Large head circumference - future health outlook?

[Greycushion]

I am due next month and my baby’s head circumference has been tracking above the 90th percentile all along the pregnancy. Other measurements are around the 20th-30th percentile so there is a significant difference.

I have searched plenty of threads on here and one reason seems to be familial benign macrocephaly (FBM) - in other words, big heads run in the family. But this is not the case in our family.

For other posters where FBM is also not the case, I have searched their posts in the years following their pregnancy and it seems there is an association between large head circumference and later learning difficulties, tics and autism. Published research also seems to bear this association out. So, I am trying to be prepared.

I would be grateful if anyone who has been in this position can share any advice. What sort of things do I need to keep an eye out for and at what age? Thank you.

This is going to sound a bit strange but have you measured your own head circumference? Or the baby's dads? My sons head circumference is on like the 95th percentile and the health visitor was monitoring it for 6 months or so after he was born but as it was tracking at 95 all the time and not going off the chart and there were no other issues she said it could just run in the family. This prompted me to measure mine and my OH's head and my own head is on 95th percentile for a female adult, which I never knew! Neither mine nor my sons heads 'look' big, but they still measure big when measured. Just thought maybe you could check? I know you said it doesn't run in your family but are you sure?

And btw both me and my son are fine. I also found out recently after mentioning this that my cousin had to have a special hat fitted for him in the navy as he had the largest head they'd ever fitted for. Still doesn't even look like he's got a big head. It's so weird! He is fine as well obviously.

My ds presented at birth with a very large head. In actual fact he's got a very thin long head now. It changed shape when he was about 4.

My ds was in the 90th centile for head circumference when he was born ((around 75th for all the others). His head was so big the gp proclaimed he had the biggest head of any baby registered at the surgery! He was checking for hydrocephalus but all was well. He just had a big head. He's grown into it now!

DS was born, I think, on the 9th percentile for weight but his head was on the 99th percentile. He is totally fine, just has a massive head. He's nearly 5 now and in age 10 hats.

All my babies have big heads as in over 99th centile. My husband and I do too. I am autistic, my son is autistic, my husband is undiagnosed but almost certainly autistic, my daughter is not apparently autistic. So for us the association overall bears out but I suspect we just carry the genes for both autism and big heads. I did have super easy and quick births despite big heads!

My youngest has a very large head. As a baby it was off the centile charts and always remained that way. He followed the same line on the charts and no one ever seemed bothered. He has always been very clever though - remarkably so. Many times as a toddler and pre-schooler he would say something and people would be taken aback and comment that they were amazed/had never seen someone his age be able to tell/read/calculate that. At primary school he was always way ahead of everyone else. At secondary he remains very advanced and wins lots of awards/competitions. In Year 7 he extremely well at an Oxbridge competition.
I’m saying this not to boast (I don’t know anyone on MN in real life) but to offer some reassurance to the OP that it doesn’t necessarily mean there is a negative cause, especially if health professionals aren’t worried.

Just say it’s centiles when it comes to growth charts, not percentiles.

My god daughter and her brother had really large heads from birth until they were about 6 and her mum called them onion heads. They are both in their 20s and entirely normal young people with great jobs and lovely personalities.

Do you have a fetal medicine unit at your hospital or in your area? If you are very worried, you can ask if you meet any criteria’s for a referral, even if it’s just for peace of mind.

Both my kids have large heads, but so do I, and so does my DF. I actually do have autism but I'm not sure they are not related! I have a verbal IQ in the gifted range if that is any consolation, and likewise I'm sure that isn't related to my head size! My kids are 6 and 2 and both are doing really well developmentally with no concerns, if that helps. The only issue I have is finding it difficult to find hats that fit, and I buy larger sizes than their ages for the kids hats!

Just to say they’re synonyms. The term centile is simply short for percentile. (Just to say have a Google if you don’t believe me.)

You clicked on a thread of a worried mother to be and that was your contribution? You not actually thought that thought but also decided it would be a good idea to type it out and post it?

Wow.

Thank you to everyone else for the reassuring messages; I’m very grateful for them.

My DS has a huge head - was on the 100th centile. He's 18 now and waiting his Alevel results- predicted very good grades. My DH had a huge head and had a first class degree in Physics. Both of their heads full of brains! However, I did have a big tear when DS was born.
I never heard of any medical condition associated with big heads thankfully. Try not to worry OP

Is there not a great deal of selection bias in your post research? You say that there are two categories of prenatal big head posters and then that all of the big head posters come back to mention development or other issues? Which suggests that not all in fact do - some just have big heads that run in the family. Are there no big head posters that never return?

I'm only asking because your comment about centiles suggests you're fairly likely to be statistically savvy and I wonder if you might feel better if we can spot your sample selection error?!

When my son was born his head was at 98 percentile. By age 4 my hats were too small for his head!

He’s 5.5 now and still has a big head. No issues other than being prone to bumping it!

My ds had a big head at birth. Went for his 6 wk check, and the Dr measured his head twice, looked at me, and said, "How tall is dad? 6f 2 inches. He said it's likely he will be tall. I'm 5ft. At ds one year check, the measurement was off the chart against his age. Health visitor asked us to make a gp appointment. I took dh too and explained hv concerns but ds was meeting milestones and could see Dh build (big and tall like a rugby player), so no concerns. Ds is now 11.
Average height (5ft, size 7 feet!) he just wore adult sized hats from a toddler, and yes, it's likely ds will be big and tall like dh. Ds body shape is just my dh.

My ds has a huge head, and always did. 99th centile for head circumference, but the rest of him was 50.
He's 19 now, at uni. Very very smart. I have just had to order a hat for him for a holiday from an online shop that specialises in XXL hats because we can never find one in a shop to fit him, but other than that, he's fine.

Both mine had big heads, dc1 was on the 97th centile, dc2 just below. Other than not being able to navigate my apparently suboptimal pelvis, no issues thus far.

My little boy was born with his head around 99th centile and it's still big now age 3 haha. He struggles with getting jumpers and tops over his head sometimes but other than that I haven't noticed anything else. In fact he's pretty bright (according to nursery). He can count to 30 (50 if I help him a bit) is reading some words already and can memorise things like he's got a photographic memory. Maybe there's a big brain in there haha 😂

My boys head is on the 99th centile, the GP said as long as his head continues to track the same centile they wouldn't be too worried. He's now 2, with no signs of any illness, disability etc. We just need to buy him age 4 hats 😁

My DH was the same very large head. Needed C-section. He has no issues infact he is a genius and very smart man.

DH is 5’8” and his measured head size sits on the ‘small-average’ size for a man. Grandfathers are 5’8” and 5’9”. There is definitely no familial benign macrocephaly to explain away the large head circumference in this case!

@Corksoles - if a poster stated that they had FBM as the reason then I didn’t advance search them further. Only the ones where there was no ‘reason’ identified.

Thank you to the posters sharing stories about how a large head circumference hasn’t led to any difficulties for their children. It is reassuring!

We certainly wouldn't have thought of using the term familial benign macrocephaly. In fact, I had a sibling with hydrocephalus, so we were on high alert for it. In our case, the child with the small head did have slightly enlarged ventricles seen on the scan.

I'm sorry this is worrying you so much. We had similar 'could be something or nothing' findings at every scan, and it's hard to know how to take it.

My son measured on the 99th percentile consistently for head circumference whereas he was the 50th percentile for his other measurements.

He's perfectly healthy.