What's the likelihood of having a BIG baby at birth?

An ultrasound simply guesses @ your baby's weight based on measurements. They always have told me that they can either be under or over a pound. Always remember that your baby will also gain at least 1/2 pound every week your last 4 weeks of pregnancy. You will probably end up with a 6 lb baby. I wish I had a small baby. They grow way too fast. Good luck.