It *could* be accurate with just one U/S to determine it, but off too. I have weight checks on Bodie every 3 weeks (so my next is Monday) and my U/S guy said the really only way to be accurate is if you're having them regularly to determine how much they've grown too. So 2.5 weeks ago he was 4lbs 13 ozs, they are anticipating he'll be no bigger than about 7lbs 5ozs when he's born in 13 days. We'll see tho, he feels smaller than my last based on how they sit in there and she was 7lbs 3ozs.
Tenk ~ happily married with lots of kids