Hi, so, feeling a bit down/ deflated.
The scan showed no serious defects but the dino apparently has a kidney abnormality - hydronephrosis - which is the same that I have.
The thing is, the sonographer seemed a bit crap. He clearly hadn't read my notes, as when I said I had the same, he was quite surprised. He also didn't say anything about prognosis. Now, because I've had this condition for awhile, I know it's often a paediatric condition which can mean surgery in infancy. He obviously didn't really know about that.
He was also crap at explaining - he kept saying "now our cut-off is a 7, and you're an 8". I was like "7 what, is this some type of scale??" By looking at the screen I could see he must mean millimetres (as in, the pelvis of the kidney measured 8mm and should have been under 7) but this wasn't remotely clear from what he actually said.
He also said he wasn't sure if it was a boy or girl - which is fine, I know they can't always tell - but then he started saying he thought it was a boy whose testes hadn't descended properly. He said this was "a bit unusual" but didn't mark it up as an abnormality on the sheet. So I don't know if I'm carrying a boy with a genital defect, or if it's something that will correct itself, or he just didn't know.
Also-also, I am currently 20+4 but whenever he did a measurement it flashed up onscreen as measuring 21w 2d or 3d. So I thought maybe it was quite a big baby, as apparently measuring a week ahead, but he didn't seem to understand what I was asking when I mentioned it. He just said "look around, everyone's different, some people are bigger than others, don't worry about it" 
However, having said all that, the dino is alive, moving, and there are no abnormalities of heart, brain, spine, so afaik it's a totally viable and healthy pg, just with this question mark over the kidneys.
I have to go back at 33w for another scan, so hopefully things will be clearer then. Also seeing the consultant again in 10 days so might ask for some more info.
Sorry to whinge
I know I should just be grateful to have a baby, but I had just hoped to be waved off with a cheery "everything's fine" and it's a bit shit that there might be a problem.