Is the weight of a baby given at a scan accurate?

[ladyruskin]

This is really a question for second+ time mums...

I had a scan at 28 weeks which showed my baby to be weighing 2lb 14oz. The average weight at 28 weeks (according to BabyCentre) is 2.22lb which I take to mean a fraction over 2lb 2oz.

Does this mean I'm in line for a monster baby? Is the fetal weight from scans always accurate?

[Fuschia]

No

There is quite a big % variance

My twins were scanned on a weds and est 4lb 14 and 6.Lb 14

2 days later they weighed 5lb 5 and 6lb 4

[buggie]

I had to have lots of scans during my pregnancy as had unequal uterine artery pressures and gestational diabetes. The point of the scans was to check the bugglet was growing properly, and each time they measured her there was an increase. However, the weight estimates must have been way off - the last scan I had was at 39wks and their estimate was 6lb 3oz, she was born 6 days later weighing 4lb 10oz!

The bugglet was all limbs though which I think threw out the equation they base estimates on.

[Yak]

Not in my experience - yaklet last estimated at 7'10" at 39 wks which was his birth weight @ 41+4 wks. If you search for a thread I started on growth scans at Kings you'll see other's experiences

[EDmummy]

Agree with others. Even at 40+1 they didn't think my second was going to end up 10lb 4oz (even though I warned them about big babies in the family and that my first was 9lb 4oz)! I wouldn't worry anyway. My lovely 10 pounder is now a very normal sized 5 year old.

[laurac]

Ditto - I was told my first baby was going to be small to average size - she weighed in at 9lb 4oz. Second time around I was told not to expect such a big baby - baby number two weighed 9lb!

[ClareC]

They were spot on with both of mine!

[Ruth_Baldock]

WAY off with mine- I was scanned at 38wks, they thought he was a 10lb-er. At 39+3 he was born, weighing 8lb 6oz. I have been given similar guff with this once (currently 31wks) and I am ignoring it...

[ludoscotts]

they got the weight of mine exactly right.

[craigy]

i had a scan at 35 weeks with both that said they were around 7lb at that time and they both came out at 40 weeks at 9 and a half pound so pretty spot on...

[Mook]

Mine were pretty accurate - scanned at 39 weeks at 10lb, was born at 40 weeks at 10lb 3.

[nunheadmum]

I was consistently told that my first was a 'small' baby - I got scanned every few weeks from 20 weeks and went off buying premature clothes for when she was born, expecting her to be tiny......in the end she was totally normal and too big for all the clothes we had....my mum was delighted to have to rescue us with normal sized baby clothes.

If the scans are picking something up in terms of size then it's probably better that they are aware there is the possibility of there being an issue. It's better you/they anticipate a big/small one and then it doesn't happen than the other way around! But don't rely on it.

[BB100]

I was induced because Kings thought the baby was 4lb on the scan. She was delivered the next day 6lb 6oz so yes they can be wrong.

[Smiler]

way off with me too, estimated 6lbs14 and baby was only 5lbs10oz (37 weeks).

[hellosailor]

I was scanned on the day I went into labour and told my baby was 9lbs 12oz, and later that day she weighed in at 8lb 9oz, a friend was given extra growth scans because they kept telling her that her baby was small and she weighed in at 9lb 4oz.

[pommie]

they told me at my last scan (which was quite late due to having low lying placenta) that my baby was going to be big and she was only 7lb 11oz so dont stress too much