there was a really good show on channel 9 last sunday morning (13/4/08) - although it could have been the sunday before but I'm pretty sure it was only last weekend about nuchal tranlucency's questioning the accuracy of them. they have found that using different frequencies can change a woman's results from being low risk to high risk or visa versa. it was very controversial and well worth trying to get a copy of. NTs can be wrong and I work in a child care centre and I have heard SO MANY stories of them being wrong (both ways). They also covered in the show people who had had amnios that resulted in the amniotic fluid leaking, etc It was very sad for those poor women.