Serum alpha—fetoprotein level

Introduction

Alpha-fetoprotein (AFP) is a plasma protein produced by the embryonic yolk sac and the fetal liver. AFP levels in serum, amniotic fluid, and urine functions as a screening test for congenital disabilities, chromosomal abnormalities, as well as some other adult occurring tumors and pathologies. This tumor marker is a glycoprotein encoded by the AFP gene on chromosome 4q25. Prenatal levels in developing human embryo rise from the end of the first trimester and begin to fall after 32 weeks of gestation. Maternal serum AFP forms part of the triple or quadruple screening tests for fetal anomaly.[1][2][3]

Potential Diagnosis

 Pregnant maternal serum AFP levels elevated:

• Neural tube defects (e.g., spina bifida, anencephaly)
• Omphalocele
• Gastroschisis

Pregnant maternal serum AFP low levels:

• Down syndrome

Non-pregnant female or male adult AFP elevated:

• Hepatocellular cancer
• Metastatic liver cancer
• Liver cirrhosis
• Hepatitis
• Germ cell tumors
• Yolk sac tumor
• Ataxia telangiectasia



References

1.

Sharony R, Dayan D, Kidron D, Manor M, Berkovitz A, Biron-Shental T, Maymon R. Is the ratio of maternal serum to amniotic fluid AFP superior to serum levels as a predictor of pregnancy complications? Arch Gynecol Obstet. 2016 Apr;293(4):767-70. [PubMed]

2.

Öztürk H, Erkaya S, Altınbaş S, Karadağ B, Vanlı Tonyalı N, Özkan D. The role of unexplained high serum alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG) levels in the second trimester to determine poor obstetric outcomes. Turk J Obstet Gynecol. 2014 Sep;11(3):142-147. [PMC free article] [PubMed]

3.

Rood K, Stiller R. Hereditary persistence of alpha-fetoprotein: a rare cause for unexplained alpha-fetoprotein elevations in pregnancy. Conn Med. 2013 Jan;77(1):43-5. [PubMed]

4.

Gkogkos P, Androutsopoulos G, Vassilakos P, Panayiotakis G, Kourounis G, Decavalas G. Mid-trimester maternal serum AFP levels in predicting adverse pregnancy outcome. Clin Exp Obstet Gynecol. 2008;35(3):208-10. [PubMed]

5.

Chen CP, Chern SR, Cheng SJ, Chang TY, Yeh LF, Lee CC, Pan CW, Wang W, Tzen CY. Second-trimester diagnosis of complete trisomy 9 associated with abnormal maternal serum screen results, open sacral spina bifida and congenital diaphragmatic hernia, and review of the literature. Prenat Diagn. 2004 Jun;24(6):455-62. [PubMed]

6.

Shipp TD, Wilkins-Haug L. The association of early-onset fetal growth restriction, elevated maternal serum alpha-fetoprotein, and the development of severe pre-eclampsia. Prenat Diagn. 1997 Apr;17(4):305-9. [PubMed]

7.

Benn PA, Horne D, Briganti S, Rodis JF, Clive JM. Elevated second-trimester maternal serum hCG alone or in combination with elevated alpha-fetoprotein. Obstet Gynecol. 1996 Feb;87(2):217-22. [PubMed]

8.

Wenstrom KD, Owen J, Davis RO, Brumfield CG. Prognostic significance of unexplained elevated amniotic fluid alpha-fetoprotein. Obstet Gynecol. 1996 Feb;87(2):213-6. [PubMed]