Growth scans weights - how accurate ???

[Newtothisstuff]

Anyone care to share their growth scan vs actual weights ??
2 weeks ago at 35 weeks DD weighed 4lb yesterday she apparently weighed 5.12lb
Just wondered how accurate they actually are ??? :-)

I have no clue I'm afraid. But i would assume they're relatively accurate or they wouldn't do them.

Sounds like you're cooking up a bouncer!

Ds2 was predicted to be 8lb 10oz from twenty week scan, my weight, height, bmi, age etc. he was 12 overdue and 8lb 8oz.

So think they can be quite accurate. Have they given you an indication of predicted birth weight?

He said about 6.5lb !! So not too bad

I'm sure he'll put on more than half a pound in a month??!!

Hmm. Not sure. I thought it was about half a pound a week in the last 4-6 weeks? I should know I'm pg with dc3! But I'm not certain.

Good luck though!

Sorry -I put he. I meant she!

Not accurate at all I'm afraid-this is fairly well known.

My consultant told me they are + or - 25% which is a fair bit.

DD was born at 35wks. Had a scan day before she was born-told it would be OK as she was already 6lbs 4oz. Crash section next night-was 4lbs 2oz! So that was about 33% out.

Take it as a guide only.

Good luck,x

I have her in 2 weeks.. I thought that 1lb 12oz weight gain in 2 weeks seemed a lot. DD1 was only 5lb 12oz so didn't expect a whopper but now I'm flapping a bit !!

Oh don't worry!

I'm sure if they were concerned about her size they would do something sooner.

What's the point of a growth scan if they are inaccurate??

Good luck and enjoy the last weeks of pregnancy

They're not terribly accurate.

They measure the baby's femur length, head circumference, and so on, then feed that into some equation to come up with an estimated weight. So if the sonographer gets the measurements wrong by even a few millimeters, that can make a big difference to the estimated weight.

I had a growth scan the morning I went into labour - they said DS was 3lb 9oz. He was 4lb 6oz when he was born less than 24 hours later, so quite a bit bigger than estimated.

Ah thanks :-)

Hi New, I had a couple of growth scans with DS and I think they came up with roughly the same weights as yours I think (only 2.9 years ago but seems longer). He was 6lb when born at 39+4.

I think they can be quite out but I think they check the placenta is ok, as part of the worry with a small baby is that the placenta isn't functioning as it should. As long as they were happy after the scan I'm sure all is good .

DS was estimated to come in at between 9.5 and 10.5 lb, I wasn't bothered as I'd read scans were often inaccurate by a lb or 2, and usually overestimated rather than under.

It was inaccurate.

By a lb or 2.

He weighed in at 11lb 7ozs just 12 days ago

at flisspaps

And congratulations of course!!

DS1 scanned at 38 weeks and estimated a 40 week birthweight of 9lb, he was 9lb10oz

DS2 scanned the morning of his birth at 35+3, estimated 7lb10oz he was 8lb

So not completely accurate but not as far out as flisspaps !!

I'm 36 weeks and had a scan this week to check on growth... estimated at 7lb 12oz and estimated due date weight of about 10.5lb... will let you know what happens!

Mine were estimated at 6lb 10 each for birth weight. Arrived 3 weeks ago. DT1 was 6lb 9, DT2 was 5lb 10, so a lb out.

They're not reliable, just an indication.