So i know weight prediction scans can be wrong, but what about the head circumference measurement?? Can this be wrong too??

(13 Posts)
DangerMousey Thu 15-Nov-12 23:02:18

Had a scan last week at 36+6 to check baby's presentation. He is head-down, which is good news as I am hoping for a water birth in the MLU.

Whilst she was there, the sonographer took a load of measurements of the baby too. She made lots of comments like "oooo, he's a big boy - look at his chubby face.....oooo he's got a large belly as well." thanks, very helpful for a first time mum facing labour!

She estimated that he was already 7lb7oz and that if i went to 40 weeks he could be a 9lb baby, or even more if i go overdue.

I am taking this with a pinch of salt cos i know these weight estimations can be waaaay out.

However, i am a bit worried about the measurements she took...his head circumference is on the 95th+ centile, and his 'biparietal diameter' (another head measurement) is actually off the scale...literally, in my notes from the scan, there is a cross about half a centimetre to the right of the 100th centile hmm

Is there any chance these measurements might be a little teensy bit off too?? I am worried about having a baby with an enormous head..will it get stuck?? Or would my body not have grown a baby it cannot birth??

Anyone with experience of having a massive-headed baby predicted, who had a normal sized one emerge, please tell me your reassuring stories!

Posterofapombear Thu 15-Nov-12 23:06:18

My scans assured me I was having a tiny baby with a tiny head. 9.2oz with a head circ on the 95th.

They just make shit up.

Any fool with eyes could have guessed the size of DD without a scan, in fact most of the midwives had it right to the oz.

So I would take it with a pinch of salt.

maxbear Fri 16-Nov-12 13:52:53

The weight estimation is made up from the head, abdomen and leg measurements I think so yes, it is entirely possible that this measurement will be incorrect. Scans at this gestation are known to be inaccurate due to the difficulty of getting a head circumfrence with a low down head, even if it is not yet engaged.

MrsHoolie Fri 16-Nov-12 17:59:31

I had 8 growth scans including one on my due date.
Even the sonographer at the last scan said it was a waste of time at that stage as they are so inaccurate.
He was estimated at 9lb ish and popped out 3 days later at 10lb 6oz. To be fair they said his arms and legs were off the scale and they were right. But then DP was a 10lb baby and we are both big.
Big babies are not harder to give birth to apparently. You can end up with a nasty tear from a 6lb whereas some massive babies flop out easily.
I had c sections so I have no experience in the pushing side of things.
Try not to worry grin

combinearvester Sat 17-Nov-12 22:20:31

To some extent the later the scan, the less accurate the measurements, particularly the head if they are already partially engaged.

We had many many scans with the 3rd pg which showed the baby as biggish but normal. Around 32 weeks one sonographer gasped with shock at the size of his head, then remeasured and sighed with relief - she had plotted the head as way way off the chart, then realised it was 75th centile. All subsequent scans the head was 75th centile.

Of course when the little bugger was born his head was way way way off the charts - that one scan had been right. His head was 42cm at his six week check, and he was two weeks early. His head was a weird shape which may have affected the way they calculate it, I know they plot their guess from two points.

PS I had no long lasting evil birth injuries.

crunchingautumnleaves Sun 18-Nov-12 07:37:19

IF it's a big head, a water birth should help. The key things to remember are upright, forward birth positions, especially with dry land births (gravity is your friend) & to let the natural pushes and baby do the work. If you feel the need to push, little pushes into your bottom like you're trying to do a poo. And breathing through the stinging parts rather than actively pushing as these are the times that your tissues are stretching. Some women also instinctively put a hand down to support baby's head or support/ease the perineum. This tends to happen a lot more in water births.

crunchingautumnleaves Sun 18-Nov-12 07:38:46

Squats and lunges are especially useful as they help the pelvis open to it's maximum amount.

Worley Sun 18-Nov-12 07:55:01

speaking as a Sonographer. scan sizes can have a 5 -7 day difference, over or under. we use the bpd as a Landmark guide whilst measuring. many hospitals sont plot this anymore. we don't judge size by it, it the circumference that's the one that's used to judge. everyone's head is different widths so don't stress about that.. sometimes well have a shift look at the parents and see what shape their heads are. we can't tell if the head is engaged but if the head is low is will make measuring it difficult, this Is why we tip you up on bed to try and achieve better views. also If baby is breech the head measurements come out bigger.
the stomach (AC) can be bigger depending on how full it's stomach is. it's the layer of fat around baby's tummy that can be tw best sign of what's to come. many diabetic women have babies with large tummies and we can see a diabetic baby with a large layer of fat around its middle.
what will be will be. sometimes we can be a little out but we're only as good as the measurements we can get.

when I had ds2 the Sonographer estimated his weight and was spot on at 5lb 4oz. ( I had him that day, I wasn't a Sonographer at that point)

Worley Sun 18-Nov-12 07:59:45

also agree with mrshoolie that the little ones births can be as much trouble as bigger ones; I had second degree tears with birth my tiddlers (ds1 was 5lb 13)
and no posterofapombear we don't just make shit up.. I think we'd be struck off if we did that.

FirstTimeForEverything Sun 18-Nov-12 08:00:34

Message withdrawn at poster's request.

surfingbabies Mon 19-Nov-12 11:05:41

My first twin had a big head, it measures off the scale even now and he's 8......it didn't hurt any more than his twin or my first child. I labour standing though as gravity works in your favour smile
Good luck & don't worry about it, relax and everything will be fine wink

hatsybatsy Mon 19-Nov-12 11:41:01

ds had a big head and a big tummy. they said he'd be over 9lb....

he was under 7lb but he did have a big head and a big tummy smile

I was told DD was going to be a massive baby, she turned out to be 6lbs 1.5 grin don't panic!

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