Nuchal Translucency sreening (NT Scan) – This is an optional scan which is recommended by Gynecologists in the US to test for presence of Down syndrome, chromosomal abnormalities or congenital problems in the baby. This is usually recommended between 11th -14th weeks of pregnancy. It is mandatory screening if mother is above 35 years of age.
This screening involves (1) Ultrasound – where they measure the thickness of baby’s neck. Since the baby’s neck is still transparent, they can check for presence of fluid at the back of the neck, which enlarges the clear space in babies with down syndrome. Normal recommended measurement is between 1mm-3mm. Anything measuring above 3mm is treated as indicator of Down syndrome and the risk range is assessed based on maternal age and is provided to the parents. (2) Blood work. The results from ultrasound and blood work is combined and the presence or absence of Down syndrome in the baby is determined. They perform another blood test between 16th – 21st week of pregnancy to confirm the results.
More details about NT Scan can be found here: http://www.babycenter.com/0_nuchal-translucency-screening_118.bc?page=1
Even though NT Scan wasn’t mandatory for us, we opted for it and scheduled it on Feb 25th,2015. Fortunately, my ultrasound and blood work came back normal. My baby’s neck thickness measured 1.3 mm and was in normal range.