How Accurate are Sono Weight Estimates?

[momgoddess]

They are VERY inaccurate this late in pregnancy. I think they are more accurate early in pregnancy, but they are usually off by 2 lbs or so either direction in late pregnancy.

[hbee]

I had one at 34 weeks 6 days and it was 4 lb 7 oz. She was born 5 days later at 5 lb. Pretty close!

[g-offsmommy]

Mine was off by 2 lbs! I was told he was over 9.5 lbs, he was only 7lbs 4 oz.

[Christina]

With my first baby they told me a week before I delivered to be prepared for a big baby, like 9 1/2lbs at least. They kept insisting after an u/s that it was definitely a big baby.

DD was born a week later and boy were they surprised at her tiny 6lbs 6oz. They were off by 3lbs with her.

[Urchin]

My DD was diagnosed with IUGR. At 36 weeks she was measuring 4lbs 9oz and then at 38weeks, the same. Which TOTALLY freaked me out. I was induced at 38w4d and she was 5lb 5oz....so the u/s was off a bit...lol

[andyoly82]

The high risk office seems to be really on point here with our measurements. The told me DS was about 6lbs 4oz. He was born 12 hours later at 6lbs 4oz. Same dr was correct with both my friends babies as well.

[tazzae]

I had an ultrasound 12 hours before dd was born. They were very concerned--based on u/s measurement--that she was under 5lbs. She weighed 6 lbs at birth. So, under estimate by over a lb.

[ktmelody]

I have had 2 different experiences.

With my 5th they had me being monitored for IUGR. 24 hours before her birth the peri measured her at 4 pounds 1 ounce. She was born the next evening and weighed 6 pounds 1 ounce at 34w5d. They were way off and she didnt meet the criteria for IUGR.

My 7th was born 3 months ago. My ob thought she was tiny and had me go for an ultrasound and she was measuring way ahead. 5.5 pounds at 32 weeks! 12 hours before her birth my OB measured her and guessed 8pounds13ounces. She was 8pounds14 ounces. So he was off an ounce. . i was 39 weeks.

It is hit or miss. 2 pounds either direction.

My friend delivered 2 weeks ago. At 35 weeks they told her 7.5 and 4 weeks later her baby was born and was 6.10. Waaayyy off there!!

[slimy72]

Ultrasound thursday afternoon showed my boy was 11lbs 2 oz. He was born Noon on Friday at 11lbs 7oz. So they were 5 oz off. But he was big either way.

[mariamommy]

My ultrasound weight estimates right around my due date have actually been with in a pound. I had large babies.

Prediction with my first: 9.5 lbs, actual: 10 lbs 4.6 oz
Prediction with my second: 8.9 lbs, actual: 9 lbs 13 oz
Prediction with my third: 9.5 lbs, actual: 10 lbs 3 oz.