How accurate is the weight estimate from an US?

Re: How accurate is the weight estimate from an US?

• KayaXavier

  May 2012

  Linds1027:

  Hello ladies! I had a growth check US today (36 weeks today) and her weight came out to be 7 lbs 3 oz. I know that it can be off either way, but I am wondering if you already have kids, how accurate was it for you? I am a FTM, so I have no clue! lol! On top of that all the other measurements were all at least a week ahead. The majority of them we around 38.5. If it's accurate then I am looking at at least a 9 pounder by 40 weeks! Yikes! 

  They can be off by several pounds. I was induced because my daughter was estimated to be over 9 lbs and I was having terrible pelvic pain. She was born at 6 lbs 2 ozs and her weight dipped below 5 lbs in the next couple weeks. 

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• triagain2 member

  May 2012

  Former labor and delivery nurse here, I would be very hesitant to even get a late pregnancy ultrasound for weight check unless there was a medical worry, not to "see if its a big baby". They are normally incorrect by up to 1 lb in either direction. So if they say a 7lb baby, it could be 6-8 lbs. That pretty much covers 90% of babies. See why I think its useless. I think it leads to unnecessary c-sections by scapel-happy physicians.

   

  TTC #3 since Feb 2014 DS 1: 2010 DS 2: 2012

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• juliane2004 member

  May 2012

  ::lurking::

  With DD, at 36w1d, she was estimated to be 8 lbs 13 oz.

  She was born 4 days later at 36w5d, and was only 8 lbs 8 oz (so 5 oz less and 4 days later).

  It was close but not completely accurate.
  

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• summertimemomma

  May 2012

  its an estimate which can be off - especially if your LO is long

   DD was estimated over 9lbs at 41 weeks....she ended up being 8lbs 8 ounces

   

  i think it can be =/- 2-4 lbs 

  

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• pathfindermon member

  May 2012

  My doctor said it depends on how good the measurements the radiologist can take are.  If they can get good measurements (as in the baby is in the exact right position) they are fairly accurate.  My lo measured 4lb 5 oz at 29 weeks and 4lb 13oz at 30 weeks.  And that rate of growth is right on with what it should be, so it seems that the measurements were fairly accurate.

  

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• Kaiterz member

  May 2012

  It depends on the tech.  Mine was off by only a few ounces.
  

  
  

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