Pregnancy scan query

[Duedatequery]

The baby's due date according to LMP is 15th March , but this (private) scan was done at 26 weeks , the sonographer said it's a big baby and the due date is Feb . Can anyone tell me what all the measurements mean please?

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What’s your due date according to your dating scan?

I would have thought the earlier scans would be more accurate as its easier to date the pregnancy by the development of the foetus earlier on. A big baby doesn't necessarily mean your due date will move forward.

@ChickpeaPie 15th March

I'm not pregnant, it's my daughter and she's asked me to ask .

She's a bit worried as the sonographer said the head is big.

Growth scans are notoriously inaccurate. If she’s worried about a big headed baby because of birth fair enough but all babies heads feel big when they’re coming out your vagina!

The NHS scan around 12 weeks would have revised the due date if necessary. So eg I had a due date based on last monthly period (LMP) which was then adjusted at the 12 week scan by 5 days.

I read that later in pregnancy babies vary much more in their growth so it's very unusual to re- calculate a due date after the "12 week" scan.

The head being big isn't an issue by itself- it's the proportion to other measurements.

They made my DCs head out to be off the scale, massive. DC came out with a perfectly average sized head. I'd not take much notice

The date the NHS go by is the one from the 12 week scan. They don't move that date based on subsequent scans, because the 12 week one is the most likely to be correct. I also know people who absolutely knew the date of conception and were told the 12 week scan overrides that!

I don't know what all of those are but HC is probably Head Circumference, AC Abdominal Cavity and FL Femur Length. Then at the end of the line I think there's a percentile for baby compared to others with a due date of 15/3, then an estimate for gestational age based just on that measurement.

Am I right in thinking the due date on the scan info is 29Feb? So baby's measuring about 2 weeks ahead. I don't think I'd panic at that, particularly given the inaccuracies you can get in scans. It's worth her mentioning at the next midwife appointment - they might want to scan her again in the NHS system to check everything's ok.

The opening post doesn’t make sense. If the due date is 15th March from the dating scan then this cannot be changed. Especially not by a private sonographer at 26 weeks. Baby can be measuring ahead but the dates don’t change

@110APiccadilly yes , the 12 week scan said 15th March and this latest one says 28th Feb .
@ThickSkinnedSoWhat according to this scan the head circumference is >99% Hopefully it's either wrong or the head stops growing!

Mine was the same and I will admit I had a big head as an infant so it made me very nervous but DC clearly did not actually inherit my big head and it has always been a perfectly normal size. I have known others to be told similar