I haven't had my baby yet but - when i had my growth scan at 36 weeks so they could see if the baby was big or it was water they measured its abdominal circumfrance at 39 weeks which matched up with the measurments of my belly 39cm, a weight of about 7.4 pounds at 36 week lol....
so baby is above the higher limit on the scans and measurments, then today at 38+ 5 im measuring 41 week.
However they have told me not to worry as im big so should have a bigger baby, and my body is designed for my baby. The only difference is they are not going to let me go overdue as much as they normally would incase the baby puts on too much weight. So even if measurments and scans show big it may not really matter in the long run -- my consultant says she thinks the charts are out of date anyway x