Baby's weight by ultrasound how accurate?

Question

How accurate are ultrasounds in determining baby's weight

I am 28 1/2 weeks i was just curious because they are going to do a growth scan tomorrow

Answer 1

If you have the growth scan at the same facility each time, they chart the growth on a curve on the software, this is pretty accurate. If you have the study done at a level 2 facility it shouldn't be off by more than a half a pound.

Answer 2

Congratulations on your pregnancy,

It is very hard to tell how heavy the baby really is just think the baby is floating in a lot of liquid so bub is weightless, when they say bub will be a certain weight don't take it as that's how big bub really is, the only way you will really know is after bub is born and weighed.

My experience with this has been very off, I was told throughout my last stages of pregnancy that I would be lucky to have a 5lb baby as that's what they thought during the ultrasounds and I was only tiny, my first born was 6lb 12oz.
My second pregnancy they again had me stressing that my baby would be tiny and only 6 days before she was born I was told she would be about 5lb, she was a nice healthy 6lb 5.5oz.

It can be alittle stressful been told your going to have either this tiny little baby or a huge baby but when they are born they are a nice healthy size. Please only take this as a estI'mate not that is how big bub will be, Good luck and im sure bubba will be perfect.

Answer 3

Mine personally wasn't extremely accurate. They were off by at least .5 of a pound - possibly more. Babies grow so fast though, so it's hard to correctly gauge the weight. You may have an ultrasound a few weeks before you deliver, where they tell you the baby's weight, and the baby may end up being bigger at delivery. It always depends. Congratulations on your upcoming arrival!

Answer 4

I'm 25 weeks pregnant and when I had my ultrasound at 20 weeks, my little boy weighed 14 ounces. Average for 20 weeks is said to be between 10 - 12 ounces. Maybe I'm having a big baby! Sorry I couldn't answer your question.

Answer 5

The older the baby is, the less accurate the measurements can be. at 28 weeks, the baby should be around 2.5 pounds.

Answer 6

Usually within 1/2 pound... They take a measurment of the femur bone length and width and do an extrapolation of weight based on an average weight of a child with those measurments...

The femur is used because it is the largest easiest seen and measured bone..

Answer 7

I'm not sure but at 20 weeks my baby weighed 12 ounces. I am now 23 weeks and curious to how big he is. Sorry I couldn't answer your question but I just wanted to know how far along are you and how much did it say your baby weighed?

Answer 8

its not very accurate i had an ultrasound a week before i had my daughter and they told me she was 5 pounds and wouuld be six at delevery.....i had my daughter the following thursday...7 poundsd 12 ounces...thats nearly 8....

Answer 9

Not at all!

I have heard of babies deliberately puffing out their little bellies at ultrasound time to make themselves appear larger. I've also heard of smaller babies secretly holding rolls of quarters under their tiny arms so as to increase their birth weights. No one likes a happy giggle more than a baby, but they DO take it too far, sometimes!

Answer 10

MY FIVE CHILDREN WERE ALMOST TO A "T" THE WIEGHT THE ULTRASOUND SHOWED.
I HAD BIG BABIES SO I SAW THERE ULTRASOUND WIEGHT ,
THE DAY BEFORE INDUCTION
AND IT WAS ALWAYS RIGHT.