What happens during Down syndrome testing?During a blood test, a health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.For the first trimester ultrasound, a health care provider will move an ultrasound device over your abdomen. The device uses sound waves to look at your unborn baby. Your provider will check for thickness at the back of your baby's neck, which is a sign of Down syndrome.For amniocentesis:You'll lie on your back on an exam table.Your provider will move an ultrasound device over your abdomen. Ultrasound uses sound waves to check the position of your uterus, placenta, and baby.Your provider will insert a thin needle into your abdomen and withdraw a small amount of amniotic fluid.For chorionic villus sampling (CVS):You'll lie on your back on an exam table.Your provider will move an ultrasound device over your abdomen to check the position of your uterus, placenta, and baby.Your provider will collect cells from the placenta in one of two ways: either through your cervix with a thin tube called a catheter, or with a thin needle through your abdomen.For percutaneous umbilical blood sampling (PUBS):You'll lie on your back on an exam table.Your provider will move an ultrasound device over your abdomen to check the position of your uterus, placenta, baby, and umbilical cord.Your provider will insert a thin needle into the umbilical cord and withdraw a small blood sample.
