual analysis in a process known as karyotyping. In other words, they caught far more abnormalities that couldn't be seen with karyotyping. Both processes require amniocentesis, an invasive procedure where clinicians take fetal cell samples from amniotic fluid. Researchers pursued their test over four years--a prospective, blinded trial looking at 4,400 patients at 29 centers around the country. Women who took part in the study were older and their fetuses had been show to have potential problems. Release