This screening test may be combined with a blood test, for Down’s syndrome and is carried out at 11-14 weeks of pregnancy.

How is it done?

A detailed ultrasound scan measures the thickness of the skin at the back of your baby’s neck. When this measurement is combined with other factors like your age and the number of weeks pregnant you are, an estimate of the risk of your baby having Down’s syndrome can be made.

What will it tell me?

It cannot tell you ‘yes’ or ‘no’ whether your baby has Down’s syndrome, but it can say whether the risk seems to be high or low. If you are estimated to be at high risk, you can choose to have CVS or amniocentesis to find out for sure.

Are there any risks?

None are known.