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Antenatal tests

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People who know about first trimester screening...

3 replies

kickingking · 30/09/2011 20:54

Can anyone please explain the first trimester screening tests to me as I feel I am not bring given a full enough picture by HCPs?

Firstly is the nuchal just to assess the risk of Down's or can other chromosome abnormalities be detected with the NT? And if so, what exactly are these conditions?

Secondly, the serum/blood tests - exactly what can be picked up by this, as well as Down's? I have read that many factors can 'affect' the result, some of which apply to me (being very slim and having T1 diabetes) - but what does that actually mean? Is being light, for example, a real risk factor or does it lead to false positives for some reason?

However, my consultant told me that diabetes does NOT affect results, but I am beginning to suspect she is trying to get me to have the screening when I don't really want to.

I'm really confused. I do understand the the serum screening and the NT don't give a definitive answer - I don't understand what may be picked up aside from Down's and how the risk is calculated.

OP posts:
BedHog · 30/09/2011 23:07

The nuchal test is usually referred to as the downs test because downs syndrome is by far the most common abnormality picked up, but it does also test for other conditions - Pataus, Edwards etc., which as I understand are much more serious conditions than downs.

The accompanying blood tests check the levels of various substances within your blood, which can indicate higher risk of certain abnormalities. Other factors, like age for example, can also affect the result.

Your result will be given as a risk factor - so for example 1:5000 will mean you have a low risk, whereas 1:25 will mean a much higher risk so you would be offered further testing to give you a definite answer as to whether or not your baby is affected.

I haven't heard of being light increasing risk, but if your BMI is below 18 you will probably get extra growth scans in the 3rd trimester, simply because you fit into the same category as 'people who don't look after themselves' (sonographer's words).

cece · 30/09/2011 23:09

There is a charity called ARC that might be able to advise you.

kickingking · 01/10/2011 01:07

My bmi is not as low as 18! I get extra growth scans because I'm diabetic anyway.

All anyone ever talks about with the NT is Down's syndrome. I am more concerned with the other conditions as I understand they are 'incompatible with life' - any idea how reliable the NT is at picking those up?

I did know about ARC, I might give them a ring. All I get from my consultant is 'i just think you should have it done'

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