I agree with the advice you were already given. Going into my 35th week they told me my baby was predicted to be "well over" 10lbs at birth, and they asked if I wanted an elective c-section because I qualified. I'm not gonna lie...I considered it. But I decided to go for it and I could always have a c-section if something went wrong.....
Well, I had my vaginal delivery...3 solid pushes over 6 minutes of pushing, less than 4 hours of labor total..and out popped my boy: all 7lbs 10oz of him. So they were TOTALLY off...I had a high fluid volume and that distorted their measurements. I'm glad I stuck to my guns! my recovery from his delivery was INSTANT. I was up, sitting cross-legged within half an hour and walking and normal with almost no pain right away...so....I'd say, let baby come when he's ready AND...go for a vaginal. you can always get a c if an emergency pops up....but the predictions about size are almost always off :-).
Macrosomia = big baby
Macrosomia is a baby who is over 9 lbs 13 ounces
So your baby can be almost 10 lbs and these professionals still state that it is NOT a reason to induce or for a cesarean. Remember you can refuse and don't feel bullied into anything. I recommend the book Pushed by Jennifer Block. If you'd like some other references on birth books I'll gladly give them to you. You may have to PM me as I might miss this post if you respond here.
They cannot properly and appropriately guess fetal weight via sonogram due to the fluid surrounding baby. It can be off by as much as 2 lbs! Your little one may actually be 3 lbs. If they want to induce you due to macrosomia I just want you to know that ACOG (American College of Obstetricians and Gynecologists) as well as WHO (world Health Organization) and other medical professionals agree that a diagnosis of "large baby" is NOT a medical reason to induce or to perform a cesarean. Let baby come when he is ready (provided it is over 38 weeks!).
I wouldn't rely on ultrasounds to guess weight. Some ladies on here will tell you they were estimated to have a 9 lb baby and it only came out at 7 lbs or in my case my baby was measuring a month small but was almost 7 lbs when born at 39 weeks. She was only supposed to be around 5 lbs. Also when I got my ultrasound for weight they had 3 different techs do it and all were within a pound off from one another.