This is called the dating scan. Its used to see how far along in your pregnancy you are and check your babys development. The scan may also be part of a screening test for Downs syndrome. Your midwife or doctor will book you a dating scan appointment.

How accurate is dating scan?

The earlier the ultrasound is done, the more accurate it is at estimating the babys due date. Ultrasounds performed during the first 12 weeks of pregnancy are generally within 3 - 5 days of accuracy. The most accurate time is between 8 and 11 weeks gestation.