Hi Krystle, my doc told it is purely a scan to determine if the baby will be a downs one. But as someone else said, the scan is not 100% accurate. It's measured on the baby's neck or something like that. If the measurements are in the downs area, then that's when they ask if you want the needle into the placenta which can cause miscarriage.
I could not go to the hospital and get it done for free, as I am not over 30, so I have to go to a private clinic and is going to cost me $390!! Which I will get probably half back from MC. I don't particually want to go for the scan, but my fiance does. My appt is 21st Oct, so I am feeling a little anxious about it.