Nuchal scan results good, but nasal bone absent. Should I worry?

[thehuntress]

I had my nuchal scan at the FMC today. Bloods and NT were good, but they couldn't see the nasal bone. That gave me a risk of 1:692 versus a risk of 1:3000ish if nasal bone was present.

They told me that since I'm early (11w5d) that I should come back for another scan in a week as sometimes the nasal bone hasn't developed at this point.

I know my odds are good for my age (36) but I am still worrying. Has anyone else had a similar result, and had the nasal bone show up on later scans?

Also, I know that 75% of DS babies don't have nasal bones. Could the absence of a nasal bone mean anything else other than Downs?

[NumptyMum]

Bumping for you - I don't have any answers but know of others on here who have had scans looking in particular for nasal bone, but I think this was a little later than your scan so perhpas this is the difference?

Hoping someone will come along who has more information for you...

[katiecubs]

Hi there, the absense of the nasal bone is just a marker for downs or other cromosomal abnormalities and with your odds (bearing in mind your good bloods and NT) i think the chances are you have nothing to worry aboout.
From what i know they like to look out for this between 11-13 weeks which is when it calcifies by, as you are at the early end i'm guessing there a good chance it will be there in a week when you go back. Every baby develops a little differantly xx

[Mybox]

It's still early & your scan next week should show the info.

[thehuntress]

Thank you both for your responses. I'm feeling much better about things having thought about it logically over the weekend. With my DD, I don't think they even looked at the nasal bone. I think it is a relatively new marker that they look for (and a bit controversial in the medical world). Also, I know this may sound stupid, but you could see a very distinctive (and cute) little nose on the scan.

It makes you think that sometimes all of these medical tests that only give you a snapshot of things (without the whole picture) cause more worry than they are worth.

Anyway, I will post an update after my next scan in case anyone else has these sorts of questions.

Thanks again.

[thehuntress]

Our posts crossed Mybox - thanks also. I'm actually feeling much better about things now and not jumping to any conclusions.

[IsItMeOr]

Hi thehuntress, glad you're feeling better. We looked into this when expecting DS, and you are quite right that the nasal bone thing is a new test, developed by the guy who set up the Fetal Medicine Centre (that's what you meant by FMC isn't it?). But that's because he's one of the leading world experts in fetal testing, rather than because he's some sort of random crackpot.

In your shoes, I would follow their advice re the extra scan and see what you think in the light of that.

Have you thought about what you would do if your odds don't improve? Everybody seeems to say it's a good idea to know before you test, although I don't have personal experience of that.

[Mybox]

An amnio is the only sure way to know the situation. You might need to consider this & agree with isitmeor on thinking things through before your scan. Best wishes.

[thehuntress]

Just a quick update. I had another scan yesterday and the nasal bone was there - bright and clear! It was done by a different sonographer and the baby was a bit more cooperative, so not sure if that made a difference.

So, hopefully this will be reassuring if someone else has this happen in the future. My revised risk is now 1:3172 so I'm really happy with that.

Thanks again for all of the responses.

[TheMightyToosh]

Wow - your risk is really low!

I have a scan and everything looked fine, but with my bloods my risk was 1:260-something. It is still classed as low, but not anything like as low as yours!

Should I be worried? Anyone know of why the bloods might make this big a difference (I'm 34 so the age-related risk was also relatively high.

[thehuntress]

TheMightyToosh - was your combined risk 1:260? I think the way it usually works is that you will have a age-related risk, a nuchal-related risk and a blood-related risk, which they will combine to come up with your number.

So I'm 36, my risk is 1:300s considering just my age. With the low nuchal and bloods, my risk was lowered to 1:3172.

I think if the risk is anything above 1:300, they offer CVS/amnio. But all of this is really individual choice. Risk of miscarriage for CVS/amnio is 1:100, so you have to weigh your risk against that.

There are loads of threads on this topic, so maybe take a look. Sorry, that probably didn't help much.

[TheMightyToosh]

Thanks huntress - yes, it was my combined risk. She said that my bloods were what pushed it up, as the scan was all fine.

They said the threshold they use is 1:250 for high:low divide, so I am officially classed as low. The report said I needed no further tests. But on seeing your result, I'm just wondering why mine is so close to the edge!

BUT - I was officially one day over the time limit (they said the scan was still valid because the baby was within the length measurement) so I'm wondering if this might be why my bloods were a bit higher, because I was further along than I should have been, but would 1 day really make that big a difference??

Will look up the other threads - thanks

[NumptyMum]

TheHuntress - really glad that nose was showing bright and clear! Though as you said, I think it's a fairly new marker - I think possibly it's only the FMC that are looking at the nasal bone - so what you've written may reassure anyone else who now wonders about this.

TheMightyToosh - not sure whether your dates made a difference to your bloods, but scans can also give pointers to problems (or positive things, such as thehuntress just had). Will you be getting a scan later, eg around 18-20wks? As it is, your risk is pretty low, think of it as 259 chances your baby will be fine, vs one that there may be problems. And if there were serious problems, these may well show up on a scan (did in my case, anyway). Hope all goes well.

[TheMightyToosh]

Thank you NumptyMum - that is a great way to look at it

Thanks also Huntress - and sorry for hijacking your thread somewhat! Glad you got the result you wanted in the end