Triple Screen Test


Tests are now available that go beyond AFP testing in helping your doctor determine if you might be carrying a child with Down syndrome. With this test, your alpha-fetoprotein level is checked along with amounts of human chorionic gonadotropin (HCG) and unconjugated estriol (a form of estrogen produced by the placenta). The levels of these three chemicals in your blood may indicate an increased chance your baby has Down syndrome. For older mothers rate of the problem is better than 60% with a false positive of nearly 25%. If you have an abnormal result with a triple screen test, an ultrasound and amniocentesis may be recommended. An elevated alpha-fetoprotein level can indicate an increased risk of a neural-tube defect (e.g., spina bifida). HCG and estriol are normal in this case. These blood tests are used to detect possible problems. They are screening tests. A diagnostic test will usually confirm any diagnosis.