The Nuchal scan is carried out at 11 weeks to l3 weeks + 6 days and is a measurement of the amount of fluid at the back of the neck of the fetus.  This measurement, together with a blood test, estimates the risk of the baby having a chromosomal abnormality  such as Down's Syndrome

A full description of this is available in our section Nuchal Scans

This nuchal scan is performed between 11 weeks to l3 weeks + 6 days gestation. A basic anatomy check is performed during the scan with a measurement of fetal size.

All women are at risk of having a baby with Downs' syndrome and all fetus's have a small amount of fluid at the back of their neck, called Nuchal Translucency. Using nuchal scanning we can obtain a measurement of this area. When combined with blood testing, maternal age and accurate gestational age we can assess the individual risk factor for each women. This is NOT diagnostic. It gives us a risk factor.

It gives us a figure in numbers for example 1 : 250 (1 in 250), we would say that this example suggests that there would have to be 250 women, with the same age, gestation and Nuchal Translucency measurement before one women has a baby with Downs' syndrome.