Small head circumference measurement at 24 weeks

[Katyhart]

Hi all, I’ve seen a few older threads on this, but starting a new one in hopes someone will come across this!

I’m 24-25 weeks pregnant, with a uterine abnormality after a complicated loss due to early TFMR - so: lots of additional scans.

Although nothing was flagged at my 20 week anomaly scan (happened at 22 weeks), my most recent scans (today and last Monday) showed my baby’s head circumference first at 4.2% and then today at under 3% (worth saying todays NHS scan measured against my due date, which I think is 2 days out).

Im waiting for an appointment with fetal medicine in Bristol near where I live. I know there is a potentially an extremely difficult ending here, but I’m going out of my mind anticipating that outcome and want to leave space for this to be ok.

Does anyone have any similar stories?

Mine is from a long time ago as my kids are now 20 and 16, but both of them had small head measurements on their scans. Ds2 was not such a big difference as he was a smaller baby all over, but my my ds1 had a head circumference on the 9th centile, a stomach measurement on the 95th centile, and was 75th centile for leg measurements. I had extra scans for ds1, but that was because I was taking part in a study the hospital was doing, not over concerns about his head size, but they did monitor that as well. I was very concerned, but the dr's weren't as they said the scans might not be completely accurate (as I said this was 20 years ago so I appreciate scans might be more accurate now), I think they said there was an error margin of 10%. Anyway when my kids were born, they were fine, they did just have very small heads. Their heads actually looked in proportion with their bodies, not like most babies do with a large head compared to their bodies.

As my kids have grown they did grow into their heads, but even now despite being 5ft 10 and a strong build, DS1 struggles with hats, even the smallest men's ones can be too big, so he often ends up with teen size.

I really hope the further investigations bring a good outcome for you. Do you have a date for your next scan?

Mine also measured small at 20w, at the re-scan she said it was just threshold 5th centile so didn’t refer. At my private scan last week she had it at like the 3rd centile. My dating scan puts me 3 days earlier than my ivf dates and I’m convinced it’s skewing it - If we were going off my ivf dates it would be in the 40th centile! I’m due a growth scan soon (32w) so hoping things have caught up.
did they comment on brain anatomy on the scans?
Good luck with your appt - really hope it’s just a dating issue x

Ah thank you for your message @Xwx1010 , good luck with everything!

There’s some kind of dating discrepancy - I had 2 scans within 4 days of each other around 12 weeks, the actual dating scan wasn't a clear view at all and put my due date at 17 December. I’m pretty definite on when I ovulated and I’m so sure the date from the other scan where the view was much better, 19 December, is correct.

Either way, I think their head is probably still probably too small - it’s just how “too small”. So maybe I’m making too much of that.

No flags for brain anatomy at 20 week scan and my more recent 24 week consultant scan where they referred me on to Bristol both doctors I saw thought the brain looked good/ structurally normal.

But I know there are things that better equipment/ more specialist doctors/ MRI might capture.

I’ve gone straight into feeling so sure that I’ll need to end this pregnancy too, so things feel really dark at the moment.

thanks again for commenting x

@Katyhart those few days could really be skewing it for sure and Normal brain anatomy is a good sign…
i read quite a lot of posts on here where posters had similar everything was fine with baby on delivery so fingers crossed for you/us too. If you feel up to it do let me know how you get on, everything crossed xx

Thank you @Xwx1010 ! Finally had my fetal medicine appointment today, they couldn’t find anything wrong with the way our baby is developing, just the same very low percentile HC measurement.

They tested for the relevant infections and we have decided to go ahead with an MRI and to seek out private NIPT - but the seemed to be leaning towards these being options on the table to help us rule out anything being wrong, as opposed to confirm anything that looks like it is wrong.

So, lots more horrible waiting for results, scans, MRIs etc, but I think today is probably a reasonably positive outcome, at least until anything else can prove otherwise.

Best of luck with your 32 week scan, let me know how it all goes!

My baby boys head circumference measured small aswell. So did his abdomen but his legs were average for his week. We were terrified his brain wasn't growing and he was going to be disproportionated but he looked perfectly fine when born and overall was on 2nd centile. They said the tests have a 20% margin error . He actually fell off the centile scale and he sees a pediatrician for reviews but He's 1 now and still really tiny for his age but a perfectly healthy boy ahead of his physical milestones

That’s really great news, I’m glad it’s a case of ruling things out - I know you have some tests to go but does sound really positive. Hope you can breathe a tiny bit now!
appt with consultant is Monday - feeling nervous but trying to think positively as it’s much more likely to be fine than not.
really helping seeing a other peoples similar experiences and all was ok! X

@Katyhart all ok my end too with head measurement (well for now anyway) - just in range and everything tracking along the curve as expected .
just a load of other complications to get through delivery wise now! x

Amazing @Xwx1010, every appointment where that’s the news is a win isn’t it and hopefully you haven’t got too many more appointments to get through now.

Sorry about the complicated delivery aspects - do you have a plan for delivery in place at the moment, or all a bit uncertain on that front?

Hope you’re OK, it’s all so much to cope with isn’t it and it sounds like you’re in the same boat as me in terms of having had a more complicated journey with going through IVF xxx

Adding an update here because I hated finding all these threads when I was desperately searching and not hearing what happened - I did an MRI, very broad NIPT and infection testing, all came back normal and my baby’s HC carried on growing along her teeny curve so I was discharged back to my local hospital after another couple of scans with fetal medicine specialists.

She was overall very small, although did keep on growing until the end of my pregnancy and was born by c-section at 37+5 in December (after I went into labour, was planned for 39+0!) weighing less than 5 pounds. She’s gained weight well since then, her head has grown and no-ones even measured it since about 8 weeks.

Hope this might be reassuring to those experiencing something similar x