Antenatal Screening

Combined Screening for Down's syndrome & other chromosomal abnormalities: nuchal translucency scan & blood test (low chance)

All pregnant women in England are offered tests for Down’s syndrome. The tests can provide information about the chance of a baby having Down’s syndrome. These tests use blood samples taken from the mother, measurements taken from ultrasound scans (nuchal translucency scan/dating scan) or both to work out this chance.

The NHS Fetal Anomaly Screening Programme recommends that women have the combined screening for Down’s syndrome (blood test and nuchal translucency scan) rather than just the blood test or the nuchal translucency scan on its own. The vast majority of units in England, Scotland and Wales now offer combined screening for Down’s syndrome.

Nuchal translucency scans (ultrasound) are normally done between 10- 14 weeks of pregnancy. They measure a small fluid collection within the skin at the back of the baby's neck (nuchal translucency) to help identify the chance of Down's syndrome and other conditions. The results are combined with a blood test result (combined screening test) to give a more accurate calculation but these tests cannot give a definite diagnosis.

If the chance is more than 1 in 150, further tests for Down's syndrome will be offered. If the measurement of the fluid is the same or greater than 3.5mm, women will be advised that this may be an indicator of heart or other problems and a referral to fetal medicine specialists will be offered.

The chance of a baby having Down's syndrome increases as the mother gets older. The combined screening test assesses your individual probability, and can show whether it is higher or lower than for other women of the same age.

Not everyone we talked to had a nuchal scan. Sometimes it was not offered locally on the NHS, and some people decided they did not want to pay for it privately, particularly if they felt they had a lower chance of their baby having a condition.

One woman chose not to pay privately because she did not get much information until her booking visit and did not feel she really wanted it. (See also 'Information for making decisions about antenatal screening').

Nuchal scans were not available on the NHS locally and she did not feel the need to have one privately.

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Nuchal scans were not available on the NHS locally and she did not feel the need to have one privately.

Age at interview: 33
Sex: Female
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It's not offered in this health area. It's offered in both regions to either side but it's not offered here.

So if you'd wanted it you would have had to pay for it?

Yeah.

And they didn't tell you that it was available if you paid for it?

No. They did tell me, the midwife told me at my booking-in clinic that, because we only get one scan unless there's reasons for others, which was at 11 weeks. So she did, she told me that I could actually go and get a private scan done later on if I wanted to'.

Did you think about going for it privately?

No, actually - well, I mean, I could have. I could have, I'm sure if I'd pushed with my GP I could have been sent to, you know, one of the regions close by, to be honest. But because of the timing of it, you know, I didn't really think any more of it because I'd been, you know, gone for my booking visit and that was when I got all the information about it. So, and I mean I had heard things being mentioned about it, but I hadn't actually looked into it at any great detail so I didn't really think about going privately.

Do you wish you'd known about it earlier?

Possibly, I don't know. I mean I'm going for my AFP will be done this week. And I think myself and my husband have talked about it, you know, at quite great length and I don't know that it will actually influence our decision of what we would do anyway. 

So part of me thinks it's good to be screened but I don't know that it would actually make any difference to the decision I made or that we made. I don't think we would actually go down the line of termination.
 

Some people were unsure whether they’d had a nuchal scan or just a dating scan. Many were unaware they could have a blood test at the same time. Some commented that the process seemed very rushed, even if they were well-informed. Two people said that they had made their appointment too late for the scan measurements to be reliable.

For women who book too late (after 14 weeks +1 day), for a combined test (blood test and nuchal translucency scan), the quadruple test is offered. (See ‘Blood test screening’ for more information).

She had the combined nuchal scan and blood test privately, but found out only just in time that it was available.

She had the combined nuchal scan and blood test privately, but found out only just in time that it was available.

Age at interview: 35
Sex: Female
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At my first booking visit the midwife was very good and explained very clearly about the options available to me. And she explained that I could have a primark blood test in conjunction with a nuchal scan and I decided that - I hadn't heard about that before - but I decided that was definitely the option I wanted to go for, because you find out much earlier in the pregnancy if there are any problems.

So you had to pay for that?

I had to pay for that.

And what was the experience of having that scan like?

It was actually quite rushed in terms of getting it, getting all the different stages done in time. I'm, you know, I'm pleased that she told me about it then, because I could otherwise have missed the window of opportunity. 

Almost straight away I had to phone up the centre that do the test, the blood test. They have to send you a sample bottle. You then have to arrange an appointment with your GP nurse to get a blood sample, and send it back to them. And in fact I actually found it quite difficult just to get an appointment with my nurse, so it was all rather tight in terms of time.
 

For most women who had the nuchal scan, like other scans, it was an enjoyable experience. Many were impressed at how staff took time to explain what they were seeing on the screen and answered questions. The scan gave them their first chance to see the baby, and made pregnancy seem real. This woman also commented on the high quality of the equipment used for nuchal scans at specialist centres. Some women mentioned the discomfort of waiting with a full bladder, and staff pressing uncomfortably hard as they do the scan.

They were impressed by the professionalism of staff carrying out their nuchal scan and felt well informed and reassured.

They were impressed by the professionalism of staff carrying out their nuchal scan and felt well informed and reassured.

Age at interview: 37
Sex: Female
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The people who performed the scans were obviously very professional and experienced. We asked questions and they answered everything we wanted to know. There was no interruptions or problems.

The experience was excellent, very straightforward, we had a good feeling afterwards, we felt very reassured with the whole thing, so it's not that I have doubts that, oh, they were, you know, perhaps they didn't know what they were doing.
 

Seeing her baby during the nuchal scan was a wonderful experience which made pregnancy seem real.

Seeing her baby during the nuchal scan was a wonderful experience which made pregnancy seem real.

Age at interview: 33
Sex: Female
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I was, I mean the first time I clapped eyes on my first child I just couldn't believe it, how baby-like and how detailed. I mean that nuchal fetal, that's the best scan you get. All the other scans - I mean, the local hospital scans were very crummy resolution - are just awful. 

It's the best scan, I think, that you really see your baby. I mean, a) it's the first one. Oh, I mean, also I'd been told drink a lot of fluid beforehand, and when she looked at it the first time, the very first scan I had, she was just seeing fluid and fluid and fluid, because I hadn't gone to the loo. I was busting and I'd drunk, like it said on the literature, I'd drunk two litres or whatever, two pints, a litre. 

And she - I thought, 'Oh, maybe it's a phantom pregnancy. Maybe it's not really there, you know. Maybe it's just my hormones, you know.' And you know, it happens.  And then when she'd actually found it, 'Oh okay. I am pregnant. This isn't just a phantom issue, you know.'  

So that was just a bit of relief, really, just to see, to see him there, you know, see he really existed and was happening. And no, I did enjoy it. It was lovely to see both. No, definitely, it was still lovely to see them. I did have this issue I was trying to hold myself back a bit emotionally from getting too carried away until I got the all clear. But I definitely still enjoyed my first sight of them.

In most cases, people were reassured by their results (see also 'Understanding antenatal screening test results'), but some felt anxious during the scan itself. Reasons for worrying included:

  • Staff talking to each other, not to the parents
  • Calling in a senior colleague without explaining why
  • Staff seeming rushed or detached
  • Having to have a repeat scan
  • Staff keeping or becoming silent without explaining why.

Seeing her baby during the nuchal scan was wonderful but it was alarming that staff talked to each other, not to her.

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Seeing her baby during the nuchal scan was wonderful but it was alarming that staff talked to each other, not to her.

Age at interview: 36
Sex: Female
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And what was the experience like?

From what I recall about it, it was, it seemed to go on for quite some time. It felt like it was very detailed. There were also two doctors doing it, and I think one was learning, so we were sort of in a teaching environment, which was fine, I felt OK with that.  

I can't remember whether we were asked whether that was all right or not actually. I think it was kind of assumed that it would be OK that, you know, I'd be scanned and there'd be these two doctors talking about what they could see on the screen in a sort of a removed way. And also sort of calling a senior colleague in when they weren't quite sure what was what. So that was a bit alarming, at some stages. 

Did they find anything?

No. I think it was more about accuracy. I think they were more concerned about actual measurements. And they had a few concerns about the technicalities of the equipment. Which was all very well and good, but you know, this was the first time that we were going to see a picture of our baby and it did take a little bit of just taking a deep breath and kind of try to go with the flow of the situation, really.

What was wonderful about it was obviously seeing, you know, our baby. But also we got to hear the heartbeat for the first time and that was actually quite overwhelming. And very, very special actually. So it was a bit of a mixed experience. 

How do you think they should have handled it?

Hmm, I think they perhaps should have just introduced the fact that they, you know, that somebody was learning, and not assumed - you know, I think there was just an assumption that, 'Oh, here's the next group of people coming in and oh, they'll just know that we're teaching here.'  

So I think that would have just, you know, that would have just made the situation fine. But because they didn't explain and because they didn't say that, you know, they might actually be talking amongst themselves and it didn't necessarily mean that there was anything wrong, I think that that could have just smoothed things over a little bit from the start.
 

In her second pregnancy, she was anxious that the sonographer doing the nuchal scan seemed rushed. She needed more reassurance.

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In her second pregnancy, she was anxious that the sonographer doing the nuchal scan seemed rushed. She needed more reassurance.

Age at interview: 36
Sex: Female
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I know the second time round the nuchal was done at the other, not the local hospital and very different actually, very different, in the sense that it was done much quicker, and that was because there was no teaching situation going on.

The scanner was very rushed - I felt she was very rushed. And there was, obviously they'd had some hiccup administratively in the day because all these women had turned up and the list should have been cancelled. And there was all sorts of things happening. And so she was stressed out, and I was very much aware of that, and I just thought I just hope you're doing your measurements properly. 

So I just had to keep calm about that and just try and relax. But, you know, she did it, and it was just done, it was just much more, 'Oh, I've done this before, so I know what it's about, so let's just see what the test comes back as.' And as it turned out, again it came back as low risk, but because I'm a year older of course the adjusted risk is going to be slightly different.  

And I needed a bit more reassurance that it was still OK. I do remember that. But she was OK about that. She did take the time out to explain that there was no action that she would have, you know, that she would have recommended, so that was OK.
 

Most people said they preferred to be talked to throughout the scan and have everything explained. (however sometimes the person doing the scan may not feel qualified to discuss the results). A woman carrying twins described different levels of communication in two repeat scans and their effect on her.

In two repeat nuchal scans, she felt the consultant was much more communicative than the first person who scanned her.

In two repeat nuchal scans, she felt the consultant was much more communicative than the first person who scanned her.

Age at interview: 38
Sex: Female
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So when you came to what must have been your fourth scan by this point, it was all sorted out?

Yes. We, I saw the consultant and we had, it was quite a contrast actually, because first of all there was a, I don't know, I think it was a doctor, who did the scan, who had a manner of doing it which was just to sit there sort of silently looking at everything and recording all the information. And the information would be passed on to someone else who was writing it down, it was a nurse or a midwife. 

And that was very, quite anxiety-making, because we didn't know what was going on and we did ask, 'What's your measure? What does that measure?', and she'd say, 'It measures the circumference of the head', and they were looking and this and they were looking at that. But we had to ask her and, so she wasn't forthcoming at all in terms of what she thought until she got right to the end when she said, 'I think everything's fine'. But by which stage we didn't believe her because, oh, you know, she hadn't explained anything. 

And then, what happened then was the consultant came in, and he went through the whole process again but in a completely different way, which was to describe everything that he saw. And first of all, without going, he just looked at where the babies were lying, where they were and described them. 

Then every measurement he did he would say what it was and say, 'That's absolutely fine and there's nothing wrong with the baby'. And his way of dealing with the fact that one of them was curled up, the one was, he was still curled up, was I was lying on the bed and [name], my partner, was sitting on a chair. And he said, 'Well, you're lying down and he's sitting up, what's the big deal?' And basically that's what the babies were like.  

The little girl one was lying flat and she could be easily measured, and the other one was like that with his legs over his head. But he said that it was absolutely fine. So his method of explaining what was going on was really substantially better than how the first doctor had done it, and he was really excellent, because you knew exactly what he was seeing, and he was telling you whether there was anything problematic about that and saying that there wasn't. And that was excellent, he was really good.

Had they forewarned you that somebody would come in again and do the whole thing through from scratch?

No, that was really nerve-wracking in that, especially because of how she'd been, and I think I said, 'Why, are you getting the consultant? Did you have to get the consultant in?', or something like that. And she said, 'Oh no, he was going to do it anyway. He was always going to look at the results'. 

But they hadn't explained that, so he just kind of appeared from nowhere. And that, having not felt very confident about what had happened so far, that was even more alarming, that they then thought, 'Oh, she needs to get the consultant in.' But in fact he was, he was so good that very shortly after, you know, you began to feel reassured. 

And he just had a very much more open and it, just more forthcoming in terms of what was going on and what he was doing, and he had a good way of explaining what he was doing, putting you at ease. He was very good.
 

One person felt she would probably rather receive bad news after the scan than during it. The importance of human warmth was emphasised by a woman who trained as a doctor, as a message for all professionals communicating with pregnant women, in scans and in other settings.

The sonographer was quiet during her nuchal scan. She would rather wait till after the scan to receive bad news.

The sonographer was quiet during her nuchal scan. She would rather wait till after the scan to receive bad news.

Age at interview: 35
Sex: Female
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The scan was sort of quite detailed and they spend some time over it. And then they phone up there and then on the spot to get your blood test results, to the centre where the blood test result is being done, because they're separate. They were separate venues.

And then they're very quiet throughout the whole process. They don't sort of give you any hints as to whether things are good or bad, and then they take you to a little room afterwards and give you a piece of paper which shows you your risk. And I think for my age, which is, will be thirty five when my baby's born, it's about one in four hundred is the sort of national average. And she came back with a piece of paper saying that mine was one in eleven thousand, which felt very reassuring.

What was it like during the scan then, given this silence? Was that worrying?

I mean they pointed out sort of features on the baby, but they didn't give any hint as to whether there were sort of things wrong or not.

Would you have liked them to?

I'm not sure. Possibly. I suppose if it had been good news it would have been nice if they were saying as they were going along, "Well, that looks fine, that looks fine". If it had been bad news I'd probably rather not have known in that position, I'd probably rather be sitting in a room, and sort of take it on board then. But yes, thinking about it, it would have been reassuring if they'd said, "Oh, that looks, that looks good, that looks OK."
 

She felt it was important for health staff to imagine themselves in the patient's place and remember to show human warmth.

She felt it was important for health staff to imagine themselves in the patient's place and remember to show human warmth.

Age at interview: 37
Sex: Female
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We do tend to get so involved with what we are doing because there is so much to do, that you forget about the person, the person you are attending. And so, you know, the specialist in eyes says, 'This is an eye' and he doesn't see the rest of the person, and that's for all the specialities. 

I think it's very, very, very important for everybody who works in health care, whatever you do, to always remember that you have a person there, and that, you know,  the fact that you know a bit more in that particular area doesn't make you superior or better to that other person. 

And you yourself one day will be in that person's place, because one day you will be a patient, one way or another. So I think we should always keep in mind that, and try to, before putting all the science in practice and all the knowledge, put the humanity, yeah? 

And that's what I try to do in everything I do, because I think it's very important to, you know, show some warmth, human feeling to others - and it usually works. So, especially, you know, in the pregnancy experience, which is something so human, so common, so everyday, and which should be always an issue of happiness, and, you know, expectations and optimism. 

Yes, healthcare professionals can do a lot just by, you know - I think they do it great here, I am not criticising. I think from what I have seen, people are really great. Nurses and midwives and doctors, they usually are very good. 

It is just that sometimes, perhaps for over work, overload of work, or problems of limitations of funds, or whatever, they tend to, you know, be a bit stressed and forget a bit that, you know, that's not only one patient in front of the long queue but a person. So it would be nice to remind them a bit and to make that experience even better.
 

Some people who were reassured by their nuchal scan results later found their baby did have a chromosomal condition, and some people were told they did have an increased chance of something being wrong with the baby.

(See also 'Combined screening for Down's syndrome and other chromosomal abnormalities: nucal scan and blood tests (being told something may be wrong)', 'Understanding antenatal screening test results', 'Deciding whether to have further diagnostic tests' and 'Learning after birth that the baby has a condition').

Many experiences discussed here are common to other types of scan. (See also 'Early dating scans' and '18-20 week scans' ).

Last reviewed July 2017.
Last updated July 2017.

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