Yvonne,
That's not true. Blood test alone (even plus the scanning, ie, OSCAR test) can NEVER confirm the results. It's only calculating the risk, doesn't matter how experience the gynae is. This is what I understand about the test scientifically. Unless what your gynae meant by the blood test is that some genetic testing has been done. Though in your sister case, the thickness of the neck added an increased risk. But if it's for me, I wouldn't have the heart to terminate a life without doing the definite confirmation test, ie, amniocetesis.