Alpha-fetoprotein (AFP) test

The AFP test measures how much alpha-fetoprotein is in your blood. Alpha-fetoprotein is a protein made by your liver and the yolk sac of a developing foetus. A small amount remains in your body throughout your life.

Why is the alpha-fetoprotein (AFP) test done?

During pregnancy, the AFP test is used to screen for conditions such as spinal bifida and Down syndrome, check for multiple pregnancies and get an accurate due date. In New Zealand, this test is part of the maternal serum screening programme taken during weeks 14 and 18 of pregnancy.

In other situations, the AFP test can be used to monitor liver disease and test for certain types of cancer, including testicular, liver and brain cancers. It can also be used to monitor cancer treatment and see if cancer has come back after treatment.

No preparation for the test is needed. It is a simple blood sample taken from a vein in your arm.

What are the risks of an AFP test?

There are no risks. However, if you sometimes feel light-headed, faint or bruise easily after blood tests, you may do after this test too.

What do the results of my AFP test mean?

An abnormal result in pregnancy can reveal a multiple pregnancy or a birth defect such as spina bifida, or a genetic disorder such as Down syndrome, foetal death or an inaccurate due date.

In others, the amount of AFP in your blood increases with liver disease and certain types of cancer.

Learn more

The following is further reading that gives you more information on the alpha-fetoprotein (AFP) test. Be aware that websites from other countries may contain information that differs from New Zealand recommendations.

Antenatal screening for Down syndrome and other conditions National Screening Unit, NZ, 2014
Alpha-fetoprotein test Healthline, US, 2017

Credits: Health Navigator Editorial Team. Reviewed By: Gwenda Lawrence, medical laboratory scientist, Auckland Last reviewed: 24 Feb 2020