What is a Maternal Blood Screening Test?
• Maternal Blood Screening tests are performed during a pregnancy at specific gestational ages. • Depending on the test used, it tells the likelihood that a pregnancy may be affected with a disorder, such as Down syndrome, Trisomy 18 or an open neural tube defect. It does not determine if the pregnancy is actually affected with these disorders. • It sometimes predicts a “high risk” for a pregnancy to be affected with one of these conditions, even when the pregnancy is not affected. • It leads to the detection of about 80% to 90% of pregnancies with these three conditions, depending on the particular screening test used and the gestational age of the pregnancy. Therefore, approximately 10% to 20% of pregnancies with these conditions are missed by screening. • It does not provide any information about other genetic conditions. • It is not associated with a risk of miscarriage. Common examples of screening options include: 1. First trimester screening: This test screens for pregnancies at
