Oscar Nt Scan. The test is performed when the fetus is 11 weeks to 13 weeks 6. Or when your baby measures between 45mm (1.8in) and.
Between 11 weeks and 14 weeks of pregnancy. It is usually done at the same time as your early dating scan and is carried out in the same way. A nuchal translucency (nt) scan is a screening test that is done during pregnancy to measure the thickness of nuchal fold, the fold of skin at the back of a baby’s neck and to assess the amount of fluid build up in it.