Health Guide

MS alpha-fetoprotein level

What is this test?

This test measures the level of alpha-fetoprotein of a mother's blood during pregnancy. This test is used to evaluate pregnancy complications. This test may also be used to screen for possible birth defects[1][2][3][4][5][6][7][8][9].

What are other names for this test?

  • Maternal serum (MS) alpha-fetoprotein level
  • Maternal serum alpha fetoprotein level
  • Maternal serum alpha-fetoprotein level
  • MSAFP level

What are related tests?

  • Chorionic gonadotropin, beta-subunit measurement
  • Inhibin A measurement
  • Unconjugated estriol measurement

Why do I need this test?

Laboratory tests may be done for many reasons. Tests are performed for routine health screenings or if a disease or toxicity is suspected. Lab tests may be used to determine if a medical condition is improving or worsening. Lab tests may also be used to measure the success or failure of a medication or treatment plan. Lab tests may be ordered for professional or legal reasons. You may need this test if you have:

  • Birth defect
  • Down syndrome

When and how often should I have this test?

When and how often laboratory tests are done may depend on many factors. The timing of laboratory tests may rely on the results or completion of other tests, procedures, or treatments. Lab tests may be performed immediately in an emergency, or tests may be delayed as a condition is treated or monitored. A test may be suggested or become necessary when certain signs or symptoms appear.

Due to changes in the way your body naturally functions through the course of a day, lab tests may need to be performed at a certain time of day. If you have prepared for a test by changing your food or fluid intake, lab tests may be timed in accordance with those changes. Timing of tests may be based on increased and decreased levels of medications, drugs or other substances in the body.

The age or gender of the person being tested may affect when and how often a lab test is required. Chronic or progressive conditions may need ongoing monitoring through the use of lab tests. Conditions that worsen and improve may also need frequent monitoring. Certain tests may be repeated to obtain a series of results, or tests may need to be repeated to confirm or disprove results. Timing and frequency of lab tests may vary if they are performed for professional or legal reasons.

How should I get ready for the test?

Before having blood collected, tell the person drawing your blood if you are allergic to latex. Tell the healthcare worker if you have a medical condition or are using a medication or supplement that causes excessive bleeding. Also tell the healthcare worker if you have felt nauseated, lightheaded, or have fainted while having blood drawn in the past.

How is the test done?

Laboratory test results may vary depending on your age, gender, health history, the method used for the test, and many other factors. If your results are different from the results suggested below, this may not mean that you have a disease. Contact your healthcare worker if you have any questions. The following are considered to be normal results for this test:

How will the test feel?

The amount of discomfort you feel will depend on many factors, including your sensitivity to pain. Communicate how you are feeling with the person doing the test. Inform the person doing the test if you feel that you cannot continue with the test.

During a blood draw, you may feel mild discomfort at the location where the blood sample is being collected.

What should I do after the test?

After a blood sample is collected from your vein, a bandage, cotton ball, or gauze may be placed on the area where the needle was inserted. You may be asked to apply pressure to the area. Avoid strenuous exercise immediately after your blood draw. Contact your healthcare worker if you feel pain or see redness, swelling, or discharge from the puncture site.

What are the risks?

Blood: During a blood draw, a hematoma (blood-filled bump under the skin) or slight bleeding from the puncture site may occur. After a blood draw, a bruise or infection may occur at the puncture site. The person doing this test may need to perform it more than once. Talk to your healthcare worker if you have any concerns about the risks of this test.

What are normal results for this test?

Laboratory test results may vary depending on your age, gender, health history, the method used for the test, and many other factors. If your results are different from the results suggested below, this may not mean that you have a disease. Contact your healthcare worker if you have any questions. The following are considered to be normal results for this test:

  • Adults: <15 ng/mL (<15 mcg/L) [10]
  • Black adults: 10% to 15% higher than Caucasian [2]

What follow up should I do after this test?

Ask your healthcare worker how you will be informed of the test results. You may be asked to call for results, schedule an appointment to discuss results, or notified of results by mail. Follow up care varies depending on many factors related to your test. Sometimes there is no follow up after you have been notified of test results. At other times follow up may be suggested or necessary. Some examples of follow up care include changes to medication or treatment plans, referral to a specialist, more or less frequent monitoring, and additional tests or procedures. Talk with your healthcare worker about any concerns or questions you have regarding follow up care or instructions.

Where can I get more information?

Related Companies

  • National Center on Birth Defects and Developmental Disabilities, CDC -
  • National Institute of Child Health and Human Development -
  • March of Dimes Birth Defects Foundation -


[1] Canick JA, Kellner LH, & Bombard AT: Prenatal screening for open neural tube defects. Clin Lab Med 2003; 23:385-394.

[2] Benn PA, Clive JM, & Collins R: Medians for second-trimester maternal serum alpha-fetoprotein, human chorionic gonadotropin, and unconjugated estriol; differences between races or ethnic groups. Clin Chem 1997; 43(2):333-7.

[3] Chan A, Robertson EF, Haan EA, et al: The sensitivity of ultrasound and serum alpha-fetoprotein in population-based antenatal screening for neural tube defects. South Australia 1986-1991. Br J Obstet Gynaecol 1995; 102(5):370-6.

[4] Rose NC & Mennuti MT: Maternal serum screening for neural tube defects and fetal chromosome abnormalities. West J Med 1993; 159(3):312-317.

[5] Bock JL: Current issues in maternal serum alpha-fetoprotein screening. Am J Clin Pathol 1992; 97(4):541-554.

[6] Killam WP, Miller RC, & Seeds JW: Extremely high maternal serum alpha-fetoprotein levels at second-trimester screening. Obstet Gynecol 1991; 78(2):257-61.

[7] Waller DK, Lustig LS, Cunningham GC, et al: Second-trimester maternal serum alpha-fetoprotein levels and the risk of subsequent fetal death. N Engl J Med 1991; 325(1):6-10.

[8] Johnson AM, Palomaki GE, & Haddow JE: Maternal serum alpha-fetoprotein levels in pregnancies among black and white women with fetal open spina bifida: a United States collaborative study. Am J Obstet Gynecol 1990; 162(2):328-31.

[9] Wald NJ, Cuckle H, Brock JH, et al: Maternal serum-alpha-fetoprotein measurement in antenatal screening for anencephaly and spina bifida in early pregnancy. Report of U.K. collaborative study on alpha-fetoprotein in relation to neural-tube defects. Lancet 1977; 1(8026):1323-32.

[10] Kratz A, Ferraro M, Sluss PM, et al: Case records of the Massachusetts General Hospital: laboratory values. N Engl J Med 2004; 351(15):1549-1563.

Last Updated: 7/4/2018
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites.

All rights reserved