Maternal Serum Alpha-Fetoprotein (AFP) with Additional Obstetric/Neonatal Screening Markers
This test measures key proteins and substances in your blood to help assess fetal development and screen for potential birth defects or health conditions during pregnancy.
["Early detection of genetic risks and fetal development monitoring through blood markers."]
Key facts at a glance
- LOINC
- 82356-7
- Short code
- OB Midwife Consult note
- Synonyms
- OB Midwife Consult note
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- obstetrics-midwife
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What This Test Measures
Your blood sample includes measurements for Alpha-Fetoprotein (AFP), which is a protein produced primarily by the fetal liver and yolk sac. Additional markers may include other substances like human chorionic gonadotropin (hCG) or inhibin A, depending on the specific panel ordered. These tests are often part of a prenatal screening to identify risks for conditions such as neural tube defects or chromosomal abnormalities.
Why It’s Done During Pregnancy
This test is typically performed between 15 and 22 weeks of pregnancy as part of a first-trimester or second-trimester screening. It helps healthcare providers assess the risk of certain birth defects and chromosomal conditions, allowing for early planning of further diagnostic tests if needed.
How the Test Works
Blood is drawn from a vein in your arm, and the sample is analyzed using sensitive laboratory techniques, such as immunoassays or other specialized methods, to measure the levels of these proteins and substances. The results are compared to established reference ranges to determine the risk level.
Preparation for the Test
No special preparation is needed, but you may be asked to fast for a few hours before the test if instructed by your healthcare provider. Wear comfortable clothing and bring any necessary identification.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated or low levels of AFP and other markers can indicate an increased risk for conditions like spina bifida, Down syndrome, or other chromosomal abnormalities. While not a diagnostic test, these results guide further evaluation, such as amniocentesis or ultrasound studies, to provide more detailed information about your pregnancy.
Frequently asked questions
When might I get this test?
What do my results mean?
Can I influence the results?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy