I'm so sorry that your sister is upset. It's a frightening time around the NT scan time. At our age (I'm 42 was pregnant with DS at 40) they always suggest an amnio. At 40 1:300 is an excellent result, excellent! I think at 40 years old they say to expect numbers of 1:100. As you can see from my signature I have been pregnant before DS was born. With my 2nd angel I had a nuchal scan and all the stress that it caused me was enought to not have the nuchal scan again when I got pregnant with DS. As someone in their 40's it's pretty much all doom and gloom in the numbers stakes. I went straight away to have a CVS procedure - similar to amnio but you can have the test sooner and they take a sample of your placenta and not the amniotic fluid. Anyway........................everyone is different. You can have the best NT results and still have a baby with a disability. It all comes down to what your sister feels comfortable with. She may want the amnio for peace of mind. If not then I would say congratulations 1:300 is an awesome number. Hope the rest of her pregnancy is enjoyable for her.