Contributed by – Healthians Team
What is the AFP test?
The Alpha-Fetoprotein Test (AFP) test is a screening test that measures the quantity of alpha-fetoprotein in the mother’s blood during pregnancy. The test is commonly done in the second trimester of pregnancy. This is not a diagnostic test. It is often part of the triple screen test that assesses whether further diagnostic testing may be needed or not.
Generally all of us have a very small quantity of alpha-fetoprotein (AFP) in our bodies. Its presence can be higher in the blood in case of a liver ailment, pregnancy and certain forms of cancer. An increased level of AFP in adults who aren’t pregnant hints towards some sort of liver disease.
Who should get the test?
It is a common test for expecting mothers and is done between their 14th and 22nd week. Highly accurate results are received if the test is done between the 16th and 18th week. It is also a part of quad screen which examines the levels of human chorionic gonadotropin (HCG) and estriol, a hormone produced by placenta and baby’s liver, and inhibin A which is also a hormone secreted by the placenta.
Why is the test needed?
This test is used to determine the chances of genetic birth defects in unborn babies. Defects such as neural tube defects, spina bifida and chromosomal aberrations like down syndrome. It helps the medic decide whether further tests are required. It is essential for women who:
- have a family history of birth defects
- are 35 years or above
- had used unsafe medicines during pregnancy
- are suffering from diabetes
It can identify some liver diseases such as cancer, cirrhosis and hepatitis. The types of cancers this test can help detect are as follows:
- testes
- ovaries
- biliary tract
- stomach
- pancreas
What does the test result mean?
An AFP tumor marker test investigates the level of this protein. The average quantity of AFP is generally less than 10 nano grams/milliliter of blood in men and non-pregnant women. High AFP levels during non-pregnancy may point towards some cancers or liver diseases.
Higher than normal results
Above normal AFP levels during pregnancy may result in a neural tube defect in the baby. Their levels differ extensively throughout pregnancy. In most cases raised AFP levels are because of wrong date of pregnancy. The results will be incorrect in case you’ve been pregnant for a longer or shorter duration.
Lower than normal results
Low AFP levels during pregnancy show that the fetus has some chromosomal abnormality such as Down syndrome or Edwards syndrome. Multiple pregnancies like having twins or triplets and fetal death can cause an abnormal AFP reading.
How is the test done?
A maternal serum alpha-fetoprotein test is conducted within the first 4 months of pregnancy, usually between the 14th and 22nd week. It can either be conducted at a doctor’s clinic or in a hospital. In this procedure, the technician takes a blood sample from a vein in your hand or arm. You might experience a small prick with very little bleeding at the pricked spot. This sample is then sent to the lab for clinical testing.
