What do these numbers mean on 12 week scan?

good question I wondered the same!! I just had a look at my 12 week and 20 week scan and i'm guessin most of the numbers r only relevant to the machine being used. Both my pics also have 13.1cm on them! Some of the other info on mine is 1 trim and 2 trim (which trimester),my 12 week has Har. high then the 20 week has Har.med which I've no idea about!!!? Who knows! My baby is due tomorrow,all the best to you x