Yes my DS had a dilated kidney, which was found at the 20 week scan. I had another scan at 35 weeks and it was still there, another scan after birth and it had decreased compared to the 35 week one. The Paed referred us to the children's hospital for monitoring, and we have to keep an eye out for an indicators of a kidney infection, so far (8 months on) he has been absolutely fine.
Downs has never been mentioned to us. I wouldn't google too much it can scare you and who knows if what comes up is true.