NT Scan in Pregnancy: Screening for Fetal Health

What is Nuchal Translucency?

A nuchal translucency (NT) is an ultrasound test conducted in the first trimester of pregnancy. NT ultrasound is a screening test – and it doesn’t diagnose a condition. The primary objective of this test is to detect if a baby has chromosomal abnormalities or a condition like Down syndrome. The test examines back of your baby’s neck, called the nuchal fold to measure the amount of fluid present. A small amount of fluid is normal and measuring the amount of fluid can help calculate your baby’s chances of having a chromosomal or genetic variant. This test helps your healthcare provider determine if your baby is at risk and if any further tests should be recommended. It can give accurate results if combined with other screening tests during pregnancy.

Purpose of NT scan

The results of the NT scan with higher NT measurement can determine if your baby is likely or unlikely to have any of the below listed conditions:

• Down Syndrome (Trisomy 21)

• Patau Syndrome (Trisomy 13)

• Edwards Syndrome (Trisomy 18)

• Increased risk for congenital heart conditions

When is a Nuchal Translucency Scan Done?

The test is performed when your baby is between 11 and 13 weeks of gestation or when your baby measures 45 to 84 millimetres from crown to rump. This is because fluid behind the baby's neck is reabsorbed after 14 weeks, making it harder to measure later in pregnancy. NT tests are often done as part of a first-trimester screening test.

Test Results

If the screening is abnormal, your healthcare provider might recommend further tests, or a foetal echocardiogram may be suggested to examine the baby's heart closely.