AFP Notes and MCQ (past questions)
Increase in Alpha-fetoprotein (AFP) is seen in:
a. Hepatoblastoma ✅ (Correct Answer)
b. Neuroblastoma
c. Thymoma
d. Angiosarcoma
Answer: a. Hepatoblastoma
Solution:
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Alpha-fetoprotein (AFP) is a glycoprotein synthesized by the fetal yolk sac, fetal gastrointestinal tract, and fetal liver.
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AFP concentration increases steadily until about 13 weeks of gestation (peak concentration in fetal plasma) and then gradually declines.
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Peak maternal serum AFP occurs at 30–32 weeks of pregnancy.
Causes of Increased AFP:
1. Liver tumors:
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Hepatoblastoma
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Hepatocellular carcinoma
2. Germ cell tumors:
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Yolk sac tumor (also known as Endodermal sinus tumor)
3. Others:
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Neuroblastoma (Note: Can be associated but less specific compared to hepatoblastoma)
Causes of Increased Maternal Serum AFP (MSAFP):
Mnemonic: TAF-AFP
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T: Thin pregnancy
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A: Anencephaly
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F: Fetal anomalies (e.g., open neural tube defects, abdominal wall defects)
Detailed list:
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Miscalculation of gestational age (most common cause)
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Open Neural Tube Defects (NTDs):
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Anencephaly
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Encephalocele
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Spina bifida
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Abdominal wall defects:
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Gastroschisis
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Omphalocele
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Upper GI obstructions
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Renal anomalies
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Cystic hygroma
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Pilonidal sinus
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Ectodermal dysplasia
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Aplasia cutis
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Cystic adenomatoid malformation of the lungs
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Multiple gestations
Causes of Decreased Amniotic Fluid AFP (AF-AFP):
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Hydatidiform mole
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Trisomy 21 (Down syndrome)
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Trisomy 18 (Edwards syndrome)
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Trisomy 13 (Patau syndrome)
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Thin pregnancy
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Misdated pregnancy
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Missed abortion
