Nuchal Translucency
Test
What to know
The nuchal translucency test is a safe and simple test performed towards the end of the first trimester of a pregnancy. It comprises a blood test and an ultrasound scan and is likely to detect approximately 85 – 90 percent of chromosomal abnormalities, the most common of which, is Down syndrome or Trisomy 21. Rather than providing any actual diagnosis the test simply groups women as either high or low risk for carrying a baby with a chromosomal or genetic abnormality. Women at a higher risk are then offered further diagnostic tests.
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Is the patient non-english speaking? If so, we can arrange for an interpreter to be present during the appointment. Please let us know as soon as possible so we can make the relevant arrangements.
- Drink 2-3 glasses of water within 30 minutes, commencing 1.5 hours prior to your appointment.
- Please do not go to the toilet
- Continue to take all regular medication as normal
- While the blood test can be performed from 10 weeks on in the pregnancy, the ultrasound portion can only be performed between 12 weeks and 13 weeks and 4 days
- You will be asked for the location and date of the blood test when attending the ultrasound appointment.
- The ultrasound scan is performed in combination with a blood test. The blood test measures the amount of free β-HCG and PAPP-A in the mother’s blood stream and ideally should be performed at about 10 weeks’ gestation
- The nuchal translucency ultrasound is performed between 12 weeks and 13 weeks and 4 days gestation but preferably at 12.5 weeks gestation
- The blood test will need to be organised by your referring doctor
- It is important that he/she gives you a referral for these blood tests and writes on the referral that you are having your nuchal translucency ultrasound performed at Perth Radiological Clinic
- This ensures that the blood tests results are forwarded to our clinic in time for your appointment
- This ultrasound will take around 30 minutes to perform
- In some instances, you may be required to return for further images on another day. This is due to the position of the baby obscuring the sonographers’ views
- The images will then be correlated with the blood test and then reviewed and reported by one of our specialist radiologists
- Due to the complexity of the reporting, this result can take 5 plus business days to be available to your referring doctor.
If your results suggest that your baby is at an increased risk of having a chromosomal abnormality you should discuss this with your referring doctor. The result does not mean that your baby is abnormal but indicates that further investigation may be warranted. In the majority of cases the pregnancy will be normal, but it is important to discuss this with your doctor, who will be able to provide you with information and advice about further testing, for example chorionic villus sampling (CVS) or amniocentesis.
