Nuchal dating scan

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What is this information about?

This information is about your nuchal dating pregnancy scan. It explains:

• why you are having this scan
• what you need to know before your scan
• what we look at in this type of scan
• what happens after your scan.

Why I have I been given this information?

You have been given this information because you have chosen to have the combined screening test. This information will help make sure that you are prepared for your scan and that we get the best information possible about you and your baby. This will help us care for you during your pregnancy, delivery (when your baby is born) and postnatally (after your baby is born).

Why am I having a nuchal dating scan?

A nuchal dating scan is done as part of the combined screening test. The combined screening test checks the chance of your baby having Down’s Syndrome, Edward’s Syndrome and Patau’s Syndrome. 

 If your baby has one of these conditions, it will mean that they develop differently. You should receive information about these conditions from your midwife, at your antenatal booking appointment. If you would like to find out more about these conditions, please check the NHS website Screening for Down’s syndrome, Edwards’ syndrome and Patau’s syndrome – NHS (www.nhs.uk).

What measurements of my baby will the sonographer do at the nuchal dating scan?

• the sonographer will measure your baby from their head to their bottom. This measurement is called a Crown Rump Length (CRL) and is used to work out your estimated due date (EDD).
• the sonographer will measure an area of fluid at the back of your baby’s neck. This area of fluid is called the nuchal translucency (NT).

Once we have got good measurements of your baby’s CRL and NT, you will need to go for a blood test in the antenatal clinic. Your CRL, NT and blood test results will be combined to work out the chance that your baby is affected by any of the conditions that we are checking for (Down’s syndrome, Edwards’ syndrome and Patau’s syndrome).

Which parts of my baby’s body will be checked at the nuchal dating scan?

We will check parts of your baby’s body, to make sure your baby is developing as expected. These checks look at your baby’s:

• head and brain
• tummy (stomach, bladder and abdominal wall)
• arms and legs.

What else will the sonographer be checking for at my nuchal dating scan?

We will also check your placenta and the ‘water’ around your baby (amniotic fluid). We will look around your womb and try to check your ovaries.

When in my pregnancy will I be able to have my nuchal dating scan?

We can offer you your nuchal dating scan when you are between 11 weeks and two days and 14 weeks and one day pregnant.

Your midwife should arrange your scan after your booking appointment. The scan date will be based on your last period date (LMP). If you do not think that you will be between 11 weeks and two days and 14 weeks and one day pregnant at the time of your scan, please contact the ultrasound booking team. They may ask you some questions to help make sure we scan you at the right time.

What happens after my scan?

• For most people, the sonographer will explain the results of your scan to you.
• We will give you a printed copy of the results (scan report) and a copy will also be uploaded to your Badgernotes (your electronic pregnancy notes).
• If you do not understand the results or if you have any questions or concerns, do ask your sonographer at the time of your scan.
• We will book in your other scans at the correct times based on your dating scan.

What happens if there are unexpected findings at my scan, which show that there be concerns for the health of me or my baby?

• If there is anything on the scan which does not look as we would expect, your sonographer will tell you.
• If we are not sure about anything on your scan you may see someone from our ‘Screening team’ this could be a specialist midwife or doctor who will give you more information after the scan.
• Sometimes we need to arrange more detailed scans, scan later in the pregnancy or do extra tests before we can get any extra information about you or your baby.
• These extra scans or tests may be at different hospitals.
• For some people, unexpected findings come back with no problems once a specialist has had a closer look.

How can I find out more about preparing for my scan?

Who should I contact if I need further information about my nuchal dating scan or support after I have read this information?