AFP analysis: norm, decoding
The birth of the planned baby is eagerly awaited by many parents. At the same time, being in the position, the future mother is forced to hand over a considerable number of various analyzes. Among them there is also an analysis of AFP.And if the study on progesterone is almost universally known, then alpha-fetoprotein, or AFP, is not well known to anyone.
Recently, more and more people are turning to laboratories for research on oncomarkers. These substances have different nature: they can be proteins or their derivatives, special enzymes, hormones. They are the products of the life of a tumor or are produced by our body in response to an attack of cancer cells. AFP is also an oncomarker, and it will be described in this article. In total, specialists installed 20 of them.
What is AFP?
As mentioned above, AFP analysis belongs to the category of research on oncomarkers, which signal how the pregnancy proceeds. This antigen is normally produced directly by the embryo in the body of the pregnant woman. But after the birth of a child, its production takes place in the liver.
Usually any body, including a future child, in the body perceives immunity as an alien. And since the embryo is not such a body, a certain amount of alpha-fetoprotein protects the fetus from rejection by the body. Initially, the synthesis of the antigen occurs in the yellow body of the ovaries. With the onset of the fifth week of pregnancy, the obligation to produce AFP takes on itself a fetus.
In this case, its concentration increases in the blood of the mother, and in the blood of the baby. The highest content of this protein, as shown by AFP analysis, is observed at 32-34-th week. After the birth of the child and during the first year of his life, the content of AFP comes back to normal.
Important role of AFP during pregnancy
The role of protein is difficult to overestimate, as it is the guarantor of fetal preservation and prevents attempts of spontaneous miscarriage. But sometimes it is produced in too much or too little. This circumstance should alert any professional gynecologist. In such cases, this may indicate that the fetal bladder is developing incorrectly. Sometimes this is a signal that there are some problems that concern the development of the child at the genome level.
The level of AFP can show an AFP analysis that is performed after 12 weeks of pregnancy. At this time, the level of alpha-fetoprotein will reach a significant limit. If other digits are present during the correct interpretation, then probably there are any deviations.
However, accurate diagnosis based on an analysis of alpha-fetoprotein alone is not possible, since errors occur. Its elevated level may indicate a different:
- multiple pregnancy;
- necrosis of the embryo liver;
- anencephaly;
- umbilical hernia;
- kidney pathology.
The development of internal organs with anomaly also leads to an increase in the level of AFP.
A reduced concentration of alpha-fetoprotein may be a sign that:
- has Down's pathology;
- there is a delay in the development of the embryo;
- the fetus died.
In some cases, with a low level of AFP, there is a risk of miscarriage. And sometimes its content is so low that on the basis of what AFP analysis shows( the norm in women or not), doctors come to the conclusion that pregnancy is false.
Abnormality in pregnancy
Any variation in protein content from normal indices is an important criterion for monitoring the course of pregnancy. In this case, it becomes possible for the attending physician to prescribe additional studies in the course of which a particular diagnosis will be confirmed or refuted.
One should only note that the pregnancy can be interrupted not later than the 20th week. Shortly before this period, ultrasound is used as a control measure. In addition, it is important to check the level of hCG( human chorionic gonadotropin ).If all the studies conducted confirm the fact that a child with high probability can be born with a pathology, the burden of making a responsible decision lies with the woman herself.
What does the AFP content of
Not always an analysis of AFP in pregnancy, decoding is necessary only for future mothers. In a number of cases, this oncomarker is an important study in diagnosing a serious illness in adult patients. Normally the indicator is no more than 10 U / ml. An increase in this level suggests that a malignant tumor has developed in the human body, often with metastases. For more details on the AFP norm, see the special section below.
If the AFP content is lower than normal, this is a sign of abnormal processes in liver development:
- cirrhosis;
- chronic hepatic insufficiency;
- hepatitis B.
In addition, based on liver status, it can be concluded about the presence or absence of chronic alcoholism.
Preparation for analysis of
If the doctor has appointed such a study, as an analysis of AFP and hCG in pregnancy, preparation is almost not required. Usually everything goes like with the usual blood sampling from the vein. And this means that in the next 5-8 hours you can not eat. In pregnant women, the term should be no less than 14 weeks. However, the interval between the 16th and 18th weeks is considered the most suitable for blood collection. The procedure itself is carried out in the morning, during which 10 ml of biomaterial is taken.
And since the procedure is performed on an empty stomach and is difficult, the patient after it needs to sit quietly, relaxed, for 15 minutes. In particular, this applies to expectant mothers. In this small period, the forces will recover, weakness will go away, and the risk of losing consciousness will decrease.
What can affect the analysis of
In addition to proper preparation, it is important to consider that some factors may distort the AFP analysis during pregnancy. The norm is achieved if you follow simple rules. For dinner, it is best to refrain from eating food with various spices, as well as fatty, smoked and fried foods.
Such physiotherapy procedures as ultrasound and massage, as well as instrumental methods such as radiography, MRI, computed tomography, can also affect the analysis. Therefore, they are not recommended to be done on the same day as AFP.As for alcoholic beverages, their use 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 for the Mongoloid nation it is much lower. Another thing to consider is the presence of an endocrine disease like diabetes or viral diseases in the past.
Where can I take an analysis?
At present, in any public or private laboratory, it is possible to take AFP and hCG analysis in pregnancy. The norm will be known more accurately if in such institutions experienced specialists who own the research technique and the necessary equipment will be involved. The cost of such an analysis is in the range of 300 to 600 rubles.
If necessary, to undergo such a study, you should not try to understand the result yourself, only the specialist should decipher it. And only an integrated approach will provide an accurate answer. That is, the most informative result will be obtained if laboratory research is combined with instrumental. At the same time, data monitoring should be carried out in the same laboratory using a single reagent.
Analysis of AFD and AFD
After 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 conjunction with ultrasound, a study on placental hormones and other diagnostic techniques. 
Each laboratory uses its own methodology and reagents to analyze the level of AFP content. But in this case the units of measurement are designated in all cases in the same way: ME / ml or MoM .For example, if the analysis of AFP and hCG is performed in pregnancy, the norm( MoM) is 0.5-2.However, if the laboratory uses other measures( IU / ml), the protein level, depending on the gestational age, will vary as follows( see table below).
| Week | Value, IU / mL |
| 5-11th | Less than 15 |
| 13-15th | 15-62 |
| 15-19th | 15-95 |
| 20-25-I | 28-125 |
| 25-27th | 50-140 |
| 28-31st | 68-150 |
| 32-34th | 100-251 |
As mentioned above, in men the norm is no more than 10 IU /ml. The same applies to non-pregnant women.
Indications for
It is recommended that all pregnant women be evaluated for AFP at the latest on 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 in their presence, the attending physician prescribes a second analysis or additional studies.
Occasionally donate blood for analysis AFP and hCG just need no objection. This applies to cases where a child is conceived by blood relatives, the baby was born with a developmental malformation or a pathology transmitted by inheritance. This is especially critical if a woman first becomes pregnant over the age of 35.
Still it is necessary to consider the following situations:
- If in the course of attempts to become pregnant a woman has a spontaneous miscarriage.
- Admission of the mother before pregnancy or at the initial period of toxic medications that affect the embryo.
- The presence of any hereditary pathology or mutation at a genetic level in future parents.
In addition, it is simply necessary to undergo a study if, at an early gestation period, a woman underwent X-ray examination.