I had a soft marker for downs with my baby (due 25th sept) having a "slightly" enlarged left ventricle. This was discovered at my 20wk scan, I then got referred for another scan which showed everything to be fine...I refused any more scans after that, I'm going to love my baby no matter what she's like...and not all ultrasounds are 100% accurate! I can understand your worry & stress though *hugs*