We declined this test with both of our babes.

Basically we decided that if we did come back with a result indicating high risk for downs, we would not be able to risk the pregnancy with an amnio. Especially when we would never have terminated even IF our baby had DS.

This is essentially what your doctor is getting at - the initial ultrasound just identifies your risk factor. To find out definitively whether or not your baby has it involves much more invasive testing. If you would decline that testing down the track, there is little point having an NT scan.

There is also quite a high incidence of mother's being told they are high risk and having amnios on normal pregnancies. This is why this test is said to have a high "false positive" rate.

GL and congratulations btw