All pregnant women who attend for antenatal care before they are 20 weeks pregnant are offered a screening test for Down's syndrome. This is to assess their chances of having a baby with this condition. Down's syndrome is also called trisomy 21 or T21.
If the screening test shows that the woman has a higher chance of having a baby with Down's syndrome, she'll be offered a diagnostic test to find out for certain if the baby has the condition.
Women can find out more about Down's syndrome on the NHS Inform website. This includes details about the tests on offer.