AFP analysis: norm, decoding

Many parents are looking forward to the birth of the planned baby. At the same time, being in position, the expectant mother is forced to take a considerable number of various tests. Among them is the analysis of AFP. And if almost everyone knows the progesterone test, then few people are familiar with alpha-fetoprotein, or AFP.

Recently, an increasing number of people turn to laboratories for research on tumor markers. These substances have a different nature: it can be proteins or their derivatives, special enzymes, hormones. They are vital products of any tumor or are produced by our body in response to an attack by cancer cells. AFP is also a tumor marker, and will be discussed in this article. In total, experts identified 20 of their species.

What is AFP?

As already mentioned above, AFP analysis belongs to the category of studies on tumor markers, which signal how the pregnancy proceeds. The specified antigen is normally produced directly by the embryo in the body of a pregnant woman. But after the birth of a child, its production occurs in the liver.

Usually, any body, including the unborn child, in the body perceives the immunity as foreign. And since the embryo is in no way such a body, a certain amount of alpha-fetoprotein protects the fetus from rejection by the body. Initially, antigen synthesis occurs in the corpus luteum of the ovaries. With the onset of the fifth week of pregnancy, the fetus already assumes the obligation to produce AFP.

At the same time, its concentration increases both in the mother’s blood and in the baby’s blood. The highest content of this protein, as shown by AFP analysis, is observed at the 32-34th week. After the birth of the child and during the first year of his life, the content of AFP returns to normal.

The important role of AFP during pregnancy

The role of the protein can hardly be overestimated, since it is the guarantor of preservation of the fetus and prevents attempts to spontaneous miscarriage. But sometimes it is produced in too large or insufficient quantities. This circumstance should alert any professional gynecologist. In such cases, this may indicate that the fetal bladder does not develop correctly. Sometimes this is a signal that there are some problems that relate to the development of the child at the genome level.

The level of AFP can be shown by AFP analysis, which is carried out after 12 weeks of pregnancy. At this time, the level of alpha-fetoprotein will reach a significant limit. If during the correct decryption other figures are present, then, probably, there are any deviations.

However, an accurate diagnosis based on an alpha-fetoprotein analysis alone is not possible, as errors occur. Its increased level may indicate different things:

• multiple pregnancy;
• embryo liver necrosis ;
• anencephaly;
• umbilical hernia;
• pathology of the kidneys.

The development of internal organs with an anomaly also leads to an increase in the level of AFP.

A reduced concentration of alpha-fetoprotein may be a sign that:

• there is a Down pathology;
• there is a delay in the development of the embryo;
• fetal death occurred.

In some cases, with a low AFP level, there is a risk of miscarriage. And sometimes its content is so low that, based on what the AFP analysis shows (normal for women or not), doctors conclude that the pregnancy is false.

Abnormality during pregnancy

Any deviations in protein content from normal values ​​are an important criterion for observing the course of pregnancy. In this case, it becomes possible for the attending physician to prescribe additional studies during which this or that diagnosis will be confirmed or refuted.

It is only worth noting that pregnancy can be terminated no later than the 20th week. Shortly before this period, an ultrasound scan is performed as a control measure. In addition, it is important to check the level of hCG ( human chorionic gonadotropin ). If all the studies carried out confirm the fact that a child is likely to be born with a pathology, the burden of making a responsible decision lies with the woman herself.

What else does AFP indicate

An AFP analysis during pregnancy is not always, decryption is necessary only for expectant mothers. In some cases, this tumor marker is an important study in the diagnosis of any serious illness in adult patients. Normally, the indicator is not more than 10 PIECES / ml. An increase in this level suggests that a malignant tumor began to develop in the human body, often with metastases. For more information on the AFP norm, see the special section below.

If the AFP content is below normal, then this is a sign of abnormal processes in the development of the liver:

• cirrhosis;
• chronic liver failure;
• Hepatitis B.

In addition, based on the state of the liver, it can be concluded that the presence or absence of chronic alcoholism.

Analysis preparation

If the doctor has prescribed a study such as the analysis of AFP and hCG during pregnancy, preparation is practically not required. Usually, everything goes as with a normal blood sampling from a vein. This means that in the next 5-8 hours you can not eat. In pregnant women, the period should be no less than 14 weeks. However, the interval between the 16th and 18th weeks is considered the most suitable for blood sampling. The procedure itself is carried out in the morning, during it 10 ml of biomaterial is taken.

And since the procedure is performed on an empty stomach and is complicated, the patient after it needs to sit quietly, relaxing, for 15 minutes. This is especially true for expectant mothers. During this short period, strength will be restored, weakness will go away, and the risk of losing consciousness will decrease.

What may affect the analysis

In addition to proper preparation, it is important to consider that some factors can distort the analysis of AFP during pregnancy. The norm in this case is achieved if simple rules are observed. At dinner, it is best to refrain from eating foods with different spices, as well as fatty, smoked and fried foods.

Physiotherapeutic procedures such as ultrasound and massage, as well as instrumental methods like radiography, MRI, and computed tomography, can also affect the analysis. Therefore, they are not recommended to be done on the same day as the AFP study. As for alcoholic beverages, their consumption should also be delayed. At least until the end of the analysis.

It is also noted that the representatives of the Negroid race have a higher concentration of AFP, while the Mongoloid nation has a much lower concentration. The presence of an endocrine disease like diabetes mellitus or viral diseases in the past should also be taken into account.

Where can I get an analysis?

Currently, in any public or private laboratory, you can pass an analysis of AFP and hCG during pregnancy. The norm will be known more accurately if experienced professionals who have research methods and the necessary equipment are involved in such institutions. The cost of such an analysis ranges from 300 to 600 rubles.

If you need to undergo such a study, you should not try to independently understand the result, only a specialist should deal with decryption. And only an integrated approach will provide an accurate answer. That is, the most informative result will be obtained if laboratory studies are combined with instrumental ones. Moreover, data monitoring should be carried out in the same laboratory using one reagent.

Decoding analysis and AFP norm

After passing the analysis, the result will be ready in two days, but if necessary in emergency cases it can be obtained after two hours. Often, in order to have reliable data, in the second trimester of pregnancy, the analysis should be carried out in combination with ultrasound, research on placental hormones and other diagnostic methods.

Each laboratory, when analyzing the level of AFP content, uses its own methodology and reagents. But at the same time, the units of measurement are indicated in all cases the same way: IU / ml or MoM . For example, if an AFP and hCG analysis is performed during pregnancy, the norm (MoM) is 0.5-2. However, if the laboratory uses other measures (IU / ml), then the protein level, depending on the gestational age, will change as follows (see table below).

As mentioned above, in men the norm is not more than 10 IU / ml. The same goes for non-pregnant women.

Indications for

It is recommended that all pregnant women take an AFP test no later than the 12th week of pregnancy. This is necessary to detect the presence or absence of deviations. And if they are absent, then the process proceeds in normal mode. But if available, the attending physician prescribes a re-analysis or additional studies.

Sometimes donating blood for the analysis of AFP and hCG is simply necessary without objection. This applies to those cases when the child is conceived by blood relatives, the baby was born with a malformation or pathology inherited. This is especially critical if a woman first becomes pregnant at the age of over 35.

Still need to take into account the following situations:

• If during attempts to get pregnant a woman has a spontaneous miscarriage.
• Mother taking before pregnancy or at the initial stage of toxic medications that affect the embryo.
• The presence of any hereditary pathology or mutation at the genetic level in future parents.

In addition, it is simply necessary to undergo a study if a woman underwent an X-ray examination at an early stage of bearing a child.