Inaccuracy of ultrasounds- then what? - Page 2

[crystal_buffaloe]

I'm not sure this adds much to the discussion, but I feel compelled to share. I had an u/s at 41+3 where they estimated the baby would be 10 pounds, 4 ounces. I said "No f*ing way! No f*ing way! I only gained 19 pounds!” I ate right, I exercised every single day, sometimes walking 2 miles in the morning and doing water aerobics in the afternoon, I did not have gestational diabetes. (I weighed 188 pounds pre-pregnancy). Everyone looked at me and tsk-tsked about me and my gigantic baby. I agreed to an induction at 41+5 (big mistake!) in part because I was starting to doubt myself and getting scared about the "big baby," even though I knew the u/s that late was unreliable. I dilated to 10 and pushed for 4 hours (the hospital time limit) and was bullied into a c-section by an OB who referenced the u/s results despite my protestations. DD was born at 41+6 and weighed ... 7 pounds 5 ounces. The next morning, the first time I saw the doc since the surgery, he was kind of sheepish. He came into the room at 5 o'clock in the morning and I was breastfeeding my baby. He said "Well, she was asynclitic, which means blah blah blah." I didn't say a word to him.

[caned & able]

When ever an expectant woman is threatened with induction, ALWAYS ask for a Bishop's Score.

http://www.childbirth.org/interactive/induction.html
http://www.amazingpregnancy.com/preg...icles/173.html
http://www.suite101.com/content/usin...uccess-a107982
http://en.wikipedia.org/wiki/Bishop_score

Just another pondering:

How often do you think those scales are calibrated in the delivery rooms?

[homemademom]

Originally Posted by jeminijad

I am certain that some techs are more skilled than others, just like every other job. But it isn't like choosing a plumber, where you can check angie's list! That one person's adeptness, or the repair of their machine, etc can result in drastically different care for a mother and child.

It is good to hear of those who have had accurate ultrasounds- but in my personal experience (admittedly, only about a dozen,) I have yet to come across one that was within 1/2lb.

Oh yeah, I wasn't making an argument for late ultrasounds as good measures of macrosomia or reasons for induction. In fact, neither of my u/s's had anything to do with size, the OB/tech just told me as an FYI. Which leads me to believe that bias may have a lot to do with how big an OB says your baby is. As in, the more he/she wants to induce, the more he/she will fudge and say your baby is HUUUUGGGE to scare you into complying. In other words, maybe the technology is not as backward as we think, but the interpretation is filtered through someone with an interest in manipulating you. I really try not to be that cynical, but you never know. . .

[liberal_chick]

Originally Posted by mmaramba

I'm not even sure it's terribly dependent on how skilled the tech is, honestly. You'd expect them to be accurate (with a 1/2 pound) a significant percentage of the time, even if they simply guessed a number between 6 and 10 pounds.

I have a question-- how can you tell from an ultrasound how HEAVY a baby is? I'm honestly asking. Is there something I'm missing?

You can't guess weight consistently within 10-20 pounds by looking at a grown person outside the womb, and that's generally 5-20% of their weight. That's the equivalent of 4 oz to 2 lbs for a baby, and again-- that's outside the womb, a LOT easier to see than via ultrasound.

I'm 5'2" and weigh about 160 (I'm not pregnant). I don't visually present as significantly overweight, I typically wear a dress size from 4-8, and even my largest designer slim-fit jeans are a 30 waist. The largest non-vintage item I own, period, is a high-end size 10. Yet I would be considered clinically obese if I gained 3 pounds. Everyone who has seen me in person is surprised at my actual weight-- I've even had more than one stranger check my ID (which actually says I weigh 155, LOL) and ask if I've lost "a lot of weight" recently. I guess they could be feigning surprise and fudging downwards, but I buy it. I have a lot of muscle (concealed by some lower body fat), and dense bones.

CPD (and "CPD") has little to do with weight anyway, so WTF? Sure, a baby weight of 14 pounds is probably correlated to a big head, but under 12 pounds or so, who knows? My head was FAR bigger than my brother's, and I was only 12 oz heavier. And of course, positioning is the far more significant issue, but little if any attention is paid to that.

I don't think these estimation errors, which tend to skew over rather than under, are made with the conscious intention of scaring women into C/S. But I do think that when you're a hammer, everything looks like a nail, and when you're an OB, almost everything looks like a potential C/S, and that tends to trickle down to techs, who may "see" bigger babies than are there, on average. You're sued for the C/S you don't do, not the C/S you do, and all that.

But the bigger question is why this is even an issue. Why more than the most fleeting bit of attention is paid to weight estimates-- not to mention ultrasound "redating." And the answer, again, is the vicious cycle of CYA obstetrics has caught itself in the middle of. When in doubt, it's a C/S. Do that enough and you've never even seen a woman under 5'2" give birth vaginally, so the next 5' woman you see, start preparing her at her first appointment for her probable C/S. You've never seen an uninduced woman give birth, so you start to think all 41+ week babies will die without one. Etc., etc., etc. But when that baby the mother thought was at 36 weeks, but you "re-estimated" at 40 weeks-- or that 5 pounder you estimated at 9 pounds-- comes out needing a ventilator? Thank goodness they were in the hospital! Otherwise they would have died!

As to the bolded, they really can't. All it is is an estimation that is gathered by measuring the head, tummy circumference, and femur. They take those measurements and average them and, viola!, estimated gestation and fetal weight. I don't exactly know what goes into all the math, but my aunt is a u/s tech and that is how she explained it to me.

[mmaramba]

That's what I figured, liberal_chick, which makes it that much more ridiculous. Weight means little, and they're not even really measuring weight... So the whole thing is a red herring.

[MegBoz]

Originally Posted by nia82

I know several women who were told 11lbs or 12lbs and out comes a 7 pounder via c-section... I don't think you can make the doctors responsible for anything, as you signed consent papers.

What kind of logic is that?! 'You consented to the CS, so you have no recourse?' Well, those women consented to the CS based upon the fact that they had 12 pounders. If the 'fact' that they had 12 pounders is totally wrong, then how can you say , "Whoopsie! Sorry, but you consented! Tough luck."

That's like if my Grandmom consented to her mastectomy based upon being told she had breast cancer. If she later found out they swapped her records with someone else's, or someone totally incompetent reviewed her mammogram results & thought there was cancer when there was nothing wrong, then too bad, the doc is "not responsible."

While I'm not going to say it's necessarily cause for a lawsuit, I also would be flaming, spitting mad at any doc or anyone else who were to say, "Well, Meg, you consented, so it's on your head." The doc should at least apologize in a case like that (estimated 12, reality 7#.) Even if not to admit 'fault' - just to apologize for someone being in a bad situation like that.

Originally Posted by mmaramba

I'm 5'2" and weigh about 160 (I'm not pregnant). I don't visually present as significantly overweight, I typically wear a dress size from 4-8, and even my largest designer slim

Hi fellow muscular mama! I'm 5'4" and when I'm down to about 145, I wear a size 6, sometimes 8. Most people are also shocked I weigh that much based on looking at me.

But that's because muscle is more dense tissue than fat. Literally one pound of muscle takes up less space than pound of fat - so a muscular 145# 5'4" lady IS smaller than a not-muscular 145# 5'4" lady. (One of many reasons that, as a fitness instructor, I discourage people from focusing on "weight" & the # on the scale - body composition as well as health & fitness should be the focus & the things to base goals upon.)

But I think it's safe to say such variations don't exist in babies. My son wasn't pumping iron, leading to significant muscular hypertrophy in the womb. So based upon things like femur length is how they estimate weight - at least in the early US. So, in that regard, it doesn't strike me as quite as illogical. (Again, in the early US.)

But you hit the nail on the head here:

Originally Posted by mmaramba

CPD (and "CPD") has little to do with weight anyway, so WTF?

Even if the baby IS big - that doesn't mean go to CS! As I posted early, even ACOG does NOT recommend CS for suspected fetal macrosomia, so it makes me so angry that it's so common!!!!!!!!!

[mum4vr]

Like one PP, my late us was off bc my baby was BIGGER than expected. With my DD, 3rd child, we had a couple late us for breech presentation. (she did eventually turn)

My mw's exact words were, "She'll be barely 5 pounds, if even that! This'll be the smallest baby of your three!" (My boys were 7# 10 and 7# 11)

So, during pushing, I was thinking, no WAY this is a 5 pound baby! She was 8#4! Wow-- over 3# off.

But since I had a wonderful mw, she did not force or pressure anything I was uncomfortable with. She did exclaim about how wrong she was/ they were about the weight-- she said, "That baby must be closer to 9#! I can't wait to get her weighed!"

[mmaramba]

But I think it's safe to say such variations don't exist in babies. My son wasn't pumping iron, leading to significant muscular hypertrophy in the womb. So based upon things like femur length is how they estimate weight - at least in the early US. So, in that regard, it doesn't strike me as quite as illogical. (Again, in the early US.)


Is it really safe to say that? I'm not just talking about muscle vs. fat. There's bone density and all sorts of other tiny variables. I can't imagine that if you took 100 babies with the same cubic "volume" that they'd all weigh the same or virtually the same.

But of course, aside from that, there are the more important issues, upon which we definitely agree-- 1) how hard it is to make any set of accurate measurements from outside the womb, and 2) how little "weight" or even overall "volume" matters, compared to head size.... Not to mention, 3) how positioning in labor, which isn't measured by U/S and necessarily cannot be accurately measured ahead of time, is far more important than any of this.

[hildare]

i have a different story than some folks.. i really loved my ob. i felt as though he really had tons of experience and listened and learned from it, and was pretty intuitive. he told us we'd have a big baby, but just having caught so many births, thought that my anatomy would allow for birthing a large one...
he explained to me that they use a chart in combination with an us, to guess the weight, and that it wasn't always accurate. he suggested that if we were on the plotted graph he created based on those figures we were looking at a 9 pounder.
and she was TEN pounds when she was born. TEN. my first babe. delivered by c birth, not because of the size but waters broke and i never even effaced after 48 hours. (he suggested she was malpositioned somehow)
i think it's really a matter of finding a health care provider in whom you really can develop trust. they do exist.

[MegBoz]

Originally Posted by mmaramba

Is it really safe to say that? I'm not just talking about muscle vs. fat. There's bone density and all sorts of other tiny variables. I can't imagine that if you took 100 babies with the same cubic "volume" that they'd all weigh the same or virtually the same.

Yeah, good point. & actually, now that you mention it, Dr. Clapp's research on exercising in pregnancy showed that the babies of exercising women weighed less - they had less body fat - so they had smaller 'waist' sizes - but with similar head circumference, they weighed less!

So yeah, there definitely will be variation even with the same measurements. I just don't think the variations will be as great as they can be among adults with the same volume because of the muscle issue.