Enlarged third ventricle - 20 week scan

[mintymclinty]

We had our 20 week scan a couple of weeks ago and it identified an enlarged third ventricle. We were offered amnio which we declined but we have been for an MRI scan and are getting the results this week. Just wondering if anyone else had experienced this and what the outcome was. Google is coming up surprisingly short, with most stuff relating to enlarged ventricles referring to the lateral ventricles which were fine in our case. No other abnormalities were identified. Any experiences out there?

Thank you.

@mintymclinty This type of issue is obviously very worrying, but often turns out to be nothing of concern. The outlook depends very much on how enlarged it is and if any other issues are identified. I assume you have had a consultation at a specialist centre? What were their suggestions?
If it is a truly isolated finding it is likely to be just a variant of normal, but I would expect that it will be suggest to check again during pregnancy to be sure that none of the ventricles are enlarging further.
Are you having a face to face consultation to get the results?

@Nanmumandmidwife

Thanks for the info which is obviously really helpful and reassuring. It was 3mm and I think supposed to be 1mm. No other problems seen so far but we’ve not had the results for the MRI scan yet. I had the 20 week scan in the fetal medical clinic anyway due to an unrelated issue and the Consultant was largely reassuring (“likely variant of normal but we’ll do the MRI scan to check. We could also do an amino if you want” type thing). Further appointment with her again this week to discuss outcome of scan. I know I should just wait but after initially feeling quite calm I’ve become quite anxious about it (I’ve a history of recurrent miscarriage to quite jittery anyway).

If it’s not a variant of normal do you know what can it be indicative of?

Something like this on it’s own is very likely to be nothing significant. However, am MRI gives much more information about the structure of the brain, so is a way of checking that it is just one unusual feature. It is only if two or more things are found that it is reasonable to start trying to work out if there is an underlying diagnosis. In the absence of other findings it is frankly pointless to try to guess what the reason might be.
Try to remember that until very recently we didn’t have technology to see such variants, so probably lots of people have them, we just don’t know & so don’t worry.
Once the MRI is reported your consultant will be able to be a bit more specific. Without knowing the background about why you were seeing fetal medicine consultant originally I may be missing something. happy to discuss by private message if you prefer
Waiting and not knowing are very hard. Wishing you answers soon x

Hi, I know this was posted a few years ago, but I've just posted about something similar. www.mumsnet.com/Talk/antenatal_tests_choices/4529839-Large-lateral-ventricle-and-3rd-ventricle-at-20-week-scan?msgid=116629375
I was wondering if you would mind letting me know how things went for you @mintymclinty? X

Hi Emerald.
Will just go and read your thread now and post there.

In case anyone else comes across this thread looking for answers I just want to add an update.

The results of the MRI confirmed that the third ventricle was a bit larger than expected but found no other brain abnormalities. The consultant therefore said it was most likely nothing and given our history of miscarriages we didn’t have an amnio. We had another ultrasound scan later in the pregnancy (for an unrelated reason but they checked this at the same time) and by then the measurement for the third ventricle was in line with what would be expected. Baby now a healthy 2 year old. Hope anyone else going through similar worries gets the same result.