Nuchal Translucency Test Screening in Shrewsbury, Shropshire
The start of pregnancy is both exciting and daunting . ‘Is my baby normal?’ features regularly as one of the questions asked at this stage. The first trimester nuchal translucency test can go a significant way to answer this important question.

Who should have the nuchal translucency test?
All pregnant women should consider having this screening test at the start of their pregnancy as it will help to reassure the vast majority of women that their baby appears to be developing normally. It will also detect at an early stage, those babies that might have a problem. This becomes increasingly important as women get older because their chance of having a baby with a chromosomal condition such as Down’s syndrome will become higher.

When is the nuchal fold screening test carried out?
The test is performed between 11 weeks and 13 weeks 6 days into your pregnancy. It cannot be performed outside this time frame as certain features that need to be seen on the scan are not present. If you are unsure of your period dates or have an irregular cycle, we suggest that you contact your midwife or GP as early as possible to arrange for a dating scan at your local hospital.

What does the test involve?
Using a combination of ultrasound and the measurement of hormones in your blood the risk of your baby having Down’s syndrome can be predicted. The ultrasound scan records your baby’s nuchal translucency measurements, and can also examine your baby in some detail to check whether many of the main organs are developing normally.

What does the scan examine?
The ultrasound scan, sometimes known as the nuchal translucency test, measures the fluid within the skin at the back of the baby’s neck. This is known as the nuchal translucency. This is present within all babies, but the wider the nuchal translucency measures, the higher the change of your baby having Down’s syndrome. Equally the narrower the nuchal translucency measures, the lower the chance.

The nuchal translucency test will also check whether your baby has a visible nasal bone. In the past few years it has been discovered that approximately 3 in 4 babies with Down’s syndrome do not have a visible nasal bone at the time of the first trimester screening test. If the nasal bone is visible at the scan then this will reduce the chance of your baby having Down’s syndrome. Occasionally the nasal bone cannot be seen at 11 weeks as it is too early in the pregnancy. If this is the case and this creates some concern then the scan can be repeated a week later. However if the nasal bone cannot be seen clearly but the nuchal translucency and blood tests are predicting a low risk result it is sometimes not necessary to see the nasal bone in every case.

The nuchal translucency test can also check whether your baby has all its limbs, that the head and brain appear to be developing normally, that the baby has a visible stomach and bladder and the umbilical cord is inserted correctly. From 12 weeks the spine can usually be seen clearly enough to rule out major cases of spina bifida. All of this information will hopefully provide important reassurance.

The scan cannot tell you the sex of the baby as all babies at this stage appear similar. The earliest we could sex the baby with any degree of certainty would be 18 weeks and even then we could not guarantee.

What is the blood test for?
The blood test taken before your scan is used to measure two hormones in your blood. They are both produced by the placenta and are unique to each pregnancy. If the hormone levels are favourable they will reduce the chance of your baby having Down’s syndrome. If they are less favourable they will increase the chance. Adding in the blood test increases the overall accuracy of the test.

Ideally it is better if you can have the blood test at least one day before the scan so that we have the results back when you come for the scan. The overall risk can then be calculated immediately after the scan and the result discussed face to face. If you cannot get the blood test done before the scan it can be taken on the same day but the result will need to be discussed the following day on the telephone.

How is the overall risk calculated?
The starting point for the calculation of risk is your age at the time your baby is due. Thus the older you are then the higher the starting risk of your baby having Down’s syndrome will be. By combining the results of the nuchal fold screening test and the results of the blood test with your risk based upon your age the computer will calculate the overall risk of your baby having Down’s syndrome.

How accurate is the test?
The nuchal fold measurements scan is personally performed by Dr Adam Gornall, Consultant in Fetal Medicine at our premises near Shrewsbury, Shropshire. This means that he has been through a training programme and undergoes regular checks to make sure his scanning technique is accurate. The blood tests are performed at the Fetal Medicine Centre in London which is an accredited laboratory.

The risk that you will be given will not tell you for certain if your baby has Down’s syndrome. However if the overall risk shows that the chance of your baby having Down’s syndrome is in the thousands then the accuracy of the nuchal fold measurements test is very good and most people would feel reassured. If the overall result shows the chance is in the tens, again the accuracy is very good, but there is a significant chance your baby has Down’s syndrome. You may then consider having an invasive test. If you overall risk is around the 1 in 300 region then the detection rate of the test falls and you have to make a difficult decision whether to proceed to a further test or not. Thankfully for the majority of people the test performs in such a way that they are given a clear indication as to which way they should proceed. In other words if your baby does not have Down’s syndrome then the test will almost tell you the answer in around 90% of cases. This is much clearer than using a blood test combined with your age or just relying upon your age as an indicator.

When will I get the results?
We will be able to provide you with your risk result immediately after the scan if you have your blood test performed at least one day prior to the scan. This means that the result can be discussed in detail face to face. This consultation is carried our personally with Dr Adam Gornall who has experience in counselling and will be able to guide you to a decision if you have a result that concerns you. We feel this approach is the most appropriate way of providing you with the result and allows any concerns to be raised at the time of the scan.

What happens if I get a higher risk than I am comfortable with?
Most results will be extremely reassuring and will hopefully allow you to go a long way to answer that important question ‘is my baby normal’. A few results will be ‘borderline’ and will require discussion. Equally a few will be non-reassuring. In that case you may wish to consider an invasive test such as amniocentesis of chorionic villous sampling (CVS).

CVS can be performed after 11 weeks gestation and involves removing a small piece of placental tissue using a needle through the wall of the abdomen. It carries a risk of miscarriage of around 1%.

Amniocentesis can be performed after 15 weeks gestation and involves removing a small amount of amniotic fluid using a needle through the wall of the abdomen. It carries a risk of miscarriage of around 0.5-1.0%.

Both tests can be arranged through the Shrewsbury and Telford Hospitals Maternity Department on the NHS and would always be performed by a Fetal Medicine Specialist. Otherwise it can be arranged through your local Maternity Department if you have come from further a field.

Can increased nuchal fold measurements indicate anything else?
If the nuchal translucency is wider than expected other conditions may be present such as a heart condition. This will be discussed with you further if the thickness is greater than 3mm. In this case it would be recommended that you have a detailed cardiac scan at around 18-20 weeks with a careful review and discussion by consultants experienced in fetal medicine.

A few practical points

How long does the nuchal fold screening test take?
The scan normally takes about 10 to 20 minutes depending upon how clear the picture of the scan and whether your baby is in the correct position. Occasionally you may need to wait around until you baby moves to the correct position. This may mean staying for an extra half an hour.

Can my partner be present?
If you can it is good to share the beginning of the pregnancy with your partner or close family or friends. However the news is not always good so you may need to think carefully whether you wish to bring children. Small children rarely appreciate the scan, and can be quite a distraction to you at a time when you need a clear head. There are toys on hand for small children if you have to bring them along. The examination is always recorded for you so that you can show the family at home later on if they don’t come with you.

When and how do I pay for the test?
The combined test costs £190 which is payable at the time of the blood test. We accept cash, cheque and all major debit and credit cards. If we cannot do the nuchal translucency test for some reason (you are too far on in the pregnancy or the scan shows a miscarriage) then we would make a charge of an early pregnancy scan which is £50. Some medical insurance policies will cover the cost of this screening, but most do not.

What geographical area do you cover?
We are based in Shrewsbury, Shropshire, and our premises are easily accessible from the M54 / A5, so we attract clients from far and wide – but in particular from the West Midlands region, for example from Telford, Wolverhampton, Birmingham, Dudley and Walsall. We also often have clients who travel from Wales to use our services, and indeed from all over the country.