Screening for Sickle Cell Disease
The purpose of screening is early diagnosis and treatment. Screening tests are usually given to people without symptoms currently, but who may be at high risk for certain diseases or conditions.
The same tests used to diagnose sickle cell disease can be used to screen for it before symptoms begin. These tests include:
—A small blood sample is taken and sent to a laboratory, where the percentage of normal and abnormal hemoglobin is measured.
—A small blood sample is taken and sent to a laboratory. In the laboratory, a substance called a deoxygenating agent is added to the blood sample. If the deoxygenating agent causes at least 25% of the red blood cells to assume a sickle shape, the test is considered positive for the presence of either sickle cell trait or sickle cell disease. Hemoglobin electrophoresis will need to be done to distinguish between sickle cell trait and sickle cell disease.
—In this test, ultrasound is used to locate the fetus and a pocket of the fluid that surrounds the growing fetus. A long, thin needle is used to remove a small amount of amniotic fluid, which is sent to a laboratory for testing.
In many hospitals, screening tests are done on newborn babies before they leave the hospital. Screening tests may also be done on adults who want to know whether they carry the sickle cell trait. Pregnant women can also choose to have their unborn babies tested for the presence of sickle cell trait or disease.
Sickle cell disease. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed. Updated June 6, 2013. Accessed July 1, 2013.
Sickle cell disease. Nemours' KidsHealth.org website. Available at:
http://kidshealth.org/parent/medical/heart/sickle%5Fcell%5Fanemia.html. Updated September 2012. Accessed July 1, 2013.
Sickle cell disease (SCD). Centers for Disease Control and Prevention website. Available at:
http://www.cdc.gov/ncbddd/sicklecell/index.html. Updated September 27, 2012. Accessed July 1, 2013.
What is sickle cell anemia?
National Heart, Lung, and Blood Institute
website. Available at:
Updated September 28, 2012. Accessed July 1, 2013.