How accurate are growth scans?

[maria94]

According to my growth scan, baby is measuring almost 9 pounds at 38 weeks! Im happy she's nice and healthy but I'm worried I'm going to go overdue and she is going to be huge!!

How accurate are these growth scans?

At 38 weeks I was predicted a 10+lb baby, I had DD at 39+4 weighing a very sensible 7lb10.

But with DD1 I was predicted a 6lb baby at 39 week emergency growth scan - she was a sensible 7lb7.

People's experience of growth scan accuracy varies a lot. For me they have been fairly good. DC1 predicted 10th centile born on the 6th (last scan a few weeks before birth), DC2 growth scan 4lb2oz born 2 days later at 4lb6oz, DC3 scan 6lb2oz born 4 days later at 5lb13oz.

They were off by more than 2 pounds with my SIL.

Mine were reasonably accurate (predicted 50th percentile and he was just that) but there is a lot of room for error

It varies a lot, 1st one said my dd was not growing and predicted 5lbs at most... she was 7lbs 6oz born a few days later.

Then 2nd pregnancy predicted around 8lbs, ds was born 2 weeks later 8lbs 14oz at 38 weeks gestation.

All the midwives said big ones come out easier 🤷🏼‍♀️

Totally useless in my experience. Far off the mark very time.

Thanks everyone, sounds like they aren't the most accurate things in the world then! No one has said she is worryingly big, just on the larger side so if they aren't worried then I guess I shouldn't be either! She'll come out one way or another even if she is huge😅

Mine was accurate. 77th centile (6lbs 14oz) at 36 weeks. Born on 75th centile at 8lbs 12oz at 41 weeks.

In my experience they are BS but I’m still getting over the idiocy of my local hospital. Cut a long story short, they mismeasured my Dd. Thought she hasn’t grown since previous scan, panicked me, induced me and a rather long painful 47hours later she arrived. And oh low and behold they got it wrong!!
I’m actually umming and ahhing about making a formal complaint as there were many traumas along the way. Including DH breaking his ankle 🤦🏻‍♀️

My baby measured big all the way through (I was monitored for gestational diabetes) and predicted to be 9lb 8ish. She was 7 lb 12 (but long legged). I had nothing in newborn size, went straight to 0-3 and they swamped her for the first fortnight!

I got told from 20wks my baby was going to be big all mine are normally small so i was shocked worried all through this pregnancy ,she was born 6lbs 6onz she was my heaviest but still tiny she is now 15wks and just over 10lbs so dont worry x

Based on my experience and what I've heard from others, they can be way off.

I was told to expect a whopping 10.5lb baby at 38 weeks. Terrifying! He was 8lb5oz 🤷🏻‍♀️

At 38 weeks I had a growth scan due to concerns ds was small. Told he would be 7.5lbs ish at full term. Ds arrived bang on due date weighing in had 5lb6oz so no not correct in my experience!

Mine born were v accurate, with my 2nd it was measured a different way though they said . Based on previous pregnancy and my weight etc, therefore they said was more accurate.
I had a growth scan 7 days before she came, she was 5lb10 on that, she arrived and was 5lb12, in labour was the midwives prediction based on my scans and she was right!
My first they said at term he’d be no more than 6lb2, he was 6lb2!

So very accurate for me. I had a lot of growth scans with both though, they weren’t just one offs.
My first was 1st centile and my 2nd was 0.04th centile.

I had growth scans every 2 weeks from 26 weeks with both pregnancies .... so much more accurate than a one off scan

at 39+4 they predicted my DD to be 10lb4, she was born at 40+2 10lb2

there is meant to be something crazy like a 20% margin of error either way

Way out for me. I was told to expect a very big baby ( over 9lb) and he was just over 7lb. I had the wrong size clothes and nappies for him. As previous posters have said he was a long baby with ridiculously long legs and feet .

I had three growth scans - right up to 37 and a half weeks. I was told at each one baby was due to be around 10 pounds at term and was induced just shy of 40 weeks to prevent her getting any bigger. This led to an emergency section as she wasn't ready to be born at all and I didn't dilate. She was born at 8 and a half pounds, so not tiny but certainly not huge. They also told me the placenta was showing signs of failing and would deteriorate further if I went overdue and wouldn't be able to support her due to her size. The midwife who was present at the c section told me that the placenta was absolutely fine and there were no concerns when she examined it - I could easily have gone overdue with no concerns.

I'm not convinced of the accuracy as the team were adamant she would be huge ...

Mine was bang on from weight (just under 8lbs) consultant predicted at around 34 weeks!

I had several growth scans - at last one (36 weeks) I was told to expect a 9lb baby at term. In the end he was 6lb at 41+1... and I have to say the labour was horrendous in spite of his small size, there may be some truth to the idea that slightly larger babies deliver more easily.

My friend was induced at 36wks cause buba was 3lb something on the scan. He came out 5lb 5oz.

I had a growth scan at 38 weeks, they said DD was measuring at 6lb something and on the 15th centile She arrived at 42 weeks and was 8lb 1oz between the 50th and 75th centile.

Not accurate whatsoever in my experience. They said DC1 was average sized when I was sent for a growth scan at 34 weeks, he weighed 10 lbs!

Very mixed opinions.. I guess I will soon find out!!

Does anyone know if I'm in my rights to ask for an early induction/sweep to avoid going really overdue if baby is already measuring big? Not sure how it works. I've always had it in my head that you need a medical reason to be induced so I'm assuming it'll be a no. Im almost 39 weeks so not far off anyway. Anyone else had this? X