The Alpha-Fetoprotein (AFP) is a critical screening test that examines the amount of alpha-fetoprotein in the pregnant woman’s blood. It is a part of what’s known as the Triple Test, which uses a blood test to examine the mother’s blood for AFP, human chorionic gonadotropin (Hcg), and estriol (a type of estrogen).
This is not a diagnostic test. Instead, the levels of alpha-fetoprotein found in the pregnant person’s blood indicate potential problems. AFP levels alert the high-risk pregnancy specialist to further explore the risk of a birth defect or genetic condition.
It takes a high-risk pregnancy specialist to understand the intricacies of this test. Patients in the Los Angeles area seek the expert counsel of Dr. Steve Rad, a double-board certified Obstetrician-Gynecologist with sub-specialty training in Maternal-Fetal Medicine (MFM).
Dr. Rad, a high-risk OB/GYN, advises expectant mothers to remain constantly vigilant about their conditions. Low-risk pregnancies can quickly escalate to high risk.
Dr. Rad and his team at the Los Angeles Fetal and Maternal Care Center have decades of perinatology experience. They are among the very best high-risk pregnancy specialists in Los Angeles. The team is also available to provide expert second opinions.
What is the alpha-fetoprotein test?
AFP is a protein found in the liver of the developing fetus. Some of this protein moves from the placenta to the mother’s bloodstream during development. The AFP test (also called Maternal serum alpha-fetoprotein) studies the serum AFP level during the second trimester of pregnancy.
Too much or too little alpha-fetoprotein can signal problems with the fetus. AFP levels can signal the following conditions:
- Abnormal development of the baby’s spine or brain (neural tube defect)*
- Chromosomal abnormalities (Down syndrome)
- Multiple pregnancy (twins, triplets)
- Miscalculated due date (AFP levels fluctuate during pregnancy)
*75% to 90% of babies with neural defects are found during AFP screening.
When is the AFP test done?
The AFP test is most accurate during weeks 16 to 18 of pregnancy. It is important to have precise pregnancy dating because AFP levels fluctuate.
Every pregnant patient should be offered an AFP test, but it is especially advised for:
What does AFP test for?
Alpha-fetoprotein levels measure the volume of AFP. The high-risk OB then merges the results with the mother’s age and ethnic background to measure the possibility of a genetic disorder.
High levels of AFP could indicate spina bifida or anencephaly. High levels can also hint at defects with the esophagus or failure of the abdomen to close. Most of the time, high levels of AFP point to the wrong dating of pregnancy.
Low levels of AFP point to potential chromosomal conditions such as Edwards Syndrome.
This test is also used in other areas of medicine to diagnose liver diseases like hepatitis C or to look for tumor markers for things like liver cancer and lymphoma and for differentiating malignant from benign tumors.
AFP test results
Once again, the AFP only tells doctors that you are at risk for a disorder. It does not make a definitive diagnosis. Abnormal test results indicate the need for additional testing during a follow-up visit.
Statistics indicate that there are between 25 and 50 abnormal AFP test results for every thousand pregnancies. However, of these abnormal results, only 3 – 6% will have a baby with a birth defect.
Many times, after an abnormal reading, the doctor will take another blood sample or take a high-definition ultrasound.
If the patient has a family history of birth defects or other risk factors, the doctor may recommend an amniocentesis during the second trimester. During this procedure, the doctor withdraws a sample of the amniotic fluid that surrounds the baby. This liquid contains fetal cells and various proteins that can be studied.
Your healthcare provider will discuss potential risks with you before the test. At that time the parents can weigh the pros and cons of the procedure.
What about further testing?
The idea of pursuing further testing is a personal choice and may vary from person to person.
Additional testing not only confirms a diagnosis but gives the prospective parents opportunities such as:
Other parents may decide not to pursue further testing for personal reasons:
- They want to give birth no matter the results
- Not carrying the child to term is not an option
- Fear of harming the baby during testing
More about Dr. Rad
Perinatologist Dr. Rad and his world-class Maternal-Fetal Medicine (MFM) obstetrics and gynecology team at Los Angeles Fetal and Maternal Care understand your High-Risk OB and infertility needs before, during, and after birth. We provide compassionate care and help you understand your pregnancy, answer questions, and provide emotional support to safely navigate your pregnancy.
Dr. Rad has undergone rigorous training with high honors at renowned institutions including the Department of Obstetrics and Gynecology at David Geffen School of Medicine at UCLA, USC, Cedars-Sinai Medical Center, and UCSF Medical Center, as well as centers internationally in London, Austria, Israel, and Africa.
Call us at (844) 473-6100 or schedule your consultation online. We are currently accepting new patients.
We are conveniently located for patients throughout Southern California and the Los Angeles area at locations in or near Beverly Hills, Santa Monica, West Los Angeles, West Hollywood, Culver City, Hollywood, Venice, Marina del Rey, Malibu, Manhattan Beach, Newport Beach, Irvine, and Downtown Los Angeles. We also offer in-home prenatal care and a fly-in program for out-of-town and international patients. Dr. Rad even travels to patients who need him throughout the U.S. and around the world.
If you can’t make it to Dr. Rad, he also offers virtual consultations worldwide.