Alphafetoprotein (amniotic fluid)
Test Code
AF AFP
Associations
Neural tube defect
Methodology
Chemiluminescent Immunoassay / Electrophoresis
CPT Codes
82106 - Alpha-fetoprotein, amniotic
Turnaround Time
Within 5 days
Specimen Requirements
2.5 mL amniotic fluid in a sterile container
Specimen Stability
Storage & Handling
Causes for Rejection
Exposed to extreme heat
Reference Range
By report based upon weeks of gestation
Related Content
When AFP levels are significantly elevated, reflex to Acetycholinesterase (AChE) testing to rule out a neural tube defect (NTD).
Description
Alpha-fetoprotein (AFP) is found in both fetal serum and also amniotic fluid. This protein is produced early in gestation by the fetal yolk sac and then later in the liver and gastrointestinal tract. This protein’s level increases and decreases during certain weeks of pregnancy, which is why accurate pregnancy dating is crucial.
The AFP test measures high and low levels of alpha-fetoprotein. The results are combined with the mother’s age and ethnicity to assess probabilities of potential genetic disorders. High levels of AFP may suggest the developing baby has a neural tube defect such as spina bifida or anencephaly. High levels of AFP may also suggest defects with the esophagus or a failure of the baby's abdomen to close. Low levels of AFP and abnormal levels of hCG and estriol may indicate that the developing baby has Trisomy 21 (Down syndrome), Trisomy 18 (Edwards syndrome) or another type of chromosome abnormality.
The AFP test measures high and low levels of alpha-fetoprotein. The results are combined with the mother’s age and ethnicity to assess probabilities of potential genetic disorders. High levels of AFP may suggest the developing baby has a neural tube defect such as spina bifida or anencephaly. High levels of AFP may also suggest defects with the esophagus or a failure of the baby's abdomen to close. Low levels of AFP and abnormal levels of hCG and estriol may indicate that the developing baby has Trisomy 21 (Down syndrome), Trisomy 18 (Edwards syndrome) or another type of chromosome abnormality.