Alpha-fetoprotein levels should be less than 6 nanograms per milliliter in nonpregrant patients, according to Mayo Clinic. Pregnant patients and newborns typically have higher levels of AFP. While no range is available, normal newborns have exhibited AFP levels of over 100,000 nanograms per milliliter.
AFP is a type of protein produced by the liver during early fetal development, states Mayo Clinic. In newborns, levels decline rapidly during the first six months of life. Cancerous tumors of the liver, testes or ovaries and benign liver diseases such as viral hepatitis or cirrhosis can also elevate AFP levels. For this reason, doctors often test AFP levels during the follow-up management of patients undergoing treatment for those cancers.