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the search is down, so i apologize for asking this probably often-asked question! my doctor told me that an ultrasound to check for size at 36 wks can be a pound off either way. anyone have it be further off than that? i agreed to do the ultrasound to make my doctors more on board and at ease with my upcoming vbac, convinced that this baby is much smaller than my son who was almost 12 lbs at birth. so as of today at 36 weeks, my baby is supposedly 7.5 lbs. not huge, but not the small bundle i thought i was carrying either! anyone who's had a late ultrasound please post how accurate it ended up being. thanks...
 

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My friend's dd was induced yesterday...<br>
they said the baby was well over 9lbs at 38 weeks with low amniotic fluid they had to induce ASAP... baby was born last night at six and a half pounds - that's hugely off.<br><br>
Never mind my bestfriend's "son" was born without a penis after 6 late u/s for placentia previa...it was a healthy girl...oops My GP said she'd only trust a u/s done by a radiologist with new equipment so sent me to a hospital for my level two one.<br><br>
I think they can guess length, or size of head but weight is a bit trickier IMO.<br>
My almost 11 pounder was easier to birth as he was in the right position than my 7 pounder who was face up. Good luck with the VBAC!!
 

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Later u/s to determine weight are NOTORIOUSLY inaccurate. I would not rely on an u/s for weight at all. Period. Certainly not for an induction for a "large" baby.
 

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I had NSTs during my last 2 months of pregnancy (for gd, come on, that's *high risk* when its diet controlled?!) and they said my son was going to be HUGE, *way* over 9 pounds. He was 7lbs 12 ounces. Woop. Totally off on the estimates there.
 

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Generally, fetal weight is estimated by the following measurements: 1). head measurements - temple to temple and circumference 2). abdominal circumference 3). femur (thighbone) length and sometimes humerus (upper arm) length.<br><br>
The problem with obtaining these measurements (in my experience, anyway) is that the head is often deep in the pelvis and extremely difficult to measure accurately. Also,babies tend to lay more on their tummies/side which makes an abdominal measurement difficult. Sometimes the mom is contracting, also making the scan more difficult. Add into the equation unsure LMP or gestational age (without serial u/s scans to establish a growth pattern) and your measurements can be as much as 2 lbs (+ or -) off. And keep in mind, this is all with the assumption that an experienced OB sonographer is scanning you with a newer model u/s machine <img alt="" class="inlineimg" src="http://www.mothering.com/discussions/images/smilies/smile.gif" style="border:0px solid;" title="smile"><br><br>
Best of luck with your delivery!
 

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We had one the day before he arrived. It said he'd be 8 1/4 lbs but I'm not sure what the margin of error on the machine was. He ended up 6lb 11oz. For whatever its worth, his head was VERY big and VERY low and I was contracting a lot during that time.
 

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I had a 35 week ultrasound with my daughter and they put her a bit over 9 pounds. She was born at 39 weeks, 11 pounds, 4 ounces.<br><br>
I had a 37 week ultrasound with my son a few weeks ago. Again, they put him a bit over 9 pounds. He was born 10 pounds, 6 ounces at 39 weeks.<br><br>
Honestly, my doctor didn't put much stock in either ultrasound (her colleague sent me both times, she didn't). My doctor was much closer on weight "guesses" with both babies by just measurement and touch.
 

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My good friend was measuring small towards the end of her pregnancy so they did a late ultrasound. Doc said the baby was going to be 6 lbs. He was 8lbs 13 oz. Just a little off!
 

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I had a sizing ultrasound at 38 weeks to see how large my dd was ( I had GD), and it was only off by a few oz when I delivered a week later. It might very well come down to interpretation of the person doing the ultrasound rather than just relying on what the equipment says.
 

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41w3d us said 7.5# and still 2 weeks from "due" (I cried when she said that, but I knew she was clearly wrong because we KNEW our dates)<br><br>
born 41w5d - 8#13 - in hindsight, I think if she had told me 8#, I might have had a more difficult labor, but I'm still irked that she was so very wrong - and especially sensitive when moms swear by us weight "guessing".<br><br>
--janis
 

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At 35 weeks, an u/s estimated that dd was 6.5 lbs. She was 4 lbs. 12 oz when she was born a week and a half later.<br><br>
At 36 weeks, the u/s estimated that ds was 6 lbs even, and he was 5 lbs 8 oz when he was born 4 days later.
 
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