Growth Scan at 34 weeks. Anyone's get the size about right?

[MommyD]

ds2 growth scan at 34 weeks indicated baby's size was already 6lb. He was born three weeks later at 6lb.
Just had 34 week growth scan for baby number 3 and it is suggesting baby is almost 7lbs already!! Are these scans at all accurate?
Also on the scan notes it says that the umbilical artery PI is only on the 5th centile. Anyone know what this is - blood flow? Wish I'd seen it earlier and asked..... whatever it is, it seems a bit low!!

Had growth scan at 34 weeks with my dd now 10, it was almost spot on, same again 7 1/2 yrs later with dt's, they were also spot on. However I know friends who have had scans that have been miles out..... who knows?

Message withdrawn