AFP in amniotic fluid is tested by which method?

AFP in amniotic fluid is tested by which method?

• A. Amniocentesis or maternal blood test
• B. Urine test for AFP
• C. Cord blood sampling
• D. Placental biopsy

Answer: (A)

Measuring AFP in the amniotic fluid requires obtaining the fluid directly from the amniotic cavity, which is done by amniocentesis. After collecting the sample, an AFP immunoassay is performed to determine the concentration of alpha-fetoprotein in that fluid. Maternal blood testing for AFP (screening of the mother's serum) is a different test that assesses AFP levels in the mother, not in the amniotic fluid, so it’s a separate approach from evaluating amniotic fluid AFP. Urine testing cannot reflect fetal AFP in the amniotic cavity, cord blood sampling would measure AFP in fetal blood rather than amniotic fluid, and placental biopsy is not used to measure AFP. Therefore, obtaining amniotic fluid via amniocentesis (with subsequent AFP assay) is the method specifically used to test AFP in amniotic fluid.