Pregnancy: How accurate are ultrasound measurements?

[HM]

I didn't have ultrasounds with either of my children. The doctors (two different practices) didn't do them unless there was thought to be a problem with the baby. I guess not having one kept me from this worry (as well as others). Sorry it threw you for a loop OP.

 

[scrapquitler]

Had a 28 week ultrasound the other day & the tech took some measurements and said my baby is in the 84th percentile for her height!!! (weight was in the average range) This threw me for a loop a bit. My DH is tall & I am very short. Our current DD is totally average in height.

Just wondering if any of you received ultrasound measurements when you were pregnant and the measure ended up to be totally inaccurate?

I also wonder, will she remain in the 84th percentile through the rest of my pregnancy or can that still fluctuate and change?

size estimates via ultrasound are not accurate. Two days before my DD was born, they did an ultrasound and told me she would be 'at least 10 lbs'. She was 8lb 13 oz.

As far as the 84th percentile....your DH is very tall, maybe your daughter will be, too. But 84th percentile is not freakishly large.

 

[TLSnell1981]

Ultrasounds weren't the norm when I had my babies. Size and weight was estimated by the hands of experienced midwives. I find it interesting...they were within a 1/4 pound on each pregnancy

 

[BadgerGirl84]

I never got weight or height measurement estimates with my DD, but if I did, I wouldn't take them seriously. There are so many stories of women being told they have humongousn babies and need to be induced early or else the baby will be 10+ lbs...and then the baby is a normal size. Or the other way around!

Like others have said, 84th percentile is not freakishly tall--just normal tall, so that wouldn't be a blip on my radar either.

 

[Stephaniesue]

I have not read all of the responses here.

But, I have some info . I was told by my ultrasound tech during my pregnancy with my son that the further along you are the more distorted the measurements can be. They can vary by a pound either way.

 

[mnrose]

I had twins, which may have made the us measurements harder. But, just days before they were born, they said my DD would be close to 8 pounds, and my son would be lucky to be 3 pounds. In fact, he weighed 4 pounds 3 ounces and my D weighed 5 pounds, 14 ounces.

It wasn't terribly accurate....although they did get the sexes right, and they did accurately determine that my D was bigger than my S.

BTW, that difference completely disappeared by the time they were 3 months old, and my son (who was so tiny at birth) is now a strapping 5'10" tall at 14 years old.

 

[msjprincess]

Mine weren't very accurate. I had a sonogram during the day and was told my son was 9lbs. That night I gave birth to a 7lb 110z baby.

 

[ellone]

I never got weight or height measurement estimates with my DD, but if I did, I wouldn't take them seriously. There are so many stories of women being told they have humongousn babies and need to be induced early or else the baby will be 10+ lbs...and then the baby is a normal size. Or the other way around!

Like others have said, 84th percentile is not freakishly tall--just normal tall, so that wouldn't be a blip on my radar either.

I never got height on my ultrasounds, but I did get weights because both times I delivered at 41 weeks and at 40 weeks I had to go to the doctor every other day. Both times they thought my kids would be over 9 lbs. Both times they were under 8 pounds. Actually pretty average for a babies delivered full term (I think).

And I agree 84 percentile isn't freakishly tall. My two girls pretty much stay in 97-99 percentile and that IS tall.

 

[aristocatz]

I'm not particularly worried about it, I was just surprised & wondering what other peoples experiences were with the accuracy of u/s measurements.

 

[pigletgirl]

Mine were off. DD was also in the 75% while in utero, and when she was born at 41w3d, she was only 6lbs 13oz. My OB wasn't expecting that at all!

As long as she's growing on her curve then things are ok. Precise measurements are all estimations.

 

[brookmey]

I had several ultrasounds for DS since I always measured large to date with him at my appointments. For me, the ultrasounds were pretty accurate. We were told to give or take a pound each time.

A couple days before my due date, I had a final ultrasound, which measured DS at over 10 lbs, which is where I had estimated him to be based on the previous ultrasounds. He was actually well over 11 pounds at birth, so the give or take a pound was true for us. He was also almost 23" long. I did not have gestational diabetes and I was in a healthy weight range, so DS was just a big boy. He pretty much had no neck and had a big barrel chest.

Now he's 8 and is tall for his age, but skinny as a rail. People are shocked to learn how big he was at birth. DD, on the other hand, was barely 7 lbs and 19" at birth. Now, at age 10, she's 5'2" and 110 lbs.

It is shocking to learn you are carrying a big baby, but aside from causing you some extra discomfort, it really isn't a big deal.

 

[Mickeyluver37]

I wonder if technological advances play any part in the accuracy, or how old some of these antecdotes are. I will know in the next few weeks, but this baby was estimated at 6 lb. 8 oz. on October 1st at 35w5d. This totally puts him in line to be about the same as my other 3 babies who were all in the 8-9 lb. range if he comes between 39-40 weeks as they did. So, I'm guessing it's pretty accurate. I also see a maternal fetal medicine specialist with the high tech equipment that my regular doctor's office does not have, and that I didn't have with the first 2 kids at all.

 

[JVL1018]

They never estimated height, but they told me my daughter was around 7 lbs, she was 8lbs 6oz.
They told me my son was around 7.5 lbs, he was 9 lbs 5 oz. LOL.
They were both always like 95% on the height charts when they were babies-grade school.
I am 5'4" and my husband is 5'7". Go figure.
My dad is tall though, so you never know

BTW, after a chubby infancy(but not off the charts, like 70%, their weight was always less than their height percentile), I've always had two thin kids. So I wouldn't put much stock in anything measured in utero.