Alpha-Fetoprotein (AFP) Blood Test

Medical Author:
Medical Editor:

What is alpha-fetoprotein (AFP) blood test?

The most widely used biochemical blood test is alpha-fetoprotein (AFP), which is a protein normally made by the immature liver cells in the fetus. At birth, infants have relatively high levels of AFP, which fall to normal adult levels by the first year of life. Also, pregnant women carrying babies with neural tube defects may have high levels of AFP. (A neural tube defect is an abnormal fetal brain or spinal cord that is caused by folic acid deficiency during pregnancy.)

In which situations are high blood levels of AFP seen?

In adults, high blood levels (over 500 nanograms/milliliter) of AFP are seen in only three situations:

  1. Hepatocellular Carcinoma (HCC)
  2. Germ cell tumors (cancer of the testes and ovaries)
  3. Metastatic cancer in the liver (originating in other organs)
Medically Reviewed by a Doctor on 2/13/2014