How accurate are ultrasound measurements in the last few weeks?

[Orlahoping]

I'm 36 weeks and at my growth scan yesterday baby was measuring in the 95th percentile with a 98th percentile tummy. I've already had 2 GD tests.

I'm meant to be being induced for mild pre-eclampsia next week or the week after so that's probably my last scan.

Given all my risk factors point to a small baby I am glad he is growing, but a bit concerned about the big tummy and what it could mean.

I don’t think the measurements are that accurate.
I had growth scans throughout both my pregnancies. With the one pregnancy I had a scan a few days before the birth - they were expecting my baby to be around 4lb, but actually my baby was over 1lb heavier when born.

Mine wasn't at all. Nor were the midwife's bump measurement predictions. I was told for months that he was going to be a really big baby but he was only 6 lb 6. They frightened the life out of me, imagining having to give birth to a big 9lb whopper, but he popped out like a cork!

It varies. I've just had my second and they were only 2oz off (and she was predicted to be a big baby throughout my pregnancy). My first, they over estimated.

My consultant said there is an error margin of 30% either way, but its the most accurate measure they have.

The size is usually fairly accurate but weight is often wrong.

I had a scan on the Friday that predicted he was 5lb 15oz and he was born on the Monday at 5lb 2oz.

I'm in the same boat, but the other way around. I had a growth scan last week at 34+5 and was told the baby had dropped from 50th to 10th centile so I am back in on Wednesday to decide if they need to deliver the baby, because the growth had dropped since the previous scan. They had the baby down as 4.8lb at that appointment. I hope all goes well for you!

Mine weren't accurate at all.

All the way through I was told 'bang average', 50th centile. 5 days before she was born I had a growth scan and was told 7.5lbs. Had her at 38 weeks (pre eclampsia) and she was a teeny 5lbs 10oz.
Family had to run out to buy tiny baby clothes and nappies.

DC1: Was told 11lbs, he was actually 8lbs.
DC2: Was told 9lbs, was actually 7lbs.
DC1 was measuring large from about week 28, but DC2 was on the 50th percentile until about 34 weeks then mysteriously got massive then shrunk by the time I gave birth. 🤣 I wouldn't mind but both times the HCPs involved in my care (particularly consultants) took the measurements as gospel and tried to use the sizes as a stick to beat me with when it came to birth choices.

@PrincessAnne4Eva this is the issue I am having. Felt a bit pushed towards a 37 week c-section.

I am seeing the consultant midwife tomorrow and hoping for a more balanced view.

Seems like they can be pretty far out!

Not at all accurate in my experience.

Hope it goes better tomorrow! If you need to, get Birthrights involved. They were amazing with advice and support to get the right birth when I had DC2. Although I'd personally prefer a CS for pre-eclampsia as it can escalate fast. I think it's the only circumstance where I'd choose to have another CS, TBH.

They've only mentioned C-section in relation to the potentially large baby. I'll ask tomorrow about what is best for PE (I am completely symptomless, my BP is controlled and the blood marker that led to diagnosis is no longer there). I'll look up birthrights as a few people have recommended them now.

@PrincessAnne4Eva I've accepted a c-section due to the pre-eclampsia risk...date on Monday for sometime in the next 10 days 🤯

A colleague was predicted to have a 9lb baby and they were born just under 7lb when born a few days later and another predicted to have a 9-10lb baby and they were 8lbish 10 days late

Good luck with it!

With DD1 I had a growth scan on my due date and they predicted her to be 7lbs 6oz, she arrived 5 days later and was 7lbs 5oz.

With DD1 they predicted a 9lber at 39 weeks, and the midwives were also saying she was big as my bump was just all baby. She was born at 39+5 and 7lbs 10oz.

I had growth scans in my 4th pregnancy. The one I had 12 hours before baby was born predicted weight of 3.74kg (continuing on curve from previous scans) and she was 3.71kg. I was told it's vital that the same person scans you each time.