Okay first let me tell you that I think drs stink!!! Especially when it concerns telling you your baby might have d.s.!!!
When i had my 1st u/s they told me all of Haley's measurements were fine, except for the bright spot in her heart which could mean she has d.s. Well since my dr wouldnt answer any of my questions, and i was of course FREAKING OUT!!!, i didnt quite make it to work the next day. Instead i stayed home and researched allll day. I even called the National Down's Syndrom Congress...among others. What I found is that if all of the babies measurements are fine and the Nuchal fold one was the only one off (according to them...Haleysmum's right about how early they did it on you), but even if the Nuchal fold is still off on your next one...your baby is way more than likely perfectly fine! The femur and humerous (sp?) both measured at normal development growth, right? Hands aren't too squared, feet look good, belly circumference normal? Then don't worry.
I have since also talked to one of my closest friends who is a severely handicapped teacher, i worked as her aide for 3 years several years ago. She reminded me of all the measurement stuff i stated above, stuff that I knew and should have thought of when that da*n dr uttered the d.s. term. But you know how emotions can get in the way.
Bless you and your perfect little baby! (sorry i rambled on...this still pisses me off to no end! hope you can make sense of it)