Alpha-fetoprotein in norm and in pathology

Alpha-fetoprotein is a substance of protein origin, which is produced in the yolk sac of the embryo, after birth - in the digestive tract, as well as in liver cells. Normally, the body contains up to 15 ng / ml.

Alpha-fetoprotein is determined during pregnancy to diagnose malformations of the fetus. The definition of this indicator is also applied in oncology. Alpha-fetoprotein is a cancer marker for testicular and liver cancer. In about 70% of men with a testicular tumor, its level rises, especially when metastasizing the process.

Initially, this protein substance is synthesized in the ovaries with a yellow body. In the fifth week the fetus begins to produce it. Alpha-fetoprotein protects the fetus from the mother's immune system, for which it is a foreign agent.

Its concentration increases proportionally both in the blood of the embryo, and in the blood of the mother. The optimal value of this indicator for diagnosis is 12-16 weeks. At 32-34 week of pregnancy reaches the maximum level of alpha-fetoprotein. The norm of a healthy person is reached already in the first year of a child's life.

The methods of research significantly influence the definition of this indicator. The standard deviation from the norm of the content of alpha-fetoprotein was the multiplicity of the median (MoM). The median is the average in an ordered series of values of protein concentration in the norm during pregnancy at a given time. Thus, it is possible to compare alpha-fetoprotein during pregnancy at different times, as well as analyzes done in different laboratories. The levels of this indicator from 0.5 to 2.5 MoM are normal.

An increase in alpha-fetoprotein may be a sign:

• Tumors of the bronchi.
• Metastases in the liver.
• Cancer of the stomach, pancreas, lungs, liver, colon, breast.
• Germinal tumors of testicles and ovaries.

Temporarily and slightly alpha-fetoprotein increases with the following pathologies:

• Cirrhosis of the liver,
• Chronic liver failure,
• Chronic alcoholism with the presence of liver damage,
• Chronic or acute viral hepatitis.

Increased this indicator for pregnancy is in the following cases:

• Multiple pregnancy.
• Renal pathology in the fetus.
• Umbilical hernia in fetus.
• Necrosis of the liver in the fetus.
• The developmental defects of the neural tube (rahishisis, anencephaly).
• Non-growth of the anterior abdominal wall of the fetus.
• Other malformations.

However, a reduced alpha-fetoprotein during pregnancy can be indicative of the following:

• False pregnancy.
• Delayed development.
• Fetal death.
• Bubble skidding.
• Spontaneous miscarriage.
• Trisomy on 18 or 21 chromosomes.

A decreased concentration of alpha-fetoprotein may indicate an incorrect determination of the gestation period, that is, conception occurred later.

In gynecology at the present stage, this indicator is the main marker of fetal pathology and chromosomal abnormalities in pregnancy. Deviations from normal fetal development change the normal concentration of this protein substance in the mother's blood. Of course, it is necessary to carry out not only the definition of this indicator, since it is of little informative. It is necessary to conduct an ultrasound study, so you can exclude the wrong definition of the term, multiple pregnancies and so on. It is also necessary to determine and placental hormones (chorionic gonadotropin and free estriol), allowing to give an accurate assessment of the fetoplacental system. Their combination with alpha-fetoprotein is determined in a triple test, which allows you to determine the risk of various developmental malformations in the fetus.