AFP Testing (Alphafetoprotein)

Triple Screen, Quad Screen, Penta Screen

Pregnant woman getting her blood drawn
Photo © Glow/Getty Images

Why the test is done:

This test is done to help provide a screening for Neural Tube Defects (NTD) like spina bifida, anencephaly, etc. It has more recently tried to predict the risks of Down Syndrome.

The most frequent reasons for its use are:

  • Screening for certain genetic defects or anomalies
  • Assist in certain genetic testing procedures like Amniocentesis and CVS

How the test is done:

It is a blood test from the mother.

It can be drawn either in a lab, hospital or in the office of your practitioner.

When the test is done:

This test is most sensitive between 15 and 17 weeks of gestation. Accurate dating and assurance of the number of babies ​are very important. Both of these factors can through the results off.

How the results are given:

Test results are usually given in percentages. Examples: Risk of Neural Tube Defect 1 in 500

Risks involved:

There is no risk to the test itself. However, due to the risk of a false positive (meaning baby is said to have a problem but is, in fact, healthy), this test often leads to other more invasive tests that do carry a risk to the pregnancy and baby. These are often used:


Ultrasound screening can also help determine this status with a bit less accuracy. There is also the MaterniT21PLUS blood test. More invasive tests can be used as mentioned above.

Where do you go from here?

Dependent on results.

Other Similar Tests

Some also perform similar tests known as the Penta Screen, Quad Screen, Triple Screen, MSAFP, etc.

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