Way inaccurate in my case - had a scan at 32wks and was told she was already over 3kg, to expect a big bubba as they can put on 250g a week in the last few weeks

DD was born at close to 40wks and she was only 3.7kg.

Putting on less than 700g in 8wks is highly unlikely... considering all they do in the last few weeks is gain weight, so it was very inaccurate.