Maternal Serum Alpha-Fetoprotein (MSAFP) Test: Basic Facts

Maternal Serum Alpha-Fetoprotein Test (MSAFP) is a routine screening test for a mother-to-be. The test aims to check if the unborn baby has a birth defect.

Normally, unborn babies make alpha-fetoprotein (AFP) which shows up in the mother’s blood. By checking the level of AFP of a pregnant mother, the doctor can determine whether the neural tube of the baby grows normally. Later, the neural tube develops into the spinal cord and brain. In often cases, an MSAFP test is often included into a triple screen or quad screen when you are pregnant for about four months.

How is an MSAFP test performed?

In the procedure, the doctor will take a needle to get your blood drawn so that the blood can be examined at a lab. The process is painless and only takes a few minutes. Usually, the blood is drawn from a vein, in your arm or hand. You often need to wait for one to two weeks to get the results.

What do the test results mean?

If women are not pregnant, their AFP level maintains at a low level. If pregnant, their AFP level changes to become high.

In this case, if the test result is negative or normal, it means that the unborn baby is in good health. If the test result shows a higher-than-normal AFP level, the unborn baby may have a neural tube defect. But the test results are affected by many factors such as the mother’s race, weight, having diabetes and so on. So, if the result is positive, further analysis should be made. If the mother-to-be shows an unusually low AFP result, then the mother’s fetus may have a chromosomal abnormality.

But sometimes, even if the AFP level is low, the test results may also be positive. That means the unborn baby may be with Down syndrome or Edwards syndrome.

How many pregnant women have positive results in an MSAFP test?

According to the American Pregnancy Association, results are abnormal for 25 to 50 pregnant women out of every 1,000 pregnant women given an AFP test. However, only between 1 in 16 and 1 in 33 women who have abnormal results will actually have a baby with a birth defect.

If you have abnormal test results, it doesn’t necessarily mean that your child will have a birth defect. It only indicates that more tests are necessary for your doctor to make a diagnosis. Your doctor may perform another AFP test followed by an ultrasound to record images of your unborn child.

Your doctor may order a more invasive test, such as an amniocentesis if your results are still abnormal. In amniocentesis, your doctor uses a needle to withdraw a small amount of amniotic fluid from around the fetus for analysis.

Keywords: Maternal Serum Alpha-Fetoprotein Test; AFP test

* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.