Your doctor may suggest that you have tests during pregnancy to find out if your baby has Down syndrome. You may decide to have:
Screening tests.
These include an ultrasound and a blood test during your first or second trimester. These tests can help show if the developing baby (fetus) is at risk for Down syndrome.
Diagnostic tests.
These include chorionic villus sampling and amniocentesis. They can show if a baby has Down syndrome. You may want to have these tests if you have abnormal results from a screening test or if you are worried about Down syndrome.
Sometimes a baby is diagnosed after birth. A doctor may have a good idea that a baby has Down syndrome based on the way the baby looks and the results of a physical examination. To make sure, the baby’s blood will be tested.