Ultrasound is a scan that uses high frequency sound waves to study internal body structures. The sound waves are emitted from a vibrating crystal in a handheld scanner. The reflected sound waves or ‘echoes’ are then translated into a grainy, two-dimensional (or sometimes three-dimensional) image on a monitor.
Ultrasound is used during pregnancy to check the baby’s development and to help pick up any abnormalities such as Down syndrome. Since the procedure can’t produce high quality images, any suspected abnormalities need to be confirmed with other tests. The ultrasound scan isn’t 100 per cent accurate, but the advantages of the test are that it’s non-invasive, painless and safe for both mother and unborn baby.