Advantages of ultrasound nuchal translucency over biochemical screening for Down syndrome include:

Ans. C. Better in multiple gestationThe ultrasound nuchal translucency (NT) is now appreciated as a sensitive marker for Down syndrome and other aneuploidies between 10 and 13 weeks. Outside that range, the NT disappears. Although some centers have had superb results, others have not done well. Blood free -hCG and PAPP-A in the first trimester, and double (AFP and hCG) or triple (AFP, hCG, and estriol at 15 to 20 weeks) evaluations are statistically comparable. The combination of NT and first-trimester biochemistry will likely be the optimal approach. Biochemistry does not work well for multiple gestations. Ultrasound can also detect structural anomalies, but often high-quality ultrasound services require patients to travel long distances, whereas blood can be shipped from essentially anywhere to a competent lab.