Ultrasound baby weight estimate question

rascus15

I just had a two night hospital stay due to bleeding issues. (Placenta Previa)  I was 32 weeks and 1 day when I was admitted.  On that day we had an ultrsound.  The tech told us that the ultrasound machine they were using is the latest and greatest and is very accurate. A few weeks ago we had an ultrasound done at the same hospital and that tech told us the same thing.  They both told us the machine was accurate for the baby's weight, give or take a half pound.  This last scan measured the baby at 5 lbs 2 oz.  All other ultrasounds we have gotten we were told weight was correct within a 2 lb range.  I was just wondering if anyone else has had ultrasound on brand new machines have been told the weight is accurate within a 1/2 lb?  How close was the weight estimate to what LO actually weighed.  All along we have been concerned that the baby would be small due to my fibroid issues.  If they are accurate, it makes me feel a bit better about the situation should I need to deliver early.  The doctor told me, the bigger the baby the better they tend to do if delivered early. 

Edited to clarify 

Geeps2

When I had my final ultrasound I was given the "guesstimate" on the weight at birth being 7lbs +/- 1 lb either way.  My son was born on my due date weighing 8 lbs even.

mwhipple77

@rascus15 - I don't have any experience with your question, but wanted to let you know I hope the remainder of your pregnancy goes well and you don't have any additional hospital stays before your birth.  

MommyAtty

They say 20% off either way is generally within the margin of error. And a whole lot does depend on the tech, even with the most up to date machines.

But take sighs of relief wherever you can get them! My ultrasound last time was pretty darned close to exact. Said the baby would be 6.5 lbs. she was 6 lbs, 3.5 ozs. So off by 4.5 ozs.

rascus15

@mwhipple77 Thank you!  We are doing everything we can to keep baby in as long as possible

Thank you ladies for the input.  I was a little hesitant to take the weight estimate as fact, but even if the baby is a lb less than the estimae that is still the upper end of the averages I have seen for gestational age on line so I wil take what I can get   I appreciate knowing your experiences.

rascus15

I wanted to post  here for any future information surfers.  The u/s over my weekend of hospitalization said 5 lbs 2 oz.  I went into labor on that following Monday night hemmorhaging with a placental abrubtion.  The Tuesday morning u/s showed weight to be 4 lbs 11 oz.  He was born @ 11:59 am that Tuesday morning weighing in @ 4 lbs 6 oz. 

shelley1002

Congrats on the arrival of your little boy.

rascus15

Thank you!

SurpriseAt39

I had biweekly U/S with DS2 from 30 weeks on.
Based on consistent rate of growth (from one U/S to the next) being 1-1.5 lb increase over 2 weeks, and my last U/S being 8 days before birth, the last estimate was only 3 oz off actual size.
He was 9 lbs 2 oz at birth, but they would have estimated 8 lbs 15 oz.

*actually, they never used the word 'estimate'. They said 'baby is...' At each U/S.
I'm in Toronto Canada area, so I'm not sure how equipment here compares to the US. (Or wherever you are)
But I'd say it was spot on for me. They never said it could be off one way or the other.