I agree with everyone else it is very strange that you were referred for that test before the 11 week blood and 12 week Nuchal fold scan.

I am 36 and jusy had my bloods and scan done. I came in at about 1:450 and my ultrasound guy and midwife said they don't even suggest referral for women for a CVS or amnio unless their result is greater than 1:300.

Good on you for looking into it and questioning things - too many of us just accept that a doctors word is like the word of the Almighty.