What happens during a karyotype test?For a karyotype test, your provider will need to take a sample of your cells. The most common ways to get a sample include:A blood test. For this 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.Prenatal testing with amniocentesis or chorionic villus sampling (CVS). Chorionic villi are tiny growths found in the placenta.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.Amniocentesis is usually done between week 15 and 20 of pregnancy.For 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.CVS is usually done between week 10 and 13 of pregnancy.Bone Marrow Aspiration and Biopsy. If you are being tested for or treated for a certain type of cancer or blood disorder, your provider may need to take a sample of your bone marrow. For this test:You'll lie on your side or your stomach, depending on which bone will be used for testing. Most bone marrow tests are taken from the hip bone.The site will be cleaned with an antiseptic.You will get an injection of a numbing solution.Once the area is numb, the health care provider will take the sample.For a bone marrow aspiration, which is usually performed first, the health care provider will insert a needle through the bone and pull out bone marrow fluid and cells. You may feel a sharp but brief pain when the needle is inserted.For a bone marrow biopsy, the health care provider will use a special tool that twists into the bone to take out a sample of bone marrow tissue. You may feel some pressure on the site while the sample is being taken.
