Ultrasound Level I NT/NB Scan (For 11-14 Weeks Pregnancies) scan is an ultrasound done between the 11th and 14th weeks of pregnancy. This test measures the nuchal fold thickness which is an area of tissue at the back of an unborn baby’s neck.
The cut-off for the nuchal translucency measurement is 3.5 mm. If your measurement is less than 3.5 mm, this is considered “normal”. If your measurement is 3.5 mm or more, this is considered “increased”. The ultrasound also looks at the baby’s body parts, like the heart and the brain.