Alpha fetoprotein

定义

Alpha fetoprotein (AFP) is a protein produced by the liver and yolk sac of a developing baby during pregnancy. AFP levels go down soon after birth. It is likely that AFP has no normal function in adults.

A test can be done to measure the amount of AFP in your blood.

Alternative Names

Fetal alpha globulin; AFP

How the Test is Performed

A blood sample is needed. Most of the time, blood is typically drawn from a vein located on the inside of the elbow or the back of the hand.

How to Prepare for the Test

You do not need to take any special steps to prepare.

How the Test will Feel

You may feel slight pain or a sting when the needle is inserted. You may also feel some throbbing at the site after the blood is drawn.

Why the Test is Performed

Your health care provider may order this test to:

• Screen for problems in the baby during pregnancy. (The test is done as part of a larger set of blood tests called 四屏幕.)
• Diagnose certain liver disorders.
• Screen for and monitor some cancers.

正常的结果

The normal values in males or nonpregnant females is generally less than 40 micrograms/liter.

The examples above are common measurements for results of these tests. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test results.

What Abnormal Results Mean

Greater than normal levels of AFP may be due to:

• 癌症 in 睾丸, ovaries, biliary (liver secretion) tract, stomach, or pancreas
• Cirrhosis of the liver
• 肝癌
• Malignant teratoma
• Recovery from hepatitis
• Problems during pregnancy

参考文献

Driscoll DA, Simpson JL. Genetic screening and diagnosis. In: Landon MB, Galan HL, Jauniaux ERM, et al, eds. Gabbe's Obstetrics: Normal and Problem Pregnancies. 8日艾德. Philadelphia, PA: Elsevier; 2021:chap 10.

Carter N, Sharpless Chalk B. 新生儿学. In: Kleinman K, Mcdaniel L, Molloy M, eds. The Harriet Lane Handbook. 22日艾德. Philadelphia, PA: Elsevier; 2021:chap 18.

Lee P, Jain S, Pincus MR, et al. Diagnosis and management of cancer using serologic and other body fluid markers. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24日艾德. Philadelphia, PA: Elsevier; 2022:chap 76.

Wapner RJ, Dugoff L. Prenatal diagnosis of congenital disorders. In: Resnik R, Lockwood CJ, Moore TR, Greene MF, Copel JA, Silver RM, eds. Creasy and Resnik's Maternal-Fetal Medicine: Principles and Practice. 8日艾德. Philadelphia, PA: Elsevier; 2019:chap 32.