This test, which is also known as the first trimester screening test, 11-14 test (double test), or nuchal translucency scan, involves ultrasonographic examination performed at 11 to 14 weeks of gestation, and assessing the risk of several fetal anomalies (e.g., Down syndrome) which are identified by laboratory screening tests on mother’s blood sample. After having the test, parents will be explained about the test results in detail.
What is Nuchal Translucency (NT) Scan?
Nuchal translucency is a collection of fluid under the skin at the back of the baby’s neck. It can be measured using ultrasound. Each baby has normally this fluid within certain limits. If an NT measurement gives higher results, this indicates that possibility for both chromosomal and structural disorders is increased.
This ultrasound scan and test is performed to assess the risk for Down syndrome and other chromosomal anomalies; identify structural anomalies that fetus may have at that week; and to diagnose multiple pregnancies such as twin and triplet pregnancies, and asymptomatic pregnancy losses.
The 11-14 scan involves assessing the risk with mother’s age, blood levels of PAPP-A and Free Beta hCG measured for the mother, nuchal thickness of the fetus measured by ultrasound, nasal bone of the fetus, and blood flow in the baby’s heart and ductus venosus. The percentage of identifying the Down syndrome is around 97.5% with all these markers.
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