How accurate are u/s?

I was just wondering how often they are right..The reason why is because on Jan. 8th (26.1wk) I had an u/s and the weights were 2lb 1 oz and 2lb 7oz..Now three weeks later at 28.1 weeks the weights are 3lb 7oz & 3lb 13oz...Now that is 1lb and 6oz a peice in 3 WEEKS...So does that sound about right..TO me that seems like alot of weight gain for the babies in just 3 weeks..I still have 9 weeks to go...

 

I was just wondering how often they are right..The reason why is because on Jan. 8th (26.1wk) I had an u/s and the weights were 2lb 1 oz and 2lb 7oz..Now three weeks later at 28.1 weeks the weights are 3lb 7oz & 3lb 13oz...Now that is 1lb and 6oz a peice in 3 WEEKS...So does that sound about right..TO me that seems like alot of weight gain for the babies in just 3 weeks..I still have 9 weeks to go...

 

Generally there is about a +/- 10% error in U/S. You are at a point that they grow quite quickly.

 

My U/S was a few oz off on both babies, it was very accurate!

Grow babies grow!! Keep up the good work!!

 

I was told they can be up to a pound off, but ours were only ounces off

 

My doctor just told me yesterday that they can be about 8% off usually.

 

My u/s said it can be off by up to 13 ounces, either way. My u/s tech said the further along you get, the further off the numbers can be.
Helen

 

Mine were off by a about a lb. But then again I went to the peri and a few days later with the ob and they took measurements. 2 different u/s techs, 2 different results for weight. Depends on where the stop the little cursor. A mm or so can make a difference. But they give a good ballpark.

 

Mine were real accurate, but I think you are really at the stage where they are rapidly gaining weight and they will slow down a little soon. But growing is good! Keep up the great work!

 

Mine were accurate within a few ounces, I delivered one week after my last estimate so they were pretty accurate. In the later stages of pregnancy they can definitely be as much as a pound off.