how acurate are estimated birth weights?


so i went for my 32 week appointment today, i am having twins who will be born by csection at 36 weeks (i have to have a csec for medical reason and my hospital policy is to deliver id twins by 36 weeks) and today they gave me the girls estimated weights

baby A: 5lb 3oz

baby b 4lb 2oz

now baby bs weight really scared me as it seems so s small, i was just wondering how accurate they were.



at birth estimated weights for birth

10 Answers

  • 1 decade ago
    Favorite Answer

    After 20 weeks ultrasound size measurements can be off by up to two pounds or more, that's why the American academy of obstetrics guidelines state that fear of a big baby should never be a reason for early induction or c-section. ( sadly many doctors do it anyway). A friend of mine was told her son would be 10 pounds and he was only 7 Lbs 2 oz. But the measurements could be low as well. However, considering that your babies are being born a month early top of the fact that they are sharing space and nourishment those weights seem reasonable. I'm sorry to say this but you should prepare yourself for the likelihood that they will need to stay in the nicu for a while. Best of luck and congrats.

  • 1 decade ago

    Ultrasound weight estimates in the 3rd trimester can be *really* off just depending on the circumstances. I have a friend that was talked into having a scheduled c-section b/c they told her that the baby was going to be 9 lbs and that she was way too small to have a 9 lb baby vaginally - and then they pulled out a 7 lb baby at the birth. I know quite a few women that have been told 1 thing and then the baby was a pound or 2 different than the estimate. I would not be concerned about actual weights anyway - the babys' weights are not the thing that will determine if they are born healthy or how long they may have to stay in the hospital - rather the hospital staff will be looking to see if they are breathing well, eating adequately, and maintaining their own body temperatures.

    And even if those weights are completely accurate, the baby's are going to be packing on more baby fat for the next 4 weeks. Try not to worry.

  • ?
    Lv 5
    1 decade ago

    Normally twins are going to have smaller birth weights because many of them are born before your actual due date. 4 pounds is really not that small for a twin honestly. I know people who have a 2 pound twin and he is doing just fine now. As long as the doctor hasn't made you aware of any complications, you should deliver 2 beautiful healthy little girls.

    Birth weights are just basically a guess by where the babys position is inside your stomach. At my 36 week apointment my doc. said my son was weighing at over 7 pounds already. Well I'm thinking I still got a whole month to go and I was going to have an 8 or 9 pounder on my hands. 5 weeks later I was induced at 41 weeks and my son only weighed 6 pounds ounces. He was very small but healthy and happy.

  • 1 decade ago

    Their accuracy varies according to the scanners ability to see the babies clearly and are based on average weights for the measurements the babies are..sometimes they are spot on but most times they will be off by a few ounces either way.

    There have been times when the scans estimtes have been off but it depends on when the scan is done to when baby is born..after all no one can predict the speed the baby will grow week to week either.

    If there was any concern over your babies weights you would have repeated scans to ensure growth contiunes but looking at the weights of both babies i`d say you have nothing to worry about, Yes one is slightly smaller than the other and this isnt unusual either.

    Baby B`s weight at 32 weeks is a great weight most singleton babies would be around this size so to say your growing two in their thats a real great job. Try not to worry and enjoy the pregnancy towards the end.

    good luck

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  • Anonymous
    4 years ago

    I constantly warning women human beings to no longer positioned too lots inventory in weight estimations given throughout ultrasounds on the tip of a being pregnant. No device, no count how stepped forward, can incredibly recognize the load of your toddler while they're nonetheless interior the womb. The weights are calculated based off of measurments of the femur, backbone and skull. it quite is all in basic terms a time-honored formulation. i've got seen them finally end up close, yet i've got additionally seen them be some distance from precise. a ultimate occasion replaced right into a distinctive pal of mine who had gestational diabetes. She replaced into recieving known ultrasounds on the tip of the being pregnant to reveal screen the babys length. They ended up doing a scheduled induction at 38 weeks because of the fact they have been estimating her son replaced into around 8.5 pounds at that element. while the little fellow emerged after a 23 hour ordeal, he weighed in at a whopping 7 lbs. So, their device tacked and bigger pound and eight oz. on there. He probably could have stayed in utereo finished term and been merely dandy. ethical of the tale? Take it with a grain of salt.

  • that's a pretty good weight for 32 weeks, and i think that is the normal weight for 32 weeks too.

    I got a weight estimation at 37 weeks and it was 100% spot on. I gave birth at 38 weeks to a 5lbs 9 oz boy... this is him (so tiny)

    all the best

    he spent two weeks in NICU, 11 days being tube fed

  • 1 decade ago

    My fiance's cousin had twin girls about a year ago and they were at 36 weeks, thats about the weight they were too. For me, they told me son would be around 8 lbs and he ended up being 7 lbs at 41 weeks.

  • Anonymous
    1 decade ago

    I got an estimated weight today though it is just one baby and im almost 39 weeks along they said my son is about 7lbs so your babys are just a little under normal size for your stage in pregnancy they are gonna be little babys but they'll be fine still doctors may be a little off

  • Anonymous
    1 decade ago

    My oldest son was 7lb 6oz when he was born.

    & My middle son was 7lb 4oz when he was born.

    I'm pregnant with a little girl now(:

  • 1 decade ago

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