How accurate is the baby's weight in an ultrasound??

gobbo1985

So I had an ultrasound at 35 weeks at they said the baby was around 5lbs and then I had one today at 39w 4days and the said the baby was 8.5lbs!! First they said it was a small/average baby and now it's a big baby.

I'm hoping this baby is late, and I'm wondering was the ultrasound correct for you on the baby's weight?

mcgeeva

My doctor said when they did my ultra sound last week the weight could be off up or down a pound. All a guess is how I see it

mcgeeva

Sorry double posted by accident

Rrrrrachel

They can be wildly inaccurate. I had one at 40 weeks that said not to expect a baby under 8 pounds. Baby showed up at 41+2 7 pounds 11 ounces.

Tantan2779

Both times they were off by a pound - baby weighed less than they predicted.

thebretanafam

I was told that my daughter was measuring at 7 lbs. at the absolute most, and this was the day I went into labor. She ended up being 8 lbs. 9 oz., so I don't have very much faith in their accuracy.

pigtails1031777

They thought my 34 weeker would be 4lbs. She was 5.10

cMichelle0423

Ultrasounds are notoriously wrong at estimating baby's weight. They can be off up to 2 or 3 lbs either way. I was told at 40 weeks that my son would most likely not make it past 6 lbs, then 4 days later he was born weighing 7 lbs 4 oz.

karich

Not very, I don't think.

At 36 weeks, my baby was estimated at 4lbs, 11oz. He was placed in the 4th percentile and I started being worked up for IUGR.
Had another ultrasound a week later with MFM who stated she had "no idea" where the last measurement came from, because he was then measured at 6lbs 5oz.
Poof! No more IUGR.

We'll see where he's at when born.

ufsandra85

today i was 37 weeks and they said he was 7 lbs 10 oz but there is a 1 pound margin of error. My sister was told her baby was about 7.5-8 pounds and he was 10 lbs 13.5 oz

kat8805

After my last u/s with my first, they predicted she would be an 8lb baby full term. She was delivered at 38w2d weighing in at 8lbs 1oz. I'd say its about as accurate as a weather forecast.

RebeccaY1

I've heard that ultrasounds aren't a very accurate way to measure the weight of the baby.  It can be off by several pounds. 

Helenahhandbasket

DD was estimated at 7 lbs and was 6 14 at birth-- so for me it was pretty close.  I also have a girlfriend that gave birth to a 9 lb, 15 oz baby boy -- and his estimated weight was 10 5.