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Alpha-Fetoprotein (AFP) Test

Test Overview

An alpha-fetoprotein (AFP) blood test checks the level of AFP in a pregnant woman's blood. AFP is a substance made in the liver of an unborn baby (fetus). The amount of AFP in the blood of a pregnant woman can help see whether the baby may have such problems as spina bifida and anencephaly. An AFP test can also be done as part of a screening test to find other chromosomal problems, such as Down syndrome (trisomy 21) or Edwards syndrome (trisomy 18). An AFP test can help find an omphalocele, a congenital problem in which some of the baby's intestines stick out through the belly wall.

Normally, low levels of AFP can be found in the blood of a pregnant woman. No AFP (or only a very low level) is generally found in the blood of healthy men or healthy, nonpregnant women.

The level of AFP in the blood is used in a serum quadruple screening test. This test is often done between 15 and 22 weeks. It checks the levels of four substances in a pregnant woman's blood. They are the hormone inhibin A, alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and a type of estrogen (unconjugated estriol, or uE3). The levels of these substances—along with a woman's age and other factors—help the doctor estimate the chance that the baby may have certain problems or birth defects.

Screening tests are used to see what the chance is that your baby has a certain birth defect. If a screening test is positive, it means that your baby is more likely to have that birth defect and your doctor may give you the option to have a diagnostic test to make sure.

Men, nonpregnant women, and children

In men, nonpregnant women, and children, AFP in the blood can mean that certain types of cancer—especially cancer of the testicles, ovaries, stomach, pancreas, or liver—are present. High levels of AFP may also be found in Hodgkin disease, lymphoma, brain tumors, and renal cell cancer.

Why It Is Done

The AFP test is done to:

  • Check the developing baby (fetus) of a pregnant woman for brain or spinal problems (called neural tube defects).
  • Check the developing baby (fetus) of a pregnant woman for Down syndrome.
  • Find certain cancers, especially cancer of the testicles, ovaries, or liver.
  • Check how well treatment for cancer is working.

How To Prepare

You do not need to do anything before you have this test.

If you are pregnant, you will be weighed before the blood test, because the test results will be based on your weight. The test results are also based on race, age, and how many weeks you are in your pregnancy.

How It Is Done

A health professional uses a needle to take a blood sample, usually from the arm.

How It Feels

When a blood sample is taken, you may feel nothing at all from the needle. Or you might feel a quick sting or pinch.

Risks

There is very little chance of having a problem from this test. When a blood sample is taken, a small bruise may form at the site.

Results

Normal

Each lab has a different range for what's normal. Your lab report should show the range that your lab uses for each test. The normal range is just a guide. Your doctor will also look at your results based on your age, health, and other factors. A value that isn't in the normal range may still be normal for you.

In pregnant women, the amount of AFP gradually rises starting in the 14th week of pregnancy. It continues to rise until a month or two before the woman gives birth, and then it slowly decreases. Values are generally slightly higher for black women than they are for white women. Values are slightly lower for Asian women than they are for white women. An accurate estimate of the age of the baby is needed to understand the AFP value correctly.

The normal range of AFP values is adjusted for each woman's age, weight, and race; whether she has diabetes that needs injections of insulin; and the age of her baby (gestational age). If the age of the baby is changed after an ultrasound, the AFP must then be adjusted as well. Each woman and her doctor need to look at the range of AFP values that is normal for her when she has an AFP test.

A normal AFP result does not guarantee a normal pregnancy or healthy baby.

High values

  • In a pregnant woman, high alpha-fetoprotein values can mean:
    • The age (gestational age) of the baby is wrong.
    • The woman is pregnant with more than one baby, such as twins or triplets.
    • The baby has a neural tube defect.
    • The baby's intestines or other abdominal organs are outside the body (called an abdominal wall defect or omphalocele). Surgery after birth will be needed to correct the problem.
    • The baby is not alive.
  • In a nonpregnant adult, high alpha-fetoprotein values can mean:

Low values

In a pregnant woman, a low level of alpha-fetoprotein can mean:

  • The age (gestational age) of the baby is wrong.
  • The baby may have Down syndrome.

In a nonpregnant adult, alpha-fetoprotein is not normally present.

AFP test results can be abnormal, even when nothing is wrong with the baby.

Credits

Current as of: April 30, 2024

Author: Ignite Healthwise, LLC Staff
Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

Current as of: April 30, 2024

Author: Ignite Healthwise, LLC Staff

Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

Dear patient

I am excited to announce that I will be relocating my practice to Houston Methodist DeBakey Cardiology Associates. Starting November 4, 2024, my new address will be:

Houston Methodist DeBakey Cardiology Associates
6550 Fannin St.
Smith Tower, Suite 1901
Houston, TX 77030

Please note that my phone number and fax number will also change to the following:
24-Hour Telephone: 713-441-1100
Fax: 713-790-2643
Clinical Support Telephone (M-F, 8-5): 713-441-3515

I am excited about caring for you in my new office and hope you will make the transition with me. I will also continue to refill your medications as I have in the past. To assist, please provide your pharmacy with my new contact information.

Please consider checking your prescription refills to verify that you have enough medication on hand to last you until your next visit. Please note that your medical records will remain at my former office until you authorize their transfer. If you choose for me to continue providing your medical care, please complete and sign the enclosed “Authorization for Release of Medical Records” form and fax it to 713-790-2643. Once we receive your authorization, we will be happy to process the request for you.

Thank you for entrusting me with your medical care. My new team and I are dedicated to making this transition as seamless as possible. For help scheduling an appointment and transitioning your care, please call my new office number above.

I look forward to continuing your care at my new location.

Sincerely,
Gopi A. Shah, MD

Dear patient

Dr. Albert Raizner, Dr. Michael Raizner, and Dr. Mohamed El-Beheary are excited to announce that our practice, Houston Cardiovascular Associates, will merge with Houston Cardiovascular Associates on November 1, 2024.

Our new offices are similarly located in Houston, near the Texas Medical Center and in Sugar Land. Our in-hospital care will continue at Houston Methodist Hospital in the Texas Medical Center and Houston Methodist Sugar Land Hospital. Importantly, our new offices expand our services with state-of-the-art equipment and amenities. Our core values will always be, as they began over 40 years ago when Dr. Albert Raizner founded HCA:

Integrity – Compassion – Accountability

Our new address and contact information are:

Your medical records are confidential and remain available at our new locations. We consider it a privilege to serve as your cardiologists and look forward to your continuing with us. However, should you desire to transfer to another physician, you may request a copy of your records by contacting us at our new addresses and phone numbers listed above.

We thank you for your trust and loyalty. As always, we will continue to be here to take care of you. Please do not hesitate to contact us if you have any questions or concerns.

Sincerely,

Dr. Albert Raizner,
Dr. Michael Raizner,
Dr. Mohamed El-Beheary