The birth of a planned baby is eagerly awaited by many parents. At the same time, being in a position, the expectant mother is forced to take a considerable number of various tests. Among them is the analysis of AFP. And if the study on progesterone is known to almost everyone, then alpha-fetoprotein, or AFP, is not familiar to anyone.
Recently, more and more people are turning to laboratories for research on tumor markers. These substances are of a different nature: they can be proteins or their derivatives, special enzymes, hormones. They are the waste products of a tumor or are produced by our body in response to an attack by cancer cells. AFP is also a tumor marker, and it will be discussed in this article. In total, experts have established 20 types of them.
What is AFP?
As mentioned above, AFP analysis belongs to the category of studies on tumor markers that signal how the pregnancy is proceeding. The specified antigen is normally produced directly by the embryo in the body of a pregnant woman.women. But after the birth of a child, its production occurs in the liver.
Usually, any body, including an unborn child, is perceived by the body's 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 responsibility for the production of AFP is taken over by the fetus.
At the same time, its concentration grows both 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 the 32-34th week. After the birth of a 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 protein can hardly be overestimated, since it is the guarantor of the preservation of the fetus and prevents attempts of spontaneous miscarriage. But sometimes it is produced in too much or not enough quantity. 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 relate to the development of the child at the genome level.
AFP levels can be shown by an AFP test performed after 12 weeks of pregnancy. At this time, the level of alpha-fetoprotein will reach a significant limit. If other numbers are present during the correct decoding, then there are probablyany deviations.
However, an accurate diagnosis based on AFP analysis alone is not possible, as errors occur. Its elevated level may indicate different things:
- multiple pregnancy;
- fetal liver necrosis;
- anencephaly;
- umbilical hernia;
- kidney pathology.
The development of internal organs with an anomaly also leads to an increase in the level of AFP.
Decreased concentration of alpha-fetoprotein may be a sign that:
- has Down's pathology;
- there is a delay in the development of the embryo;
- fetal death occurred.
In some cases, low AFP levels are at risk of miscarriage. And sometimes its content is so low that, based on what the AFP analysis shows (the norm in women or not), doctors conclude that the pregnancy is false.
Abnormal Pregnancy
Any deviations in protein content from normal values are an important criterion for monitoring the progress 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, ultrasound is performed as a control measure. In addition, it is important to check the level of hCG (human chorionic gonadotropin). If all carried outstudies confirm the fact that a child with a high probability of being born with a pathology, the burden of making a responsible decision lies with the woman herself.
What else does AFP content indicate
Not always AFP analysis during pregnancy, decoding is necessary only for expectant mothers. In some cases, this tumor marker is an important study in the diagnosis of any serious disease in adult patients. Normally, the indicator is not more than 10 U / ml. An increase in this level indicates that a malignant tumor has begun to develop in the human body, often with metastases. For more information about 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 condition of the liver, it can be concluded that the presence or absence of chronic alcoholism.
Preparing for analysis
If the doctor has ordered a study such as the analysis of AFP and hCG during pregnancy, little preparation is required. Usually everything goes as with a normal blood draw from a vein. And this means that in the next 5-8 hours you can not eat. In pregnant women, the period should be at least 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 which 10 ml is takenbiomaterial.
And since the procedure is performed on an empty stomach and is difficult, 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 can affect the analysis
In addition to proper preparation, it is important to consider that some factors can distort the analysis of AFP during pregnancy. In this case, the norm is achieved if you follow simple rules. At dinner, it is best to refrain from eating food with different spices, as well as fatty, smoked and fried foods.
Physiotherapeutic procedures such as ultrasound and massage, as well as instrumental methods such as X-ray, MRI, CT scans 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 use should also be delayed. At least until the end of the analysis.
It is also noted that representatives of the Negroid race have a higher concentration of AFP, while it is much lower in the Mongoloid nation. You should also take into account the presence of some endocrine disease like diabetes or viral diseases in the past.
Where can I get tested?
Currently, in any public or private laboratory, you can take the analysis of AFP and hCG during pregnancy. The norm will be known more precisely if experiencedspecialists who own the research methodology, and the necessary equipment. The cost of such an analysis ranges from 300 to 600 rubles.
If you need to go through such a study, you should not try to understand the result yourself, only a specialist should deal with decoding. 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. However, data monitoring should be carried out in the same laboratory using the same reagent.
Deciphering the analysis and the 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, a study on placental hormones and other diagnostic methods.
Each laboratory uses its own methodology and reagents when analyzing the level of AFP. But at the same time, the units of measurement are designated in all cases the same way: IU / ml or MoM. For example, if AFP and hCG are analyzed during pregnancy, the norm (MoM) is 0.5-2. However, if the laboratory uses other measurements (IU / ml), then the protein level, depending on the gestational age, will change as follows (see table below).
| Week | Value, IU/ml |
| 5th-11th | Under 15 |
| 13-15th | 15-62 |
| 15-19th | 15-95 |
| 20-25th | 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 goes for non-pregnant women.
Indications for conduction
It is recommended that all pregnant women be tested for AFP no later than the 12th week of pregnancy. This is necessary to identify the presence or absence of deviations. And if they are absent, then the process is proceeding normally. But if they are present, the attending physician prescribes a second 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 a pathology inherited. This is especially critical if a woman is pregnant for the first time over the age of 35.
The following situations still need to be taken into account:
- If a woman miscarries while trying to get pregnant.
- Receptionmother before pregnancy or during the initial period of toxic drugs that affect the fetus.
- The presence of any hereditary pathology or mutation at the genetic level in future parents.
Besides this, it is simply necessary to undergo an examination if a woman underwent an X-ray examination at an early stage of bearing a child.
