How accurate are growth scans?

Question

Currently 34w4d… most recent growth scan is putting baby in 90th percentile. Estimated at 5lbs12 currently

They are concerned I have gestational diabetes, despite 2 GTT done and results normal through pregnancy. Now wanna monitor sugars and schedule a 3rd growth scan.

Just wondering for those who have had growth scans, how accurate have they seemed to have been??

Answer

As per my doctor, the scan can be off up to 20% in either direction. 
Two weeks prior to birth they approximated my son being 5lbs 12oz. He was born at 7lbs 1oz

Answer

My daughter was estimated to be over 8 pounds and she was only 6 pounds when she was born

Answer

They scans can be off a pound or two one way or the other. My daughter measured right on schedule my entire pregnancy but weight was off by a pound at birth. They said she would be around 7 pounds and she was 8 pounds. My son was measuring right on track until 20 weeks and then he started measuring a week ahead with his abdomin measuring bigger than that. His head measured 73rd and abdomin 98th with weight coming in at 9.5 pounds. We opted for a c-section because we were afraid he'd be even bigger than what the scan said. Thankfully we did because he was bigger than measurements shown

Answer

My son was estimated to be around 6 pounds 5 oz at 36 weeks. He was born at 38 weeks & 4 days at 6 pounds 10 oz.

Answer

They can be off in either direction

How accurate are growth scans?

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