Large lateral ventricle and 3rd ventricle at 20 week scan

[emerald321]

Hi,
I was wondering if anyone has any experience they could share on this please. I had my 20 week scan yesterday and was told that one of the latetal brain ventricles was slightly larger than expected at 10.5mm (the normal maximum is 10). In addition the 3rd ventricle, which is apparently not normally visible at this stage, was clear in the scan and measured 3.3mm.
I've done some reading and believe the lateral ventricle measurement would only be classed as mild ventriculomegaly but its the 3rd ventricle I'm more worried about and I just cannot find any information on this.
I'm being referred to the fetal medicine unit for another scan, and have been offered an amniocentesis to check for chromosomal conditions and blood tests for infections.
I already had a clear NIPT result following a higher chance risk for downs syndrome at 12 weeks.
Just full of worry, both for the baby and my 3 year old daughter who is desperately excited for the arrival of little one.
Thanks for reading x

I am sorry, my baby had this picked up at a 34 week growth scan. I had the amino as the only risk at that stage was early Labour and it was a minute risk. The results showed no trisomy’s. I could have a MRI as I have metal in my body so I was a little anxious as consultant mentioned developmental delays.
Baby had a brain scan at two days old and everything was normal. They were monitored for a year after birth.
They are now two and a perfectly healthy toddler meeting milestones.
I wish I hadn’t been told tbh it caused a lot of unnecessary worry.
The chances of an issue are actually low but it’s a horrible time. Are you having the amino?

*could not have an MRI

Thank you for your reply. Do you remember if the third ventricle was affected too or what the measurements were?
That's really reassuring to hear and so glad your little one is doing well.
We didn't have the amnio for the 12 week high risk for DS due to risk involved but we are considering it now. Its such a hard choice x

Thanks, just looked back on texts I sent to my sister at the time. The third ventricle wasn’t affected and the measurement was 11mm.
The amino Is a harder choice at 20 weeks. I was already having care at a leading maternity hospital with in a fetal medicine unit. They are very experienced in aminos if you choose to go ahead with one. You should also be offered a MRI
I am sorry you are going through this

Hi Emerald.

I’m so sorry you’re going through this stress - I remember it well and it’s horrible. I remember googling third ventricle and getting absolutely nothing which was so frustrating and anxiety-provoking. Sending a hand hold.

It was a good outcome. I had the MRI and then met with the fetal medical consultant the week later. The third ventricle was looking a little larger than expected but there were no other abnormalities with baby’s brain. They said it was therefore most likely nothing to be worried about. I had another scan at some point later in the pregnancy and by that stage all the measurements were back to normal and the whole thing was forgotten about. Baby now a healthy just turned 2 year old.

I’m very much hoping for a similar outcome for you. Sorry you’re going through it.

Thank you so much for your reply @mintymcclinty. Thats great news about your little one. I don't suppose you remember the measurement you had?
I'm reading conflicting information about the expected size of the third ventricle. Most say 1mm but I've also found a post saying 4mm so I'm not sure quite how dilated 4.3mm is!
Just hoping it's encouraging news at the next appointment and the others vents haven't increased from 10.5.
It's such an anxious time. Just want little one to be happy and healthy xx

@emerald321 we've just had similar news with 4.3mm dilation. How did things progress for you? Hoping all is well. x

Any updates on this thread? X

Hi! So my little one is now 3 years and 4 months and she is doing brilliantly. Her ventricles continued to grow throughout the pregnancy and became 'severe ventriculomegaly', which after birth we discovered was caused by aqueductal stenosis. She had etv surgery at 9 months old and the ventricles have remained stable since. She is having 2 yearly MRIs to monitor. She has had some developmental delay but nothing too major. Mainly gross motor, (e.g late to hold up head, sit, walked at 2 years). She was under physio for a while but now discharged.
She's a gorgeous, happy, chatty 3 year old now. I think she does show some signs of neurodivergence at times and I think there may be some sensory processing differences (she can struggle with new, busy environments and I would say tires more quickly than a typical 3 year old), but hard to say if this is linked. She's still catching up on gross motor too, can still be wobbly and has a slow pace, but it's all stuff we see her improving in all the time.
Are you going through a similar issue in pregnancy? I'd recommend the Facebook group ventriculomegaly, I found that so helpful and reassuring during my pregnancy xx

Thank you for sharing an update. You had mentioned previously your concern more about the 3rd ventricle. Did that end up being the concern? We had an enlarged 3rd ventricle at the 20 week appointment measuring 3.3. Everything else measured normal. We are having a hard time finding much information so I would love your feedback about your experience with the 3rd ventricle. thank you so much! @emerald321