Full title: Latest scientific 'game-changer' in abortion debate, out this week, will send ended pregnancies soaring but prevent heartache, suffering Raising the prospect of a world without birth defects, a Stanford-created blood test that can detect Down syndrome and two other major genetic defects very early in a woman's pregnancy will be available this week. The simple blood test spares women the risk and heartache of later and more invasive tests like amniocentesis. But it has startling social implications — heralding a not-distant future when many fetal traits, from deadly disease to hair color, are known promptly after conception when...