Alpha-Fetoprotein Unit Converter

Alpha-fetoprotein (AFP) is a glycoprotein that is produced mainly by a developing baby's liver and yolk sac during pregnancy. It is the major protein in fetal blood during the first trimester.

After birth, AFP levels drop rapidly. Healthy children and adults who are not pregnant have very low levels, typically less than 10 ng/mL. In adults, AFP is used primarily as a tumor marker to help detect and monitor certain cancers.

AFP cannot diagnose cancer by itself. Elevated levels can occur with certain cancers, but also with non-cancerous liver conditions. Similarly, some cancers produce normal AFP levels. The test is most useful when combined with imaging studies and other clinical findings.

In fetal development, AFP is produced primarily by the liver, yolk sac, and gastrointestinal tract. In adults, very small amounts are made by the liver, but AFP is re-expressed by certain tumors and regenerating liver cells.