Ultrasound weight prediction accuracy

[mamamiran]

Hi, I am just wondering how accurate ultrasounds are in predicting the baby's weight. I am in my 37th week and was given an estimate of 7lbs. Any one else had their baby's weight predicted by ultrasound? How close to right was it?

[CallMeMommy]

This late in pregnancy they can be off by up to 2 pounds in either direction.

[veganf]

Usually it's pretty inaccurate. Statistically I believe a midwife/OB's guess by palpation is more accurate!

[Tenk]

It *could* be accurate with just one U/S to determine it, but off too. I have weight checks on Bodie every 3 weeks (so my next is Monday) and my U/S guy said the really only way to be accurate is if you're having them regularly to determine how much they've grown too. So 2.5 weeks ago he was 4lbs 13 ozs, they are anticipating he'll be no bigger than about 7lbs 5ozs when he's born in 13 days. We'll see tho, he feels smaller than my last based on how they sit in there and she was 7lbs 3ozs.

[just_lily]

I have been getting weekly u/s for about six weeks now, and twice they have predicted the same weight two weeks in a row. It all depends on how accurate they manage to get the various measurements, and doesn't mean she isn't growing.

For the last two weeks they pegged my little girl at 2.9 kilos (just under 6 1/2 pounds). Because I am getting the scans every week I trust that she will be relatively close to their predictions, but not set in stone or anything.

[mhenry]

I had an ultrasound five days before my ds was born. The weight prediction was 7lbs, he was 9lbs 13oz.

[Emily12581]

I had an U/S the day before DD#1 was born and it was off by 2.4 ounces. My midwives said statistically they are off by 10 ounces either way. Palpation is even less accurate, especially in my case where they told me I was having a 7 lb baby and a day later I had a 10 pounder. Mothers usually have the best idea, and heredity is a factor too.

I just had a U/S with this one and it said at 36 weeks she was appx 8 lbs, which would give me another 10 lb baby appx....which is pretty believeable due to my history.

[Tiffanoodle]

I've heard it both ways. My aunt was told she was having a 9 pound baby. My cousin was 6#10oz. I had an u/s a week and a half before dd was born and they told me 6#8oz at that point. She was born 7#1.5oz. So they were pretty close.

[Sasha_girl]

Lurking from August ddc--

I was told, from u/s, that my older son would weigh the same as my daughter had weighed at birth. She had weighed 7 lbs 1 oz. He weighed 8 lbs 14 oz.

[BetsyS]

I was just coming here to ask this question again.

I had an ultrasound today. They estimated my baby at 8 lb. I'm almost 39 weeks, and I can't really fathom my baby being that small. I'm thinking the baby is more like 9 lb or so. So, we'll see if it turns out accurate or not.

[kamesennin]

I had an ultrasound for size 2 days before I delivered (I had GD and they want to make sure I don't have a 15 lb baby ha ha). They estimated 7 lbs 6 ounces and baby's actual weight was 6 lbs 15 ounces.

[Kidzaplenty]

:

[madiesmommy]

The estimated dd the day before she was born at 8 lbs. She was 6 lbs 10 oz. This time the estimate at 28 weeks was 79th percentile (putting ds at almost 9 lbs at birth at 40 wks) and this week was 55th percentile (putting ds at just under 8 lbs at birth at 40 wks). My midwife felt of him, and did not get a good feel, but she says to expect 8-9 lbs off what she feels...that he is average and LONG and can carry easily whatever weight is on there. Ultrasound is all subjective where they measure on those white lines, so that is why it is so off alot of the time.