Nuchal Translucency Ultrasound

A Nuchal Translucency scan may be requested to obtain a numerical risk rating for Down Syndrome. As it is a screening test, it will not tell you definitively if your baby does or does not have Down Syndrome, but will capture 85-90% of fetuses that are at high risk.

Your screening result will combine the following:

  1. Ultrasound measurement of the fluid at the back of babies neck
  2. Your age at the time of the scan
  3. Blood test results (please have your blood test done 1 week prior to your ultrasound if possible)

Your preparation requirements

You will be required to drink 500ml of water finishing one hour prior to your examination. This allows the bladder to fill and helps to visualize the uterus, baby and other structures of the pelvis. Hence, do not go to the toilet once you have commenced drinking the water. If you feel as though you may struggle to hold onto the water, you can come to Sound Radiology prior to your scan to drink the water here.

What to expect

Our ultrasound rooms are dimly lit to reduce the amount of ‘glare’ on our ultrasound monitors. Your partner is welcome to come into the room with you, but as this is a medical diagnostic ultrasound, we do like to limit the number of people who come into the room. If you wish to have more people present, please ask our booking staff when you ring to make your appointment.

You may be asked to change into a patient gown so that we can easily access your abdomen and asked to lie on our ultrasound bed. A warm gel is applied to you which enables us to send the sound waves through the skin to form the image.

A Nuchal Translucency (NT) scan is performed between 11 weeks 1 day and 13 weeks 6 days (and the baby needs to measure greater than 45mm in length and less than 84mm from head to bottom).

Accredited Sonographers must perform your scan to ensure that we get the most accurate results. Here at Sound Radiology our Sonographers are fully accredited or are completing their accreditation process. We have state-of-the-art ultrasound machines that are necessary for achieving the high resolution image of the nuchal translucency.

As we require the baby to be in a certain position for the measurement, your scan can take up to 1 hour to get the best results (2 hours for twins). Uncommonly we may need to proceed to an internal scan (transvaginal scan), or get you to return at another time if the measurement cannot be obtained due to fetal position, you will be asked to empty your bladder for this.

If you are having a Nuchal Translucency ultrasound, please see our checklists below.