Growth scans. How accurate?

[wowiesis111]

Hi.
Due my second in June.
First was small. Born three days late and only 5lb 6. Apparently he had measured fine until about 37/38 weeks when They noticed he was on the small side so did scan and predicted he would be 6lb 8oz. He wasn't. He was 5lb 6.

This time because of the traumatic birth and with low weight I'm under consultant care and have had extra scans to keep eye on baby's size.
So far they have said he seems to be measuring ok.
At almost 31 weeks he's apparently 4lb 6 oz already according to their charts.

Two things.
What weight should I expect to deliver at full term if he's 4lb odd already ( with 9 weeks or so to go?)

Also have they told you weights at scans and actually been right in what they predicted etc?

Keen to hear experiences.

Thanks

Scan on due date predicted 9lb ish,
Born three days later at 10lb 6oz.
Even the sonographer said it was pretty pointless scanning for size at that stage as it was not very accurate.

My friend had a growth scan and was told it was 12lb so she opted for a c section. Baby was 9lb. I don't think they are very accurate.

If they are right he should be 9lb odd at birth (half a pound per week is the rule of thumb).

Omg!! Tumble!! 9lber!! That scares me. I wished for baby not to be tiny like first but a 9lb'er that's big!!
Ouch!! I'm not big myself so this would seem massive.

I guess they over predicted last time by a lb so if 9lb could be an over prediction , 8lb would seem more 'manageable '
Anyone else?

My friend was told a 10lber following growth scans and he was born at 7.7lbs...

There should be a growth chart in your notes, which they should have marked the rough estimaye going by your growth scan and you can follow the line to the 40 week estimate, just convert grams into lbs, it's really only a guess though

I thought if I eat more it would help the baby gain weight but it may have gone too far the other way. I did think his movements were a lot stronger than dc1s.
Perhaps I'll have to start being a bit better with portion size. I'm not big myself. A size 10 now at 31 weeks ( normally size 8).
I'm just wary as last time they told me one week that I was having a big baby and that I had no water only for the following week , to be told he was very small and I had lots of water. They got it wrong then so I'm unsure this time around whether to take it with a pinch of salt.

31 week growth scan my DD was predicted as being 4.8lb, she was born at 38 weeks weighing 8lb 2oz.

I had a scan about 2 weeks before she was due and they said roughly 7lb so were roughly correct.

My first was 9lb born at 40 weeks, didn't have growth scans with him.

This time baby was measuring average at the 20 week scan, I have another growth scan next week so will update then, but my stomach measurements are currently 3 weeks ahead.

Do not adjust your eating habits - it will have no bearing on your baby's weight.

Extra food goes on Mum not baby.

I'm concerned at how accurate too, having second growth scan (2week difference) due to going in twice with feeling some reduced movement and although everything on trace and scan have been ok They are then going to use today's growth scan to decide to induce now at 37 weeks or not- no idea what to do!!

Thanks

I'm gong to perhaps have to rethink baby grows that I've bought then too.
Was thinking id reuse dc1 s as they are very small and had bought a few newborn but these only go to 7lb. May be opposite to first and need more 0-3's!!

wowiesis111

I would keep what you have and get some 0-3, chances are baby won't be big.

My OB guesstimates size with a 10% margain either side

My dd1 measured 5lb 10 at 32 weeks but was born 8lb 1 @39.3
Dd2 didn't need growth scan as was average all way through pregnancy and was 8lb 11 at 40.4

They aren't accurate at all!

As far as I'm aware, growth scans are not at all accurate at predicting the baby's weight, but are done to make sure that your baby doesn't stop growing between two or three scans. By the sounds of it, due to your last being tiny, they are making sure that #2 doesn't have any IUGR issues. Hope that helps!

36+1 they said baby was about 4lb 3oz. He was born at 36+3 at 5lb 5oz so not accurate at all for me!

I had growth scan every week from 33 weeks as baby was measuring 2 weeks smaller and at 38 weeks they had her weight at 6LB 6oz and she was born at 41+3 at 6LB 9OZ so obviously they were wrong as she should have gained more than 3oz in 3w3d

They go on trends more than actual weights - the position of the baby, the sonographer...all play a part in accuracy. DD was scanned for growth a couple of times (28 and 34w) and both times was between the 9th and 25th centiles - she was exactly there when she was born too.

I would not take them as gospel. My Brother and his partner had a terrible scare last week when she had a scan and was told that at 39 weeks the babies arms and legs were not developing properly and was measuring small. They were being prepared for dwarfism and a syndrome of some sort and she was told she would be having an emergency C-section later that day.
Turns out the entire baby was small and my gorgeous perfect little nephew was 5lb 15! From that experience i wouldn't worry too much as you will never know until your LO is here how they will be!

I had endless scans this time as I was constantly measuring small and still being sick (hyperemesis) - fortnightly for entire second half of pregnancy. Every single time they said he was dead on average though I thought all the way through he was smaller than DS1. After all that, I was right (though he was 3kg, so fine, no health probs; but a good bit smaller than average). So in my experience no, they are not highly accurate. I did find one entertaining study that concluded that if a woman was having a second or subsequent baby simply asking her whether she thought the baby was larger or smaller than previous babies was actually more accurate than a scan!

Growth scans for weight aren't accurate at all in the third trimester. They are quite accurate for length and head size though, which is what they actually measure. A long heavy baby is a lot easier to push out than a small baby with a massive head, so don't panic about weight.

I had a small first baby (4lb 11oz) and extra scans for my second. At 32 weeks she was measuring big and the sonographer sent me off to see a consultant because I was measuring two weeks ahead. She was born 2 days late and weighed a perfectly average 7lb 1oz