Nuchal translucency score

[lozster]

I had my dating/ nuchal scan yesterday at 13 + 1. It's the combined test so they took some blood and told me that if the result was worse than 1:150 someone would call me in the next 2 weeks. However, the sonographer said the nuchal measurement was 'normal' which, given my worry about screening and the fact I am 40 and pregnant after many years fertility treatment, was news gladly received. I've now checked my notes and can see that the measurement is 3mm. Stupidly (?) I googled normal nuchal ranges and can see that different hospitals have different cut offs. There are many threads I can see of women being classed as high risk based on scores way lower than mine. So now I am worried. I wondered whether the measurement has to be interpreted in the context of the baby's length/ the fact I was 13 + 1?

This is such a roller coaster . Feel like i am destined to have an amnio. At the same time i am equally concerned about NOT being called as i will then need to wait until my next mid wife appointment to get the actual result which could end up being very close to the cut off anyway. The cut off of 1:150 also seems to vary from place to place - in other areas I have read it is 1:200 or even 1:250 Can any one advise?

(Btw I have read the harmony threads but am already struggling with time off work, am very far away from London and its £7/850!)

[sleepyhead]

Yes, the measurement has to be taken in context with gestational age. So 3mm at 13+1 is "lower risk" than at 11+1 etc.

The formulas that they use to calculate risk are complex and really not something that you can second guess from one measurement and the Internet , the same goes with arbitrary cut offs for "high risk".

I quite like that my hospital has stopped using the term low/high risk and now just talks about results that suggest further testing might be warranted (although of course it means the same thing).

I found it helpful (and I did come back "high", 1:27) to try to think about what 1:150 or 1:250 or 1:50 etc would look like in real life, eg a room of 150 people. I think we find it very hard to properly quantify risk in a meaningful way.

It might be worth thinking about what sort of figure you would personally be happy with (I know, hopefully it'll be 1:20000, but what's the lowest that would feel like a negligible/manageable risk to you, bearing in mind that further testing is not risk free). For me it was 1:50 and so I did have further testing. All was well. I hope you get the result you want and enjoy the rest of your pregnancy

[lozster]

Sleepyhead - thanks so much for the reply, it means a lot to me. That's the good side to the Internet.

I totally agree with having a figure in mind. I do but OH doesn't. I'm not helping here as I see myself as being in the last chance saloon of the last chance saloon. Because of my age and tortuous route to pregnancy I feel terrified by everything to do with the health of the baby. I haven't even told anyone about it yet. I allow myself the odd day dream of what the nursery could look like and that's it, I go back to a mind set of I 'might' be having a baby, not that I am.

[massagegirl]

I don't know if it will make you feel better but my nuchal was 3.9 so above the cut off 3.5 at my hospital. Combined with bloods and age my risk was 1:12. No chromosome problems found, I had an amnio.