Ultrasound shows head small for dates. Is this as bad as it sounds?

[dundeemarmalade]

I'm not really sure why I'm posting this, but I don't really have anywhere else to go at the moment. We had our 36 wk appt on Friday at the birth centre where we were hoping to have our baby. All was going well until mw started to have a feel of my tummy - she said it felt like there was too much fluid and not enough baby, so we went across the corridor to AN clinic for another scan. Sonographer didn't seem too worried, but noted head circumference small, abdo circ bang on, femur length also short. So we were booked in, 'just to be on the safe side' to see the consultant on Wednesday, five long days away.
My parents had arranged to come over and stay Friday night, and they were v good at providing reassurance, but dh and i didn't really get a chance to think about things until this afternoon after they'd left. We looked at the charts again, and realised that the head circumference is actually very low, off the shaded area and therefore we think less than 3rd centile. Which is possibly very, very bad news. So now it's nearly four o'clock in the morning, and I've been trying to reassure myself that our baby isn't going to have congenital brain damage, but reassurance is pretty thin on the ground. Earlier scans were all okay, although head circumference was slightly below 50th centile at 20 weeks.
I've followed all the guidelines about what to eat and drink, haven't been exposed to rubella or anything, and can't understand how a baby that everybody said was perfectly normal at 20 weeks would suddenly go all wonky. I just don't know what to do. I know I should wait for the consultant to explain things, and that I'm no medic so can't really make a judgement about whether this really is a problem, but at the moment it just feels as though the bottom has fallen out of our world. We are both utterly grief-stricken and very, very scared. Please, if anybody has been in this situation before, please could you reply and just let us know how things went for you?

Cant help you sorry but will bump this to the top for you...............

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dundeemarmalade i have no idea but if i was you i would ring tomorrow tell them you need to be seen tomorrow! also post this in pregnecy you may get more replys

Don't have any direct experience but just to say that though the algorithms they use for calculating size are fairly accurate, they are based on the measurements the sonographer takes, which are prone to human error. Which is why so many people have babies that are eg 75th centile on the scans and come out at 50th centile or whatever.

So.... it might not be 3rd centile, it might be 17th or 25th or whatever, which would be a far less severe drop from previous measurements. DD2's head measured 25th or something with 50th/75th for everything else. Still does. She is (if I say so myself frighteningly bright. DD1 had an apparently worrying increase at about the same gestation but when they redid the measurements it went away. So I would expect the consultant to arrange another scan or redo it personally, one set of measurements isn't enough.

If it does turn out to be very small, then I suspect there are a fair few possible causes and some will be worse news than others.

Sooo..... I'm not saying "don't worry" because worrying is a perfectly rational thing to do in the circumstances. But it's still early days, I'd say.

Note that not all obstetricians (which is what the consultant will probably be) are created equal - some have a specific interest in difficult pregnancies or pre-birth diagnoses, and if you can get yourselves referred to one of those you will at least have the comfort that they know what they are talking about.

Hope some of that is helpful.

Ultrasounds aren't stunningly accurate and nor is head measurement. I was told my first would be tiny and had failed to grow. She was 8 and a half pounds.
I can't say there is nothing wrong of course but ultrasound is not an accurate picture.
here
Even head measurements done when the baby is out can vary depending on who is doing it, where they put the tape measure, if the child moves etc etc
I'm guessing they also loooked at brain ventricles. If they'd seen something amiss they wouldn't have waited till next week.
Hope it all goes ok

My sister in law was told in the latter stages of her pregnancy that her ds was small for dates. This was all because his head circumferance was small. He was 7.5 lbs at birth and was fine. He is now 13 and has no problems and a perfectly normal size head. Hope this reassures you and everythig is ok. I don't think scans are that accurate anyway..they told me at a 38 week scan that my son would be between 7 and 8 pounds. He was born 5 days later weighing nearly ten pounds!!!!

I was scanned every week from 30 weeks and was told that my baby's head and tummy were too small. Baby measured below the bottom centile the whole time. Weeks of worry and stress. Had a caesarean at 38 weeks and although my daughter was a tiddler (5 pound 6) she was perfectly in proportion and is now above the 50th centile at 6 months. I know it's easier said than done but try not to worry.

Agree with everybody that at this stage scans are getting more and more inaccurate, due to baby's size.

What I did notice about your post though was what you said about the femur length - I noticed this because this is what they found with my ds, and he has a form of dwarfism, which only came out in the latter stages of the pregnancy.

So what I would like to say is - e/mail me if after your next scan you would like to "speak" to somebody

emkana at gmx dot net

thanks everyone. some reassurance has been given already by a calmer look at the scan results - both measurements have slowed in proportion to each other - and by talking to family and midwives. we have an appointment with the consultant later today so hopefully will get some confirmation that what we have is a small, rather than a compromised baby.

I'm sorry you have had such a worry and hope your meeting with the consultant has been reassuring. Like everyone says, the scans can be very inaccurate for size. There is a huge range of 'normal' also in terms of head circumference. My dd2 was not diagnosed pre-birth, but does have a small head - if you feel you need to, I am happy for you to contact me. Do try not to worry though if you possibly can.

hope thats put your mind at rest dundee and that everything goes well. Don't forget lots of choccy for the birth, you'll need your energy