Deciphering the results of the hCG analysis. In what units is it customary to measure the level of hCG? What is the difference between total hcg and beta
Human chorionic gonadotropin (hCG) is a special hormone that is used to diagnose the presence of pregnancy, the quality of its course and the development of its possible complications. In addition, it is used as a tumor marker to search for malignant neoplasms of embryonic origin in the body.
Many people do not know exactly what hCG is and constantly ask their doctors about it. The molecular structure of a protein consists of two subunits, alpha and beta. The result of the analysis for hCG is based on the establishment of the last fragment of the chain. Total beta-hCG remains a unique protein that can be determined using appropriate reagents.
The process of establishing the concentration of the corresponding hormone is very important in modern medical practice. A blood test for hCG is the most reliable and proven test for stating a pregnancy. Starting from the 6-7th day, the concentration of this biologically active substance begins to increase, reaching its peak at about 11-12 weeks of gestation.
By itself, the analysis of hCG during pregnancy involves the study of two biological fluids from the body. A person can take for diagnosis:
- Blood.
- Urine.
The first option is considered more universal, since it is used to analyze hCG, deciphering the indicators for both men and women. In the second case, testing is relevant only for pregnant women. The hormone, or rather the B fraction of hCG, penetrates the renal barrier and enters the urine, where it is determined 1-2 days later than the analogous substance in the blood. Modern pregnancy tests are based precisely on this mechanism for detecting the hCG norm.
The blood test itself is carried out in vitro (in vitro) by the method of immunochemiluminescent analysis. Testing requires 5 ml of venous blood. The results of the hCG analysis will most often be ready in the region of 24 hours after the collection of biological material.
Deciphering analyzes
Diagnosis of pregnancy, fetal malformations or the occurrence of various complications in the process of bearing a baby is not the only direction in which the hormone is used. It has shown itself to be a good tumor marker for detecting malignant neoplasms with active endocrine function or embryonic origin.
However, it is not enough to donate blood for testing. How to decipher the analysis? This is the question that interests most people, patients or pregnant women who, for one reason or another, undergo appropriate laboratory diagnostics.
It all depends on the purpose for which the diagnosis was carried out. If these studies are deciphered as part of establishing the presence of pregnancy, then they will not coincide with the norms for similar testing for the development of cancer. In any case, the patient's interest in human chorionic gonadotropin should be supported by a qualified assessment of the doctor.
Weekly results of the analysis of hCG in pregnant women
Since most often the decoding of the hCG analysis is carried out precisely in women who are carrying a fetus, it is better to start with this diagnostic method. A fertilized embryo, in the process of attaching to the endometrium and developing in the wall of the uterus, releases large doses of the corresponding hormone. Then the protein is synthesized by the placenta.
HCG 1-5 weeks shows the highest growth activity in the body up to 11-12, after which it gradually decreases. In the blood, using special methods and chemical reactions, b-hCG is determined, the total concentration of this hormone is the sum of both of its fractions. The beta subunit is unique and has characteristic effects on the body. Therefore, it is easier to find it in biological material.
The table below shows the increase in the amount of the hormone each week of pregnancy. The decoding of hCG is usually carried out by a doctor, however, often expectant mothers independently learn to distinguish between the corresponding values:
| Pregnancy period, weeks | HCG indicator, mIU / ml |
| Non-pregnant woman | 0 – 5 |
| Doubtful result | 5 – 25 |
| 3-4 | 25 – 156 |
| 4-5 | 101 – 4870 |
| 5-6 | 1110 – 31500 |
| 6-7 | 2560 – 82300 |
| 7-8 | 23100 – 151000 |
| 8-9 | 27300 – 233000 |
| 9-13 | 20900 – 291000 |
| 13-18 | 6140 – 103000 |
| 18-23 | 4720 – 80100 |
| 23-41 | 2700 – 78100 |
The hCG test, or rather its results, can sometimes differ. Much depends on the capabilities and method of its determination in a particular laboratory. So for example, in the above table, specific units of measurement of protein in the blood are visible. Sometimes there is another indicator - IU / l. They can replace each other. 1 mIU/ml = 1 IU/L.
There are situations when, due to certain features of the work of a particular laboratory, it is necessary to wait for the result of the analyzes longer than usual. This may be due to the workload of the institution itself or the lack of reagents. In any case, the average time to receive final data is 24 hours.
It is also worth noting that the first pregnancy test taken is not always reliable. Due to the individual characteristics of the woman's body, or errors in the work of medical personnel, sometimes it is necessary to undergo the appropriate diagnostics not once, but two or three times. If the second test gave an incorrect result, then it is worth changing the laboratory.
An important feature of the increase in the amount of the hormone in the body of a pregnant woman is that hCG begins to rise actively at 1 or 2 weeks of gestation. Up to week 5, it increases by 2 times every 36 hours, as shown in the table above. If this does not happen, then the doctor has the right to suspect some kind of pathology.
Possible reasons for the increase in the amount of the hormone
HCG results can vary quite a lot. However, if they seriously exceed the indicated norms at a certain gestational age, this may mean the presence of some kind of disorder. In addition, we must not forget that hCG as a tumor marker also plays a serious role, although this is not relevant during pregnancy.
Situations in which analyzes may not meet the standards, but significantly exceed them, are:
- Errors in establishing the actual gestational age and calculated by doctors.
- Prolongation of gestation over 42 weeks.
- early toxicosis. HCG for 1-2 weeks can already significantly exceed normal levels, which will cause the progression of characteristic symptoms.
- Taking medications that contain hCG.
- The presence of a genetic disease in the fetus, requiring more thorough diagnosis.
In all these situations, it is hCG that remains the main marker, the decoding of which should be handled by an experienced qualified doctor. Otherwise, there is a high risk of diagnostic error.
If we talk about the hormone as a tumor marker, then its increase in the blood of non-pregnant women and men may indicate the presence of a malignant neoplasm. Normally, in the absence of gestation, the result of hCG in the range of 0-1 IU / l is considered normal. Perhaps an increase to 5 IU / l, but no more. Otherwise, a number of the following pathologies can be suspected:
- Choriocarcinoma or its recurrence after treatment.
- Bubble drift.
- Seminoma or teratoma of the testicles in men.
- Neoplasms in the digestive tract or lungs.
- Tumors of the uterus, kidneys.
- Abortion a few days ago.
If the hCG result is less than / equal to 1-2 IU / L, then it can be regarded as normal. With significant fluctuations in these indicators, additional diagnostics should be carried out.
Possible causes of a decrease in the amount of the hormone
Since protein is used in medicine as an oncomarker, an indicator of the quality of the course of pregnancy and the presence of its various disorders, it is also worth knowing when the amount of the hormone in the blood can decrease.
Such situations include:
- Attachment of the fetal egg outside the uterine cavity. In such cases, the already 1-week hCG result will immediately be too low, which will make it possible to suspect a problem.
- Frozen pregnancy.
- placental insufficiency.
- High risk of miscarriage. In this state, the interpretation of the results will demonstrate a decrease in the concentration of the hormone up to 50% of its required amount at a given time.
- Fetal death.
In all these cases, the decoded hCG analysis will show too low values, which should definitely alert doctors and cause additional diagnostics with the choice of the appropriate treatment method.
Additional nuances
Despite the seriousness of the above pathologies, it must be understood that deviations in the results of laboratory diagnostics are not always associated only with the presence of a particular disease. Very often, even a simple mistake of the work of the staff can lead to a distortion of the indicators.
Additional factors that can change the concentration of hCG in the blood, but are not pathological conditions, remain:
- Errors in the mechanical delivery of biological material.
- Wrong calculation of the gestational age.
- Irregularity of the menstrual cycle in a woman.
- Untimely attachment of the embryo to the endometrium.
That is why it is always necessary to understand the imaginary end results. In addition, the concentration of hCG in the blood is never the basis for establishing a particular diagnosis. You always need to examine the patient much deeper.
One way or another, a qualified doctor should decipher the results of the tests. Only he will be able to comprehensively assess the condition of a woman or a patient, prescribe appropriate related tests and decide whether it is necessary to choose one or another method of treatment. The main thing is not to panic, but to methodically examine yourself to determine the cause of the fluctuation in test results.
Bibliography
- Clinical guidelines. Obstetrics and gynecology. Savelyeva G.M., Serov V.N., Sukhikh G.T. 2009 Publisher: Geotar-Media.
- Anomalies of labor activity: a guide for physicians. UMO certification for medical education. Podtetenev A.D., Strizhova N.V. 2006 Publisher: MIA.
- Atlas of ultrasound diagnostics in obstetrics and gynecology. Dubile P., Benson K.B. 2009 Publisher: MEDpress-inform.
- Intrauterine infection: Management of pregnancy, childbirth and the postpartum period. UMO certification for medical education. Sidorova I.S., Makarov I.O., Matvienko N.A. 2008 Publisher: MEDpress.
- Clinical guide to contraception. /Translated from English/ Edited by Professor V.N. Prilepskaya - 2009, M.: BINOM Publishing House.
- Ascending infection of the fetoplacental system. Glukhovey B.I. 2006, Publisher: MEDpress-inform.
What is human chorionic gonadotropin (hCG)?
Human chorionic gonadotropin is a special hormone protein that is produced by the membranes of the developing embryo during the entire period of pregnancy. HCG supports the normal development of pregnancy. Thanks to this hormone, the processes that cause menstruation are blocked in the body of a pregnant woman and the production of hormones necessary to maintain pregnancy increases.
An increase in the concentration of hCG in the blood and urine of a pregnant woman is one of the earliest signs of pregnancy.
The role of hCG in the first trimester of pregnancy is to stimulate the formation of hormones necessary for the development and maintenance of pregnancy, such as progesterone, estrogens (estradiol and free estriol). With the normal development of pregnancy in the future, these hormones are produced by the placenta.
Chorionic gonadotropin very important. In the male fetus, chorionic gonadotropin stimulates the so-called Leydig cells, which synthesize testosterone. Testosterone in this case is simply necessary, as it contributes to the formation of the genital organs according to the male type, and also has an effect on the adrenal cortex of the embryo. HCG consists of two units - alpha and beta hCG. The alpha component of hCG has a similar structure to the units of the hormones TSH, FSH and LH, and the beta hCG is unique. Therefore, in the diagnosis, laboratory analysis of b-hCG is of decisive importance.
Small amounts of human chorionic gonadotropin are produced by the human pituitary gland even in the absence of pregnancy. This explains the fact that in some cases very low concentrations of this hormone are determined in the blood of non-pregnant women (including women during menopause) and even in the blood of men.
Permissible levels of hCG in the blood of non-pregnant women and men
How does the human chorionic gonadotropin level change during pregnancy?
With the normal development of pregnancy, hCG is determined in the blood of pregnant women from about 8-11-14 days after conception.The level of hCG rises rapidly and, starting from the 3rd week of pregnancy, doubles approximately every 2-3 days. The increase in the concentration in the blood of a pregnant woman continues until about 11-12 weeks of pregnancy. Between 12 and 22 weeks of pregnancy, the concentration of hCG decreases slightly. From 22 weeks until delivery, the concentration of hCG in the blood of a pregnant woman begins to increase again, but more slowly than at the beginning of pregnancy.
By the rate of increase in the concentration of hCG in the blood, doctors can determine some deviations from the normal development of pregnancy. In particular, in an ectopic pregnancy or miscarriage, the rate of increase in the concentration of hCG is lower than in a normal pregnancy.
Accelerating the rate of increase in the concentration of hCG may be a sign of hydatidiform mole (chorionadenoma), multiple pregnancy, or fetal chromosomal diseases (for example, Down's disease).
There are no strict standards for the content of hCG in the blood of pregnant women. HCG levels at the same gestational age can vary significantly from woman to woman. In this regard, single measurements of hCG levels are not very informative. To assess the development of pregnancy, the dynamics of changes in the concentration of chorionic gonadotropin in the blood is important.
Days since last period | Gestational age | Nomes of the hCG level for this period mU / ml |
human chorionic gonadotropin chart
Norms of human chorionic gonadotropin in blood serum
Note!
In the last table, the weekly norms are given for the terms of pregnancy "from conception" (and not for the terms of the last menstruation).
Anyway!
The above figures are not a standard! Each laboratory can set its own standards, including the weeks of pregnancy. When evaluating the results of the hCG norm by week of pregnancy, you need to rely only on the norms of the laboratory where you were tested.
Tests to determine the level of hCG
To determine the level of hCG, various laboratory blood tests are used that can detect pregnancy for a period of 1-2 weeks.The analysis can be taken in many laboratories in the direction of a gynecologist and independently. No special preparation for the blood test is required. However, before you get a referral for a test, be sure to tell your doctor about all the medications you are taking, as some medications can interfere with the test results. The analysis is best taken in the morning, on an empty stomach. For a higher reliability of the test, it is recommended to exclude physical activity on the eve of the study.
By the way, home express pregnancy tests are also built on the principle of determining the level of hCG, but only in the urine, not in the blood. And it should be said that compared to a laboratory blood test, this one is much less accurate, since the level in the urine is two times lower than that in the blood.
A laboratory test for determining pregnancy in the early stages is recommended to be carried out no earlier than 3-5 days of delayed menstruation. The blood test for pregnancy can be repeated after 2-3 days to clarify the results.
To identify fetal pathology in pregnant women, an analysis for chorionic gonadotropin is taken from the 14th to the 18th week of pregnancy. However, in order for the diagnosis of possible fetal pathologies to be reliable, it is necessary to pass more than one blood test for hCG. Together with hCG, the following markers are given: AFP, hCG, E3 (alpha-fetoprotein, human chorionic gonadotropin, free estriol.)
Serum levels of AFP and CG during physiological pregnancy
| Pregnancy period, weeks | AFP, average level | AFP, min-max | CG, medium level | CG, min-max |
|---|---|---|---|---|
| 14 | 23,7 | 12 - 59,3 | 66,3 | 26,5 - 228 |
| 15 | 29,5 | 15 - 73,8 | ||
| 16 | 33,2 | 17,5 - 100 | 30,1 | 9,4 - 83,0 |
| 17 | 39,8 | 20,5 - 123 | ||
| 18 | 43,7 | 21 - 138 | 24 | 5,7 - 81,4 |
| 19 | 48,3 | 23,5 - 159 | ||
| 20 | 56 | 25,5 - 177 | 18,3 | 5,2 - 65,4 |
| 21 | 65 | 27,5 - 195 | ||
| 22 | 83 | 35 - 249 | 18,3 | 4,5 - 70,8 |
| 24 | 16,1 | 3,1 - 69,6 |
Can an hCG test “make a mistake” in determining pregnancy?
HCG levels that are out of the norm for a particular week of pregnancy can be observed if the gestational age is incorrectly established.Laboratory analyzes can be wrong, but the probability of error is very small.
Decryption
Normally, during pregnancy, the level of human chorionic gonadotropin gradually increases. During the 1st trimester of pregnancy, the level of b-hCG rises rapidly, doubling every 2-3 days. At 10-12 weeks of pregnancy, the highest level of hCG in the blood is reached, then its content begins to slowly decrease and remains constant during the second half of pregnancy.An increase in beta-hCG during pregnancy can occur with:
- multiple pregnancies (the rate increases in proportion to the number of fetuses)
- toxicosis, gestosis
- maternal diabetes
- fetal pathologies, Down syndrome, multiple malformations
- incorrect gestational age
- taking synthetic gestagens
- production of hCG by the pituitary gland of the examined woman testicular tumors
tumor diseases of the gastrointestinal tract
neoplasms of the lungs, kidneys, uterus
hydatidiform mole, recurrence of hydatidiform mole
chorioncarcinoma
taking hCG medications
the analysis was done within 4–5 days after the abortion, etc.Usually chorionic gonadotropin is elevated if the test was performed on the 4-5th day after the abortion or due to the use of hCG preparations.
Low hCG in pregnant women, it may mean an incorrect setting of the term for determining pregnancy or be a sign of serious violations:
- ectopic pregnancy
- non-developing pregnancy
- fetal growth retardation
- the threat of spontaneous abortion (reduced by more than 50%)
- chronic placental insufficiency
- true miscarriage
- fetal death (in the II-III trimester of pregnancy).
Whatever the result of the analysis for hormones during pregnancy is, remember that only a qualified doctor can give the correct decoding, determining which hCG is the norm for you in combination with the data obtained by other examination methods.
Video. Prenatal Screening - HCG
Among the list of tests that a woman must undergo during pregnancy or just planning to become a mother, you can find the abbreviation "hCG" but what is it? This analysis shows the amount of human chorionic gonadotropin, let's consider it in more detail.
HCG, what is it?
HCG is a hormone that has a protein nature and consists of two fractions - alpha and beta. Of clinical interest is the beta fraction of the hormone, since alpha is similar in structure to other female hormones. And beta is unique - this makes it easy to determine it in the blood.
The biological role of hCG in the body of a pregnant woman:
1. The hCG hormone contributes to the preservation of the corpus luteum during pregnancy and the production of progesterone by it before the full work of the placenta begins. This contributes to the preservation of pregnancy and the bearing of a healthy child. Without enough hormone, motherhood will not take place. The placenta begins to synthesize female hormones on its own from about 16 weeks.
2. Chorionic gonadotropin helps a woman get used to the onset of pregnancy, stimulating the adrenal glands to produce glucocorticoids, making the expectant mother more resistant to stress. Carrying a child is stressful for the female body, especially in the early stages.
3. When the placenta has already formed (at week 16), hCG provides good nutrition and development, preventing premature detachment.
4. In medicine, the introduction of a hormone through injections is practiced. It stimulates ovulation and promotes conception in women. Using such injections in men, you can achieve an increase in the level of sex hormones and improve the quality of sperm.
Norms of hCG indicators in women
It is not difficult to take an analysis for the level of hCG: this is an ordinary blood test from a vein. The result of the analysis is usually issued on the same day or the next.
Deciphering the result of the analysis done for hCG lies on the shoulders of the doctor. It is difficult to understand the abundance of numbers and meanings on your own. However, you should remember how the hormone level changes depending on the duration of pregnancy and know the average values in non-pregnant women (see table).
Important! Norm indicators may vary, depending on the laboratory that performed the analysis.
In girls and men, hCG levels should be 0-5 mU / ml. This amount is so small that a test performed to determine hCG in the urine does not respond to it and will show one strip.
From the first days of pregnancy, the level of hCG will increase. This happens until 11–12 weeks, when the highest value of the hormone is noted. Further, gonadotropin gradually decreases and in the last stages of pregnancy shows approximately the same value.
Increasing hCG during pregnancy
With the onset of fertilization, the level of human chorionic gonadotropin increases. This happens literally immediately after fertilization.
The quantitative composition of the hormone is steadily growing and reaches a maximum by week 11, and then declines. In the second half of pregnancy, the indicators stabilize and change little.
Express tests sold at a pharmacy to determine pregnancy can change color when hCG is found in the urine. Although the method is not as revealing as a blood test for hCG, it is still quite accurate. In a non-pregnant woman, the result will be negative, while a pregnant woman will be able to find out about the presence of pregnancy before other signs appear.
A blood test for chorionic gonadotropin is able to give an answer after 7-10 days from the moment the egg and sperm meet. Obtaining the results of an hCG analysis at such an early date makes it possible to control the course of pregnancy almost from the very moment of fertilization.
Carefully monitoring the levels of the most important pregnancy hormone will help prevent pregnancy complications, including its termination. This is true for women who unsuccessfully tried to experience the joy of motherhood, as well as for late-born or women with a burdened obstetric history.
If the level of hCG in a woman "in an interesting position" exceeds the norm, then this may be evidence of the following processes in the body:
- When carrying two or three fruits.
- Diseases of the fetus at the chromosomal level (Down's syndrome).
- Diabetes mellitus in the anamnesis of a pregnant woman.
- Severe course of gestosis during pregnancy.
- The use of female hormones from the outside.
Decrease in hCG during pregnancy
Gonadotropin levels may decrease in the following cases:
- With an atypical location of the fetal egg (tubal, or).
- If the fetus lags behind in its development.
- With a frozen pregnancy.
- In violation of blood circulation between the baby and the placenta or between the placenta and the uterus.
- If .
- When overridden.
Increasing hCG in women and men
A blood test for the hCG hormone in a non-pregnant woman or in men provides important diagnostic information. There were cases when men, for fun, did an analysis using a pregnancy test and received two strips.
On the one hand, this seems to be ridiculous and impossible, but on the other hand, this is not a reason for jokes. Chorionic gonadotropin can appear in the body of men and women with the development of a malignant tumor.
These are the so-called hormone-producing tumors that can form in the organs of the reproductive system, lungs, and stomach.
Deciphering the analysis of hCG, table
For a doctor, deciphering the result of an hCG analysis carries a lot of information during pregnancy. By analyzing the blood counts for the quantitative content of the hormone, the doctor will determine the gestational age with high accuracy, and will also be able to suspect an ectopic pregnancy, some flow pathologies, an impending miscarriage, etc.
This will help to take measures to save the desired child and take actions aimed at preventing complications in the expectant mother and her baby.
Of course, only the level of this hormone is not diagnosed. More research is needed. But it is the amount of the main hormone of motherhood that indicates a possible problem and directs the doctor in the right direction to identify this problem.
| Gestational age | Mean value, mIU/ml | Limit values, mIU/ml |
| 2 weeks | 150 | 50-300 |
| 3-4 weeks | 2000 | 1500-5000 |
| 4-5 weeks | 20000 | 10000-30000 |
| 5-6 weeks | 50000 | 20000-100000 |
| 6-7 weeks | 100000 | 50000-200000 |
| 7-8 weeks | 80000 | 40000-200000 |
| 8-9 weeks | 70000 | 35000-145000 |
| 9-10 weeks | 65000 | 32500-130000 |
| 10-11 weeks | 60000 | 30000-120000 |
| 11-12 weeks | 55000 | 27500-110000 |
| 13-14 weeks | 50000 | 25000-100000 |
| 15-16 weeks | 40000 | 20000-80000 |
| 17-21 weeks | 30000 | 15000-60000 |
The results of the analysis for hCG made in the laboratory can be indicated in different units of measurement: mU / ml, U / lm, IU / ml, mIU / ml - this is the same. remember, that The rate of results in each laboratory may vary slightly!
Human chorionic gonadotropin is a hormone that begins to be actively produced in a woman's body after the fertilization of the egg and the onset of such a wonderful condition as pregnancy.
HCG is made up of subunits alpha and beta. Of these two components, the beta unit is not only unique, but also has a number of special properties. In addition, it is free beta-hCG that is the basis of the tests that are used to determine the onset of conception in the early stages. There are 145 amino acids in free beta-hCG, thanks to which this unit is constantly unique.
Human chorionic gonadotropin carries out a huge number of appointments in the body of a woman. The beta unit, as well as the alpha unit, begins to be produced after the direct fertilization of the egg, its subsequent transportation and attachment to the endometrium located on the walls of the uterus.
When the patient is not in position, an increase in the concentration of this hormone can signal the presence of the following pathological conditions:
- tumor neoplasms that affect the concentration of hormones in the body;
- conception occurred, but there are significant deviations from the correct development of the baby, while the villi of the placenta begin to actively grow, forming bubbles that are filled with liquid inside;
- a woman uses a complex of medicinal drugs containing human chorionic gonadotropin;
- Recently, a manipulation of the artificial termination of pregnancy was performed.
In the normal state, this hormone is present in a small amount not only in the fair sex, but also in the stronger sex. When pregnancy occurs, there is an increase in the concentration of gonadotropin in the blood plasma a week after the female germ cell has been fertilized. In the fluid secreted by the kidneys, an increase in hCG occurs 10 days after the onset of pregnancy, it is during this period that the active production of the hormone in the body of the expectant mother begins.
Functions of beta hCG
This subunit is extremely necessary during the period of bearing a baby due to the fact that it is she who is responsible and provides a connection between the baby and mother. The main functions of the free beta substance are:
- Activation of the working capacity of the corpus luteum, which is essential to maintain the development and nutrition of the fetus until the period until the full formation of the placenta occurs. Under the influence of hCG, the required amount of progesterone is produced, which in turn ensures the maintenance of normal conditions for the progression of pregnancy.
- Stimulates the production of sex hormones such as estrogens and androgens.
- It activates the synthesis of all hormones in the body of the fetus, and especially testosterone in boys, because it is he who is responsible for the full formation of sexual characteristics in male children.
Free beta-hCG is the main regulator of all processes occurring during the period of gestation. The amount of the hormone in the blood proportionally increases depending on the period of gestation. During the first trimester, or rather, from 2 to 5 weeks, the number of the beta-hCG indicator begins to actively increase almost 2 times every 36 hours. The largest number during pregnancy was recorded from 6 to 8 weeks. After that, the indicator begins to gradually decrease.
What is the analysis for?
For the most accurate and correct determination of the onset of pregnancy, women are prescribed a blood test to determine the free chorionic hormone. This test is considered the most accurate and informative. Modernly developed reagents and technologies make it possible to accurately detect up to hundredths of the amount of the hormone in the blood plasma.
Experts advise taking an analysis to determine the concentration of hCG during the various trimesters of bearing a baby in the same laboratory. Such manipulation is necessary in order for the results obtained to be error-free. For laboratory research, an immunochemiluminescent (ICLA) method is used - this is an analysis based on the immune reactions of an antigen with an antibody.
The analysis is used in the following cases:
- to determine the course of pregnancy (normal, ectopic, frozen);
- in the absence of menstruation for several months in a row;
- violations of the functionality of the placenta;
- the presence of hormonal tumor formations;
- fetal malformations.
In males, this analysis helps to diagnose testicular cancer. To determine the state of pregnancy during the first months of gestation, an analysis is made for the content of free beta-hCG. In the case when it is necessary to determine the presence of any developmental abnormalities, the delivery of the total chorionic hormone is prescribed.
Norms of beta hCG
To decipher the result, you need to contact your doctor. Personal characteristics of the body can affect the results of the test. In the normal state, the amount of this hormone in the body of female and male representatives should not exceed 10 units / l. In the event of pregnancy, the concentration of hCG begins to increase rapidly and can reach more than 500 IU / l.
The indicator of beta-hCG, depending on the week of bearing the baby, can be in the range:
- 2 weeks - 50-300 IU / ml;
- 3-4 - 1500-5000 IU / ml;
- 4-5 - 10000-30000 IU / ml;
- 5-6 - 20000-100000 IU / ml;
- 6-7 - 50000 - 200000 IU / ml;
- 7-8 - 40000-200000 IU / ml;
- 8-9 - 35000-140000 IU / ml;
- 10-11 - 30000-120000 IU / ml;
- 11-12 - 27500-110000 IU / ml;
- 13-14 - 25000-100000 IU / ml;
- 15-16 - 20000-80000 IU / ml;
- 17-21 - 15000-60000 IU / ml;
- 26-38 - 3000-15000 IU / ml.
When the hCG hormone falls into this range, there is no reason to worry. The analysis must be taken in the morning on an empty stomach.
Deviations from the norm
An excessive increase in the number of free hCG beta units very often indicates the presence of tumor neoplasms in the stomach, intestines and genitals. In this situation, the concentration of this hormone will significantly exceed the established ranges of norms for pregnant women. In addition, the correspondence of whole molecules and beta units will help determine whether the tumor belongs to a benign or malignant formation. In this regard, this analysis has become very popular in recent times.
In the presence of deviations from the norm in the human body, various pathological processes and conditions begin to develop.
If the patient is not pregnant, but has an increased amount of beta-hCG, then the following changes may occur in her body:
- complete or partial molar pregnancy;
- gestational trophoblastic tumor;
- destructive cystic skid;
- malignant tumor of the ovaries;
- cancer of the reproductive organs;
- osteogenic sarcoma.
All of the above pathological changes require immediate therapy due to the fact that they provoke the occurrence of concomitant abnormalities that can lead to an unforeseen situation. In this case, you need to seek help from a doctor as soon as possible, who will prescribe a set of measures to treat the problem that has arisen.
Deviation in a pregnant woman
During the various trimesters of bearing a baby, the beta-chorionic hormone indicator can be either increased or decreased. When the concentration of hCG is lowered, then this may be due to such changes in the body of the expectant mother as:
- incorrect establishment of the period of development of the baby;
- attachment of the embryo outside the uterus, or rather in the fallopian tube;
- intrauterine fetal death;
- deviations from the normal development of the child;
- placental insufficiency;
- premature interruption of gestation;
- pathological attachment of a fertilized egg.
An increased number of beta-hCG in the blood plasma indicates such processes as:
- simultaneous development of several embryos;
- early toxicosis resulting from various factors;
- the presence of diabetes and its exacerbation;
- nephropathy in a pregnant woman, which is accompanied by an increase in blood pressure;
- a complication of the course of the gestation of the embryo, characterized by swelling, convulsions and other unpleasant symptoms.
An increased concentration of free beta-chorionic hormone may be associated with the use of medications, the main component of which is this hormone.
When the course of pregnancy occurs without any pathologies, then the amount of the hormone will be 1.099 MoM. When the concentration of the hormone is in the range of 1.3 -1.489 MoM, there is a threat of spontaneous abortion. An indicator of 1.151 - 1.183 MoM indicates a developmental delay and the possible presence of malformations of the embryo in the mother's body. The concentration of the hormone in the range of 1.361 MoM indicates kidney damage.
Additional tests
To establish an accurate diagnosis, one analysis for hCG is not enough. To do this, you need to undergo a comprehensive examination and pass a number of necessary tests. Only after that the doctor will be able to determine the deviation and prescribe the appropriate treatment.
Most often, a screening test is prescribed for pregnant women. It can be used to detect the presence of chromosomal abnormalities in the development of the embryo. This diagnosis is carried out during the first trimester from 11 to 13 weeks. The beta-hCG indicator helps determine whether a child has a disease such as Down syndrome.
A positive result indicates an increased risk of the presence of this disease. In this regard, the patient must necessarily pass an additional set of tests to confirm or, conversely, refute the diagnosis.
In case of a negative result, a screening test is additionally carried out during the second trimester to completely exclude the presence of Down syndrome and other chromosomal diseases.
When the beta-hCG unit is within the normal range, then the patient does not need to worry, since the pregnancy proceeds without pathologies and her unborn child develops fully. In the case of deviations, a woman is often prescribed a set of medications that will help stabilize and normalize the amount of the hormone. In order to control this indicator, you need to regularly take tests and undergo all the studies recommended by the attending gynecologist.
- one of the main hormones that regulate the functions of the sex glands. It performs a number of important tasks in the body of a pregnant woman, helping to maintain the right concentration of other hormones and survive the stress that is gestation.
Given the important role of chorionic gonadotropin, it is not surprising that the analysis of its concentration in the blood is one of the main ones in monitoring pregnancy. The units of measurement for hCG in the test results of several different laboratories may differ, therefore, in order to correctly interpret the results, it is important to know the relationship between them.
Why is hCG so important?
To understand why the content of chorionic gonadotropin is one of the main markers of a healthy pregnancy (especially in the first trimester), it is necessary to understand its properties and effects on the body.
Along with other gonadotropic hormones (luteinizing and follicle-stimulating), as well as thyrotropin (TSH), hCG consists of an α- and β-subunit. The structure of the hCG β-subunit distinguishes it from the listed hormones (the α-subunit is a homologous similar structural component in FSH and TSH). During pregnancy, it is a determining factor that allows you to set the concentration of this particular hormone due to a specific reaction to the subunit.
In its properties, hCG resembles both other gonadotropic hormones at once. However, despite the ability to bind to both types of receptors, the luteinizing properties significantly prevail over the stimulation of the follicle. In this capacity, hCG is significantly superior to the usual pituitary luteinizing hormone: it is thanks to its high activity that the corpus luteum, which normally exists for the last two weeks of the menstrual cycle, is preserved until the placenta develops enough to produce estrogen and progesterone.
Under the influence of chorionic gonadotropin, the corpus luteum produces a lot, which is required for the normal course of pregnancy. HCG also stimulates the production of estrogens, without which the activation of progesterone, weak androgens and glucocorticoids is impossible, which reduce the immune response to a half-foreign body and avoid miscarriage.
The role of hCG in the body of a pregnant woman explains the dynamics of hormone production: up to 10-12 weeks, its amount is steadily increasing, because. For the normal bearing of the fetus, more and more progesterone is required. After the placenta matures and the secretion of all the hormones necessary for pregnancy by its tissues begins, the need for the existence of the corpus luteum and its intensive stimulation disappears, so the concentration of hCG decreases.
Given all of the above, an excess or deficiency of chorionic gonadotropin in pregnant women indicates pathologies or diagnostic errors (more likely in the early stages of gestation).
The concentration of chorionic gonadotropin during pregnancy
Human chorionic gonadotropin is considered a placental hormone, despite the fact that in the absence of pregnancy, a small amount of it (not higher than 5 mIU / ml, according to some reports up to 6.15) is produced by the pituitary gland. During pregnancy, the rate of beta hCG is several orders of magnitude higher than this figure.
The normal content of hCG in the blood by week of pregnancy;
| Number of weeks (from conception) | Normal concentration of hCG, mIU / ml |
| Up to 2 | 25-156 |
| 2-3 | 100-4870 |
| 3-4 | 1110-31500 |
| 4-5 | 2560-82300 |
| 5-6 | 23100-151000 |
| 6-7 | 27300-233000 |
| 7-11 | up to 291000 |
| 11-16 | 6140-103000 |
| 16-21 | 4720-80100 |
| 21-39 | 2700-78100 |
Normally, after the cessation of the functioning of the corpus luteum, the concentration of chorionic gonadotropin gradually decreases, but in the third trimester of pregnancy, a repeated, less intense peak in the level of the hormone can be observed.
Previously, in medical practice, this phenomenon was considered one of the variants of the norm. Today, experts are more wary of the peak: an increase in the level of hCG after 11 weeks often indicates pathologies that threaten the health of the mother (trophoblastic disease), or placental insufficiency. The latter is often observed in the Rh-conflict of the organism of the pregnant woman and the fetus.
To monitor the health of the fetus, as well as to determine the presence of certain types of cancerous tumors, an analysis of the content of free β-hCG is used.
| week of pregnancy | The concentration of free hCG, mIU / ml |
| Screening in the first trimester | |
| 9 | 502-4109 |
| 10 | 549-3864 |
| 11 | 370-2775 |
| 12 | 285-2734 |
| 13 | 302-2441 |
| Screening in the second trimester; | |
| 14 | 189-1690 |
| 15 | 125-1319 |
| 16 | 99-1064 |
| 17 | 71-911 |
| 18 | 82-709 |
The concentration of free hCG can be indicated in nanograms per milliliter. The ratio of honey and mIU to ng is given below.
In men and in the absence of pregnancy in women, the level of unbound beta-subunit of gonadotropin does not exceed 43 mIU / ml (the maximum level of free hCG is 2 ng / ml).
The table below is indicative. It is up to the supervising physician to interpret the results, as these norms are average and may not be suitable for a particular pregnant woman due to special circumstances (some chronic diseases, multiple pregnancy, etc.).
Causes of low and high levels of hCG
Possible causes of elevated hCG levels in expectant mothers can be:
- multiple pregnancy (the level of hormone concentration is proportional to the amount);
- preeclampsia;
- severe early toxicosis;
- diabetes mellitus in a pregnant woman;
- prolonged gestation;
- discrepancy between the estimated and actual terms of pregnancy;
- taking hCG preparations or gestagens;
- chromosomal abnormalities in the fetus.
In non-pregnant women, an increased level of hCG in the blood may be associated with the onset of menopause (the normal value increases to 9.5 mIU / ml), an analysis less than 5 days after the abortion, and trophoblastic diseases (molar mole, etc.).
Normally, after the birth of a child, chorionic gonadotropin is not detected in the urine, and its concentration in the blood quickly drops to normal values (0-6.15 mIU / ml). If this does not happen even after 42 days after birth, gynecologists talk about trophoblastic pathology.
The reason for the increase in the level of gonadotropin can also be the presence of a cancerous tumor in the intestines, kidneys, and lungs. In men, an increased amount of hCG in the blood can also be associated with seminoma and testicular teratoma, in women with a hormone-producing neoplasm in the uterus.
A low level of hCG, unlike an elevated one, is only dangerous. Possible causes of the phenomenon may be:
- ectopic localization of the fetus;
- delayed fetal development;
- true overgrowth;
- risk of miscarriage;
- antenatal fetal death (when monitored in the 2nd-3rd trimester of pregnancy);
- chronic placental insufficiency (for example, due to the Rhesus conflict of the mother and fetus).
Of great importance is not only the result, but also the dynamics of hCG growth. For example, when it doubles on average 2 times a week, while normally the concentration of gonadotropin doubles every 2 days. With the threat of a miscarriage, the level of hCG drops rapidly (on average, by more than 50% of the normal value).
Features of the analysis for the level of hCG
Units
Measurement of the concentration of chorionic hormone is carried out in mIU / ml (international milliunits per milliliter), mU / ml or in mass units - nanograms per milliliter of biomaterial. Indicators honey and mIU are equivalent to each other. To convert ng / ml to generally accepted units, it is necessary to multiply the result obtained by 21.28.
Thus, 21.28 mU/ml = 21.28 mIU/ml = 1 ng/ml.
Result confirmation
From about 500 mIU / ml of hCG, the fetus can be detected on a transvaginal ultrasound. Early ultrasound diagnosis is used to clarify the location of the fetus, because. the concentration of placental gonadotropin also increases during ectopic pregnancy.
Biomaterial
Blood and urine can be used to study the level of hCG concentration. Home test strips and inkjet testers are less accurate than venous blood tests, but are cheap and easy to use. The sensitivity of the tests is indicated on the package.
Most of them show a positive result when the hCG concentration exceeds 25 mIU / ml, i.e. about 2 weeks after conception. More expensive tests are able to report pregnancy earlier - as early as 7-10 days after the fertilization of the egg.
However, in the early stages, experts advise resorting to a blood test, because. it will be possible to talk about a truly positive or negative result only after a few days after the delay.
Application in combination with other studies
Elevated levels of hCG in pregnant women may indicate fetal chromosomal diseases (most likely Down syndrome). To clarify the result, a comprehensive screening is carried out. In the first trimester, it includes the analysis of free β-hCG and PAPP-A (plasma protein A associated with pregnancy). A low protein level indicates a high risk of severe chromosomal abnormalities. In the second trimester, screening includes the study of three biochemical markers (hCG, alphafetoprotein and estriol-A).
In the absence of pregnancy, the hCG test can be used in combination with tests for tumor markers to determine cancerous growths.
How to get accurate results
The correctness of the result largely depends not only on the reagents and the correct work of the laboratory staff, but also on the preparation of the patient (patient) for the study. There are several rules that will minimize the error:
- venous blood analysis should be carried out strictly, if possible before 10 am;
- on the eve of the study, it is undesirable to eat fatty foods, drink alcohol and play sports;
- within 2-3 hours before blood sampling, it is necessary not to smoke or even drink water, and also to exclude stress;
- the patient or the patient must warn the laboratory assistant about all the drugs taken, especially hormonal ones;
- it is undesirable to donate biomaterial after X-ray, ultrasound, massage, physiotherapy and examinations.
This is important: for monitoring pregnancy, the dynamics of the increase in the level of hCG is very important, therefore, tests should be taken at the same time of day, under unchanged nutritional conditions.