Baby's head measuring small at 20 weeks

[Lottie917]

Just had our 20 week scan and feel a bit deflated. DD's head circumference measured at 4th percentile whereas everything else measured within a more normal range. Overall she's on 24th percentile for weight, with AC at 50% and femur at 31%. No other abnormalities or concerns detected at this scan.

Anyone had this and it been fine? Just looking for people's recent experiences, or if anyone is currently going through similar and wants a hand hold/ some support too?

We've been referred to fetal medicine (apparently standard in my trust for anything measuring below 10th percentile). I had bloods done for a TORCH test today, results in 5-7 days. Consultant is going to call me within 2 days to discuss care plan moving forwards. I'm just wondering what to expect? Regular growth scans or be offered an amnio, etc?

The fetal medicine triage nurse and the sonographer I saw today said this sort of referral happens often and is often nothing to worry about, some babies have smaller heads and that's just how they're made genetically, etc. But I do know that it can also be an early sign of potential problems and a little part of me can't stop worrying that it might be something.

This is my 2nd baby. I never had anything like this come up in my pregnancy with DS. I'm trying not to Google what it all might mean as I know it won't do me any favours.

Any advice, support, experiences shared and hand holds much appreciated ❤️

Bump. Anyone? X

Yes me..
I had routine growth scans with DD2 (due to low birthweight DD1). The head measurement just kept getting smaller and smaller for me until eventually it dipped off the scale for two small. I was so worried about it.
DD2 was born on her due date (spontaneously) with a head measurement exactly on the 50th percentile for head circumference.
A lot of worry about nothing in my case, which I am very thankful for.
Good luck with the rest of your pregnancy OP x

@newandconfused5 thanks for replying and sharing your experience. I'm so glad everything is okay with your DD.

If you don't mind me asking, did your drs ever offer you further testing to rule out possible chromosome abnormalities or genetic problems? X

My 5th baby dropped down and down the charts until their HC was well less than 1%. They were born completely healthy and symmetrical. Fetal medicine told me the difference in head size between 1st and 50th is about a cm.

@TMess I can imagine what a worry that would have been! Glad they were okay and you got a positive outcome! That's also a very good point, I do keep trying to remind myself that if they weren't able to get an accurate measurement, even if it's off by a couple mm, it would make all the difference to the percentile given x

No, no extra testing offered, due to the sizing dropping right at the end of pregnancy.
I too have heard that the difference between the percentiles are fractional, also if you are being scanned by different sonographers, then human error (well not error but different techniques) can also play a part in the tiny differences between measurements.
I went on to have a third child and needed growth scans again. I actually requested to limit the measurements (so I wasn't being measured by midwife also) as it was so stressful with my second pregnancy.
DD2 is now 4 and healthy and way too full of beans!!

@newandconfused5 that does sound so stressful, I don't blame you for wanting to limit the measurements.

All being well this will be our last pregnancy so I've got everything crossed we end up with a similar outcome 🤞

I think it's just the wait for the call from fetal medicine and wanting to know next steps, and getting the TORCH blood test results back. I'll feel better when I know what's happening and where we go from here I think. Thank you for sharing your experience, it's made me feel better 😊

Just wanted to update this thread for anyone who might come across it in future.

I got a call back from fetal medicine today. My TORCH blood test results came back clear. It also shows I've not had the CMV virus ever which is the one they were most concerned about (apparently 75% of the population have had it in childhood) so I just have to be really careful around my toddler and not share food / cutlery or kiss him on the lips while I'm pregnant.

The consultant reviewed our 20 week scan notes and images, and with the test being clear, she's not concerned there's any issue so we've been discharged. She thinks that our baby is likely going to be on the smaller side overall but is happy she's within range for her gestation.

Hiya I’m going through the same thing at the moment, my babies head came below 5th percentile so they referred me for testing of toxoplasmosis and CMV, mine came back positive for cmv as an older infection but I have no idea when I caught it or if that is a good or bad thing that I had already had it tbh, still made me anxious to not see a negative result.

I’ve been advised to have an amnio which I’ve refused for now as I’m only 23 weeks but will have it done around 28/29/30 weeks I think, they said it was my choice when I had it done so I’ve picked around then with the risk of miscarriage. I might change my mind as to when I have it but will definitely have it done, I’ve also been referred for growth scans every 4 weeks in the fetal medicine unit in London to check on the growth. It’s such a worrying time and I haven’t stopped crying so know how you felt! So stressful.

We had this too and went for a private scan who got a much better view of things as turned out baby was in a better position that day. Everything turned out to be completely fine! Dd is perfect & 18 months old now. Could you go for a private scan to get a second opinion?

@Catlover10 I'm so sorry you're going through this. The nurse I spoke to for my blood test said that the lab would compare it to my booking bloods. Apparently the level of antibodies can be compared so they could see that if I did have antibodies, they'd be able to tell if it was a much older infection or if I'd actually had it while being pregnant. Do you know if they did that for you? Or could be worth asking about if not?

That must have been so hard deciding on if and when you do an amnio. It's good that it gives you a definite answer but I can also totally relate with the risk of miscarriage. It's so hard isn't it to know what the best thing to do is. When is your next growth scan? It's good they are monitoring you but as you say it's such a stressful and worrying situation and takes away the excitement of pregnancy. I really hope that your scans go well moving forwards and that your baby is okay. If you ever want to come back to this thread for a chat, etc please do feel free xx

@bakewellbride I'm so glad things were okay for your baby. They did say there is a possibility it's a mismeasurement as she was in breech position. There was also a discrepancy between my due date at 12 weeks between two sonographers (I'd totally forgotten about this) - difference of about 4 days which sounds like nothing but actually if I put the measurement I got against the due date I wasn't given in the end, baby's head is on the 18th percentile and not the 4th. It's crazy how much difference that makes!

I did think about this and we've got a private scan place near us that I've been to a couple times, but I don't like the place too much so I'm not keen on going back there. But if I find I feel the need to get another opinion down the line in a few weeks we'll do that xx

Thank you, yes so apparently my booking bloods came back and it’s an old infection as well so I guess that’s a good thing, no active infection so likely to be last year or something before I was pregnant. I’m still worrying about all the other possibilities instead though! I know the amnio risk is only small but thought I might as well wait a bit until the pregnancy is definitely viable and a good chance of them being able to help the baby if I did go into labour because of it..so far they haven’t seen any other signs of genetic issues like heart problems or anything but obviously this doesn’t rule anything out as not everybody gets other visible signs, it is reassuring though that nothing else was found

ive got a growth scan at 24/26/28/32/36 weeks currently, so at least I have plenty to keep me going. Some of those later ones were booked because of diabetes though. It’s all so stressful and Google has made me feel so much worse!

Yeah I made the mistake of Googling 🤦🏼‍♀️ made it so much worse. Oh I see, that makes sense on the blood test results. It's good they are seeing you every couple of weeks, obviously the stress and worry of the situation is still there but with regular monitoring, if there is any issue it can then hopefully be picked up on quite quickly and it's good that currently they can't see anything else that might be soft markers for any conditions. I have everything crossed for you for a good outcome🤞

That's a good way to look at getting the amnio with being further on in pregnancy. I hadn't thought about it that way! I've got a growth scan at 34 weeks due to BMI being on the higher side, so it's just to check baby and placenta are still okay in there, but I guess if there is anything amiss they might find it then. Pregnancy is such a wild ride 🙈

I just wanted to come on and update again for anyone who may come across this post in the future.

I had my daughter 3 weeks ago and bottom line is that she is absolutely fine. Not a single person at the hospital said anything about her head size after she was born - which is definitely on the smaller side, none of her hats fit at all! 🥺 - but she looks totally in proportion (on 44th centile in the end) and there are no concerns of any problems.

At 28 weeks I got diagnosed with gestational diabetes so I had a lot more growth scans in my 3rd trimester. These scans showed that it wasn't a mismeasurement of her head at the 20 week scan as initially thought but her HC did seem to be very slowly increasing (up to 10th centile at 36 weeks) which was positive.

Her AC however went off the chart due to the GD and I had some others thing come up too towards the end, so I had an elective c section at 38 weeks to ensure her safe delivery. Ultimately the growth scans were wrong about her AC being so high and her weight - she was estimated to also be around 8lbs already at 36 weeks but she was born a teeny 7lb 1oz at 38 weeks.

I feel a bit sad that I spent a lot of my pregnancy worrying about things I needn't have worried about but ultimately I'm glad she's arrived safe and healthy x

Congratulations OP and thank you for updating!

I'm so glad that your baby is fine.

Clicked on this thread because I went for my 20 week scan today. Everything fine except the sonographer felt that the pulmonary artery looks dilated. I’ve been referred to foetal medicine for a scan on the heart by cardiologists. The midwife didn’t seem concerned and suggested that the sonographer was being over cautious. But it’s best that I attend tomorrow and find out sooner rather than later. I just feel like I received mixed messages today and I was just wondering if anyone else had experienced this? Nobody even told me what this could mean so I just feel a bit deflated.