Finding positive alpha-fetoprotein, or AFP, in the blood can indicate several types of cancer, liver disease or alcohol abuse in a man or nonpregnant woman, according to WebMD. In a pregnant woman, a high level of AFP can indicate a problem with the fetus, the presence of multiple fetuses, an incorrect gestational age or a dead fetus.
AFP is typically not present in nonpregnant adults, states WebMD. Individuals who have AFP in their blood may have liver disease, such as hepatitis or cirrhosis. Patients with testicular, ovarian or liver cancer may also show positive AFP. Several factors can affect the test for AFP. Smoking elevates AFP and so do radioactive tracers used in some medical tests. Patients who underwent a test with radioactive tracers within two weeks of the blood test for AFP may show elevated levels.
Pregnant woman begin to have a rise in AFP during the 14th week of pregnancy, which levels off a month or two before birth and begins declining, explains WebMD. Several factors determine the appropriate level of AFP during pregnancy, such as the mother's height, weight, race and whether she requires insulin for diabetes. An elevated AFP can indicate the fetus has a neural tube defect or may be developing with intestines or other organs outside the body. A low amount of AFP can suggest the fetus has Down syndrome or an incorrect gestational age.