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From £205
inc blood test

12 week nuchal scan

11 weeks & 2 days to 14 weeks

At a glance

Looking for a more accurate Down Syndrome test? Want to avoid the risks associated with diagnostic testing? Have you considered the Harmony prenatal test?


The 12 week nuchal scan screens for Down, Edwards’ and Patau Syndromes along with first anatomy checks and measurements of your baby.

  • 95% accurate combined screening
  • No GP referral required
  • Appointment duration twice as long as NHS
  • Blood test to improve accuracy
  • Appointments available at short notice
  • Weekday, Thursday evening or Saturday clinics
  • Convenient central London location
  • Fully accredited and audited clinical staff

You will receive

  • Your results on the day if advanced blood test given
  • Two-page clinical report
  • Complimentary black & white picture (normally £2.50)

What happens with your results?

This is a screening test that will produce a genetic abnormalities risk result, it will not reveal if your baby definitely has a chromosome abnormality.

During your appointment we will go through your report and fully explain our diagnosis and what your calculated risk means.

What does it do?

The nuchal scan provides a screening for chromosomal abnormalities such as Down Syndrome and is combined with a blood test.

It is also the first opportunity to reliably examine your baby’s anatomy as it is fully developed at around 12 weeks.

A nuchal scan will:

  • Check the viability of your pregnancy
  • Confirm the number of babies
  • Take measurements of your baby’s size which will date your pregnancy
  • Screen for Down Syndrome, Edwards and Patau Syndromes

When can I have the nuchal scan?

The nuchal scan can only be performed from 11 weeks and 2 days of pregnancy to 14 weeks and 1 day – with the most accurate time being around 12 weeks. The blood sample can be given any time after 10 weeks of pregnancy.

If you miss this scan you can now have a more accurate screening for Down Syndrome with the Non-invasive Prenatal Test.

Due to the complexity of the nuchal screening, we don’t offer gender identification during this appointment, but you can book a gender identification scan for later in your pregnancy. 

Must I have the screening?

The vast majority of babies are born normal, however all women have a small risk of delivering a baby with a physical disability, and this possibility increases as you get older.

However, if you don’t wish to have the screening, we recommend that you have the early pregnancy scan instead – this will date your pregnancy and check that all is well.

The combined test

The screening is combined with a blood test to increase its efficiency. Adding the blood test result alongside the ultrasound measurements and your age enables us to calculate the risk of your baby having Down Syndrome with up to 95% accuracy.

During the screening we take:

  • An accurate measurement of the thickness of the fluid at the back of your baby’s neck – this is the nuchal area or nuchal translucency.
  • A maternal blood test in which two pregnancy hormones, βHcG and PaPP-A, are analysed.

The results are entered into a Fetal Database and Down’s risk calculation software, which provides the most accurate risk estimation of your baby having a chromosomal abnormality.

A number of major fetal abnormalities including severe forms of spina bifida may be diagnosed at this time too. However, we recommend a detailed fetal anomaly scan at 19-24 weeks for optimal detection of fetal anomalies.

Giving an advanced blood sample

We offer two convenient ways to supply a blood test in advance of your nuchal scan appointment, this will allow you to have the results on the day of your appointment.

  • Visit our clinic any time Monday to Saturday 9am - 6pm at least two days before your scan – there’s no need to book.
  • Request a postal blood pack so you can have the sample taken locally and sent direct to the laboratory – this is ideal if you live or work outside London.

Same day service

Arrive early in the morning to give a blood sample, spend the day at leisure in central London, then attend you nuchal scan appointment in the afternoon or early evening. This allows time for the laboratory to process your results. Please contact us in advance to arrange this service.

When will I get my results?

By giving your blood test in advance of your scan, you will receive your results on the day of your appointment with no anxious waiting for results.

What if I get a high risk result?

If you are not reassured by the final risk estimation or you receive a high predicted risk – a one in 150 risk or lower - you can consider having either a CVS (chorion villus sampling) or amniocentesis test to give you a definite answer.

Providing you have given your blood sample in advance of your nuchal scan appointment you will be able to discuss your options during your appointment with your sonographer or consultant.

Age risk chart

Download a copy of the Down Syndrome age risk chart.

What's my next scan?
20 Week Anomaly scan