Nuchal translucency [NT] is the ultrasound appearance of the fluid behind a baby’s neck. This fluid appearance is present in all fetuses.
During the first trimester screening test, we measure the thickness of this fluid. We follow a very strict procedure in measuring this thickness because, firstly it is a tiny measurement [in millimeter] and secondly, even small changes can have big impact in the final result.
Using the nuchal translucency thickness, we calculate the chance of the baby having Down Syndrome. The lab will combine the value of the NT along with the blood levels of two hormones produced by the baby’s placenta and based on the mother’s age will give a value. This value represents the chance of Down syndrome.
It is important to note that even when the NT is increased, most babies will be normal. There is no need to panic. If the NT is increased, a step by step evaluation of the baby will be advised.