<P> The scan is carried out at 11 -- 13 + 6 weeks pregnancy and assesses the quantity of fluid collecting within the nape of the fetal neck . There are two distinct measurements -- the nuchal translucency , which is measured earlier in pregnancy at the end of the first trimester , and for which there is a lower threshold for increased diameter , and the nuchal fold , which is measured towards the end of the second trimester . The scan may also help confirm both the accuracy of the pregnancy dates and the fetal viability . As nuchal translucency size increases , the chances of a chromosomal abnormality and mortality increase ; 65 % of the largest translucencies ( > 6.5 mm ) are due to chromosomal abnormality , while fatality is 19 % at this size . </P>
<P> The scan is carried out at 11 -- 13 + 6 weeks pregnancy and assesses the quantity of fluid collecting within the nape of the fetal neck . There are two distinct measurements -- the nuchal translucency , which is measured earlier in pregnancy at the end of the first trimester , and for which there is a lower threshold for increased diameter , and the nuchal fold , which is measured towards the end of the second trimester . The scan may also help confirm both the accuracy of the pregnancy dates and the fetal viability . As nuchal translucency size increases , the chances of a chromosomal abnormality and mortality increase ; 65 % of the largest translucencies ( > 6.5 mm ) are due to chromosomal abnormality , while fatality is 19 % at this size . </P>
when can the nuchal fold scan be done
when can the nuchal fold scan be done
11 -- 13 + 6 weeks
11 -- 13 + 6 weeks