Human chorionic gonadotropin (hCG), also known as the “pregnancy hormone,” is a hormone produced by cells in the placenta during pregnancy. The hormone can be found in the blood and urine of a pregnant woman and is the basis of many pregnancy tests.
What is hCG?
hCG(Human Chorionic Gonadotropin) or simply HCG (Chorionic Gonadotropin) is the so-called “pregnancy hormone”. The hCG hormone is produced by the cells of the chorion (the membrane of the embryo) immediately after it attaches to the wall of the uterus.
That is, the presence of chorionic tissue in the body means the woman is pregnant. But sometimes an increase in the concentration of hCG may indicate not the occurrence of pregnancy, but the presence of a tumor in the body. Based on the level of hCG in the body, one can judge the presence multiple pregnancy, as well as about the nature of the pregnancy.
The most important function of hCG is to maintain pregnancy. In the first trimester, hCG plays an important role in stimulating the production of hormones that are necessary for the development and maintenance of pregnancy, such as progesterone and estrogens.
Another important task of hCG is to maintain the viability of the corpus luteum and stimulate ovulation.
HCG consists of two subunits - α (alpha) and β (beta). The alpha component has the same structure as the alpha component, FSH (follicle stimulating hormone) and LH (luteinizing hormone), and the beta subunit of human chorionic gonadotropin (b-hCG) is unique. Therefore, the presence of hCG in the blood (or urine) is determined precisely by this beta subunit (hence the term “b-hCG”).
An hCG test is prescribed in the following situations:
in women
- diagnostics early dates pregnancy;
- monitoring pregnancy over time;
- detection of amenorrhea;
- exception ectopic pregnancy;
- assessment of the completeness of induced abortion;
- if there is a threat of miscarriage;
- suspicion of an undeveloped pregnancy;
- diagnosis of tumors;
in men
- diagnosis of testicular tumors.
General hCG during pregnancy
Synonyms: HCG, hCG, b-hCG, beta-hCG, total b-hCG, human chorionic gonadotropin, Human Chorionic gonadotropin, HCG, total b-HCG, b-HCG, beta HCG.
A blood test for b-hCG is the most reliable method for determining pregnancy in the early stages. The hCG hormone appears in the female body already from 6–8 days from the moment of fertilization. But it is better to take the test no earlier than the first day of missed menstruation, so that the hCG concentration is already sufficient to confirm pregnancy.
Pregnancy can also be determined using home rapid tests based on the determination of human chorionic gonadotropin in the urine. But in urine the required level of this hormone is achieved several days later than in the blood.
During a normal pregnancy, the level of hCG in the blood doubles approximately every 2 days and reaches its maximum concentration at 10-11 weeks of pregnancy, after which it begins to slowly decrease. During multiple pregnancies, the level of the hCG hormone increases in proportion to the number of fetuses.
Free beta hCG during pregnancy
Synonyms: free beta-hCG, free hCG, free hCG, free beta subunit of hCG, free beta subunit of human chorionic gonadotropin, free HCG, free beta HCG, fb-HCG, free Human Chorionic gonadotropin.
Free b-hCG is used for early prenatal diagnosis of congenital pathologies of the fetus (I and II trimesters).
In the first trimester of pregnancy from 10 to 14 weeks (optimally at 11-13 weeks), a so-called “double test” is performed, which, in addition to free b-hCG, also includes the determination of PAPP-A (Pregnancy-associated Plasma Protein-A) – pregnancy-associated plasma protein A. At the same time, it is also necessary to do an ultrasound.
In the second trimester (16-18 weeks) a “triple test” is performed. Free b-hCG (or total hCG), AFP (alphafetoprotein) and free estriol (E3) are determined.
Interpretation of the analysis for hCG during pregnancy
It must be kept in mind that different laboratories report different hCG levels, which depend not only on the units of measurement, but also on the sensitivity of the methods used to determine hCG levels. Therefore, when assessing the results of the analysis it is necessary to rely only on the standards of the laboratory where the analysis was done.
To determine the dynamics of hCG, the analysis must also be taken in the same laboratory, because comparing the results of different laboratories is not entirely correct.
In the results, free beta-hCG is indicated not only in conventional units, but also in the MoM coefficient. This is done to make it convenient for doctors to evaluate test results, since the MoM norm for all biochemical markers is the same - from 0.5 to 2 (for a singleton pregnancy).
Each woman's hCG levels may change differently during pregnancy. One specific result is not indicative; it is necessary to consider the hCG level over time.
In most cases, if the hCG level is below 5 mU/ml, then it is considered that there is no pregnancy. When the hCG level is above 25 mU/ml, it can be assumed that pregnancy has occurred.
Increased hCG levels during pregnancy can occur in multiple pregnancies (the hCG level increases in proportion to the number of fetuses), incorrectly determined gestational age, early toxicosis of pregnancy, diabetes mellitus in the mother. An increase in hCG in the results is one of the signs of Down syndrome (but only in conjunction with deviations of other markers). On later pregnancy, a high level of hCG may indicate postmaturity.
Low level HCG during pregnancy usually signals problems with pregnancy. If hCG stops increasing, then most often this indicates a frozen or ectopic pregnancy. If the hormone level decreases by more than 50% of the normative value, there is a threat spontaneous abortion. Also, low hCG can be a sign of chronic placental insufficiency, true post-term pregnancy, fetal death (in the II-III trimesters).
But low hCG levels during pregnancy do not always indicate problems. For example, the gestational age (the number of completed weeks of pregnancy from the first to the last menstrual period) may be incorrect due to late ovulation or incorrect menstrual cycle data provided by the mother.
Sometimes found increase in hCG hormone in non-pregnant women and men. This result may occur when taking medicines containing hCG after an abortion (usually within a week), and can also occur with chorionic carcinoma, hydatidiform mole and their relapses, with neoplasms of the gastrointestinal tract, kidneys, uterus and other organs, with testicular tumors.
HCG units
Laboratories may report hCG test results during pregnancy in different units of measurement, for example, mIU/ml, mIU/ml, mIU/ml, ng/ml and others.
Typically, hCG levels are measured in special units - mIU/ml– milli international units in 1 milliliter (in international designation – mIU/ml– milli-international units per millimeter).
honey/ml means the same as mIU/ml, only U are just units, and IU are international. That is, 1 mU/ml = 1 mmU/ml.
ng/ml (ng/ml)– these are nanograms per milliliter.
1 ng/ml * 21.28 = 1 mU/l
With the onset of pregnancy, the expectant mother will have to undergo a lot of research and undergo many tests. Most often, women are prescribed a general examination of urine and blood. However, the results of such diagnostics cannot confirm or refute a new interesting position. This article will focus on beta-hCG. You will find out what this substance is and why it is formed. It is also worth mentioning at what time you need to take a beta-hCG test. In medicine, there are generally accepted norms for this substance in a woman’s blood in different periods pregnancy.
Beta HCG
This substance secreted by the fertilized egg and placenta. It appears in the blood expectant mother the very next day after implantation. At the same time, conventional pregnancy tests still show a negative result. This is due to the fact that the amount of beta-hCG in the urine is much less than in the blood. That is why, if you want to quickly find out about your pregnancy, you should take a blood test.
During the period from the thirteenth to the eighteenth week, a range of this hormone can be observed in the blood of the expectant mother ranging from 6140 to 103,000 units. After this (up to approximately the 24th week of embryo development), the level of human chorionic gonadotropin is 4720-80 100 IU/ml.
Third trimester
At this stage, hormone levels are very rarely measured. However, there are generally accepted standards that are oriented towards when it is necessary to conduct research. So, in the period from the 23rd to the 40th week, 2700-78,100 units of the substance are found in the blood of the expectant mother.
Remember that during multiple pregnancies the amount of human chorionic gonadotropin may be slightly higher.
Possible pathologies
Is there a certain rate of beta-hCG for possible pathologies? Unfortunately, medicine has not yet established certain data. All due to the fact that the pathology can begin at different dates and under various conditions. Also, the body of each expectant mother is individual and cannot react to possible difficulties in the same way.
- When the hormone level reaches its norm before a certain week (usually the 5th-6th). After this, a sharp decline in the substance occurs, and the analysis shows negative values.
- An ectopic pregnancy is characterized by the fact that the norm of beta-hCG is not achieved. The hormone level is growing, but very slowly and significantly lags behind the established values.
- HCG levels are much higher than normal during hydatidiform mole. However, during an ultrasound, an embryo with a heartbeat is not detected.
- If the expectant mother suffers from diabetes, then the amount of beta-hCG may also exceed normal values.
Can a normal pregnancy not meet the established hCG standards?
It also happens that the fetus develops absolutely normally, but the amount of human chorionic gonadotropin in the woman’s blood is significantly higher or lower than normal. Why is this happening?
Most often, this situation arises in the very early stages. At the same time, the woman cannot accurately name the date of conception. If the gestational age is set incorrectly, then the hormone levels may diverge from the established standards. Most often, ultrasound diagnostics helps clarify the situation. During an ultrasound, the doctor can accurately determine the duration of pregnancy (up to one day).
Summing up and concluding the article
So, you now know what levels of human chorionic gonadotropin are allowed during pregnancy. Remember not to rely too much on established numbers. Each woman's body is individual and can react differently to a new position. Do not take into account the numbers that your friends had at one time or another. Some doctors say that the normal level of beta-hCG may vary depending on the gender of the unborn child.
If you get a bad result, you should repeat the analysis. Often there is a laboratory error or incorrect comparison with standards. When decoding data, always pay attention to the established study center values. They may be very different from other laboratories. Also, the result can be displayed in different units of measurement. All this greatly influences the obtained values. To clarify the situation, contact your gynecologist and follow all instructions given. Have an easy pregnancy!
) is a hormone actively produced by the external tissues of the embryo in pregnant women. This substance is found in the body of both women and men, but in small quantities. Its increase occurs only during pregnancy in the fair sex.
HCG is divided into two types - alpha hormone and beta hormone. Today we will talk in more detail about the essence of the latter, research on its level in the body and normal indicators. Interesting? Then be sure to read the presented material to the end.
As noted above, human chorionic gonadotropin is a rather specific hormone in the human body. In men and non-pregnant women, it is practically not observed in the urine and is found in extremely small quantities in the blood. Active secretion begins in pregnant girls. The substance is produced by the external tissues of the embryo, and its increased level in urine and blood indicates precisely the fact of pregnancy.
Increased production of the hormone begins within a few days after fertilization of the egg. The structure of hCG contains proteins, amino acids and other biounits that are essential for the fetus. The most extensive division of the hormone is carried out according to its specific properties. The alpha and beta subunits of the hormone are isolated here.
Beta HCG is the most important view a substance that begins to be secreted by the tissues of the embryo earliest and in large quantities.
It contains about 150 amino acids and other biological structures. Due to the unique structure and a number of specific properties, it is beta-hCG that helps detect pregnancy in women at the earliest stages of its course. You can determine the fact of fertilization:
- through a blood test already on days 5-7 of pregnancy
- through a urine test on days 10-12 (all pregnancy tests sold in pharmacies are based on the determination of beta-hCG)
In men and non-pregnant women, the amount of the hormone in the body is small. Its elevated level indicates either pregnancy in the fairer sex, or serious pathologies of the body in both sexes. Normally, an increase in beta-hCG is observed only in women during pregnancy. This should be remembered.
When is the test scheduled?
The beta-hCG test is one of the basic tests for pregnant women. Depending on individual characteristics In a specific case, such a study can be prescribed to a girl from 3 to several dozen times during the period of gestation.
In addition, the determination of beta-hCG plays an important role in terminating pregnancy. This study helps to track exactly how a woman’s body reacts to the fact of interrupted gestation and whether she needs help.
In situations not related to pregnancy, the hormone level is determined in for preventive purposes. Quite rarely, a profile analysis for beta-hCG is prescribed to people if they suspect:
- malfunctions of the organs responsible for the secretion of hormonal substances
- improper use of medications that affect the body's hormonal levels
Hormone levels in non-pregnant women and men
As noted earlier, the diagnosis of beta-hCG is carried out using. The examination procedure is identical for pregnant women, men and non-pregnant women. To determine the level of the hormone, a person just needs to visit a diagnostician and submit biomaterial for analysis. The study does not require specialized training.
It is enough to come to the examination hungry and avoid physical and psycho-emotional stress on the eve of the examination. Many doctors also recommend:
- Warn the diagnostician about the medications you are taking before the analysis, if any.
- Show the specialist the results of previous diagnostics, if any.
- For pregnant women, undergo examination in different trimesters of pregnancy in the same laboratory in order to obtain the most reliable and accurate results.
- Blood is taken from the ulnar vein of the left arm for testing. As a rule, analysis results are prepared within 3-5 days.
Normal indicators Beta-hCG levels differ between pregnant and non-pregnant women. Thus, for unfertilized women, the norm is considered to be up to 5-6 medical units per milliliter of blood (mU/ml), and for men - up to 3-4. As for pregnant women, their normal values are within wider limits. We'll talk about them further.
Normal beta-hCG levels in pregnant women
The norm of beta-hCG in pregnant women is a highly flexible concept. Normal indicators during pregnancy are different type and depend on its duration. Whether the test results are normal for a particular patient or not is always determined by the specialist observing her.
The average norms look like this:
| Week of pregnancy | Beta-hCG level, mU/ml |
| 1-2 | 25-300 |
| 2-3 | 1 500-5 000 |
| 3-4 | 10 000-30 000 |
| 4-5 | 20 000-100 000 |
| 5-6 | 50 000-200 000 |
| 6-7 | 50 000-200 000 |
| 7-8 | 20 000-200 000 |
| 8-9 | 20 000-100 000 |
| 9-10 | 20 000-95 000 |
| 11-12 | 20 000-90 000 |
| 13-14 | 15 000-60 000 |
| 15-25 | 10 000-35 000 |
| 26-38 | 10 000-60 000 |
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 state as pregnancy.
HCG consists of subunits such as 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 tests that are used to determine the onset of conception in the early stages. Free beta-hCG contains 145 amino acids, thanks to which this unit is constantly unique.
Human chorionic gonadotropin carries out a huge number of purposes in a woman’s body. The beta unit, like 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 may signal the presence of the following pathological conditions:
- tumors that affect the concentration of hormones in the body;
- conception has occurred, but there are significant deviations from the correct development of the baby, while the placental villi begin to actively grow, forming bubbles that fill with liquid inside;
- a woman uses a complex of medications containing human chorionic gonadotropin;
- Recently a procedure for artificial termination of pregnancy was performed.
In a normal state, this hormone is present in small quantities not only in the fair sex, but also in the stronger sex. When pregnancy occurs, the concentration of gonadotropin in the blood plasma increases a week after the female reproductive cell has been fertilized. In the fluid secreted by the kidneys, an increase in hCG occurs 10 days after pregnancy; it is during this period that active production of the hormone begins in the body of the expectant mother.
Functions of beta-hCG
This subunit is extremely necessary during the period of bearing a baby due to the fact that it is responsible for and ensures the connection between the baby and mother. The main functions of free beta substance are:
- Activation of the performance of the corpus luteum, which is extremely necessary to maintain the development and nutrition of the fetus until the placenta is fully formed. 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.
- Activates the synthesis of all hormones in the fetal body, and especially testosterone in boys, because it 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 increases proportionally depending on the period of gestation. During the first trimester, or more precisely, from 2 to 5 weeks, the level of beta-hCG begins to actively increase almost 2 times every 36 hours. The greatest number during pregnancy was recorded from 6 to 8 weeks. After this, the indicator begins to gradually decrease.
Why do you get tested?
For the most accurate and correct definition Once pregnancy occurs, women are prescribed a blood test to determine 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 hormone in blood plasma.
Experts advise taking a test to determine the concentration of hCG during different trimesters of pregnancy in the same laboratory. Such manipulation is necessary so that the results obtained are error-free. For laboratory research, the immunochemiluminescent (CHL) 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;
- dysfunction of the placenta;
- the presence of hormonal tumors;
- fetal malformations.
In males, this test helps diagnose testicular cancer. To determine the state of pregnancy during the first months of gestation, an analysis is performed for the content of free beta-hCG. In cases where it is necessary to determine the presence of any developmental abnormalities, a test for total chorionic hormone is prescribed.
Beta-hCG norms
To decipher the result, you need to contact your doctor. Personal characteristics of the body may influence the test results. In a normal state, the amount of this hormone in the body of female and male representatives should not exceed 10 U/l. If pregnancy occurs, the concentration of hCG begins to increase rapidly and can reach more than 500 U/l.
The beta-hCG level, depending on the week of pregnancy, can be within the following 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 within these limits, there is no reason to worry. The test must be taken in the morning on an empty stomach.
Deviations from the norm
An excessive increase in the number of free beta units of hCG very often indicates the presence of tumors in the stomach, intestines and genitals. In this situation, the concentration of this hormone will significantly exceed the established normal ranges for pregnant women. In addition, the correspondence of whole molecules and beta units will help determine whether a tumor is benign or malignant. Due to this, this analysis has become very popular recently.
If there are deviations from the norm, various pathological processes and conditions begin to develop in the human body.
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 hydatidiform mole;
- malignant ovarian tumor;
- reproductive organ cancer;
- osteogenic sarcoma.
All of the pathological changes described above require immediate treatment 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.
Deviation in a pregnant woman
During the various trimesters of bearing a baby, the level of beta-chorionic hormone can be either increased or decreased. When the concentration of hCG is reduced, this may be due to such changes in the body of the expectant mother, such as:
- incorrect determination of the baby’s developmental period;
- attachment of the embryo outside the uterus, or rather in the fallopian tube;
- intrauterine fetal death;
- deviations from normal development child;
- placental insufficiency;
- premature termination of pregnancy;
- pathological attachment of a fertilized egg.
An increased amount of beta-hCG in the blood plasma indicates processes such as:
- simultaneous development of several embryos;
- early toxicosis arising as a result of various factors;
- the presence of diabetes mellitus and its exacerbation;
- nephropathy in a pregnant woman, which is accompanied by increased blood pressure;
- a complication of gestation of an embryo, characterized by swelling, cramps 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 pregnancy occurs without any pathologies, the amount of the hormone will be 1.099 MoM. When the hormone concentration is in the range from 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 defects of the embryo in the mother’s body. A hormone concentration within 1.361 MoM indicates kidney damage.
Additional tests
To establish an accurate diagnosis, one hCG test is not enough. To do this, you need to undergo a comprehensive examination and pass a number of necessary tests. Only after this the doctor will be able to determine the deviation and prescribe appropriate treatment.
The most common screening test 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 level helps determine whether a child has a disease such as Down syndrome.
A positive result indicates an increased risk of having this disease. In this regard, the patient must undergo 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 normal limits, the patient does not need to worry, since pregnancy proceeds without pathologies and its unborn child while fully developing. If there are 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 studies recommended by your gynecologist.
Description
Determination method Enzyme immunoassay.
Material under study Blood serum
Home visit available
Specific pregnancy hormone.
Glycoprotein is a dimer with a molecular weight of about 46 kDa, synthesized in the syncytiotrophoblast of the placenta. HCG consists of two subunits: alpha and beta. The alpha subunit is identical to the alpha subunits of the pituitary hormones TSH, FSH and LH. The beta subunit (β-hCG), used for the immunometric determination of the hormone, is unique.
The level of beta-hCG in the blood already on days 6 - 8 after conception makes it possible to diagnose pregnancy (the concentration of beta-hCG in the urine reaches the diagnostic level 1 - 2 days later than in the blood serum).
In the first trimester of pregnancy, hCG ensures the synthesis of progesterone and estrogens necessary to maintain pregnancy by the corpus luteum of the ovary. HCG acts on the corpus luteum like luteinizing hormone, that is, it supports its existence. This occurs until the fetus-placenta complex acquires the ability to independently form the necessary hormonal background. In a male fetus, hCG stimulates Leydig cells, which synthesize testosterone, which is necessary for the formation of male genital organs.
HCG synthesis is carried out by trophoblast cells after embryo implantation and continues throughout pregnancy. During normal pregnancy, between 2 and 5 weeks of pregnancy, the β-hCG content doubles every 1.5 days. The peak concentration of hCG occurs at 10 - 11 weeks of pregnancy, then its concentration begins to slowly decrease. During multiple pregnancies, the hCG content increases in proportion to the number of fetuses.
Reduced concentrations of hCG may indicate an ectopic pregnancy or threatened abortion. Determination of hCG content in combination with other tests (alpha-fetoprotein and free estriol at 15 - 20 weeks of pregnancy, the so-called “triple test”) is used in prenatal diagnosis to identify the risk of fetal developmental abnormalities.
In addition to pregnancy, hCG is used in laboratory diagnostics as a tumor marker for tumors of trophoblastic tissue and germinal cells of the ovaries and testes that secrete human chorionic gonadotropin.
Early diagnosis of pregnancy: determination of hCG levels
What is hCG?
HCG (human chorionic gonadotropin) is a special pregnancy hormone that is important indicator development of pregnancy and its deviations. Human chorionic gonadotropin is produced by the cells of the chorion (the membrane of the embryo) immediately after its attachment to the wall of the uterus. Based on a blood test for human chorionic gonadotropin, the doctor determines the presence of chorionic tissue in the body, and therefore the onset of pregnancy in a woman.
When can a test be performed to determine hCG levels?
Determining the level of human chorionic gonadotropin in the blood is the most reliable method for determining pregnancy in the early stages. Human chorionic gonadotropin appears in a woman’s body 5-6 days after fertilization. A common rapid pregnancy test, which every woman can use at home, is also based on the determination of human chorionic gonadotropin in the urine, but the required level of this hormone in the urine to diagnose pregnancy is achieved several days later.
In the absence of any pathology, in the first weeks of pregnancy the level of the hormone doubles every 2 days, and its maximum concentration is reached by 10-11 weeks of pregnancy. After week 11, the hormone level gradually decreases.
An increase in the level of human chorionic gonadotropin during pregnancy can occur with:
multiple births;
toxicosis, gestosis;
maternal diabetes;
fetal pathologies, Down syndrome, multiple developmental defects;
incorrectly determined gestational age;
taking synthetic gestagens, etc.
Elevated values can also be seen within a week when tested after an abortion procedure. A high level of the hormone after a mini-abortion indicates a progressive pregnancy.
Low levels of human chorionic gonadotropin during pregnancy may indicate incorrect timing of pregnancy or be a sign of serious disorders, such as:
ectopic pregnancy;
non-developing pregnancy;
delay in fetal development;
threat of spontaneous abortion;
fetal death (in the II-III trimester of pregnancy).
Determining the level of human chorionic gonadotropin is part of a triple test study, the results of which can be used to judge the presence of certain abnormalities in fetal development, but an accurate diagnosis cannot be made. The study only allows us to identify women at risk. In this case, women will need to undergo serious additional examination.
What is the role of the hCG hormone in the human body?
In addition to establishing the fact of pregnancy, by quantifying the level of this hormone, one can judge the nature of the course of pregnancy and the presence of multiple pregnancies.
The most important task of human chorionic gonadotropin is to maintain the pregnancy itself. Under its control, the synthesis of the main pregnancy hormones occurs: estrogen and progesterone. In the first trimester, until the placenta is fully formed (up to 16 weeks), human chorionic gonadotropin maintains the normal functional activity of the corpus luteum, namely the production of progesterone.
Another important function of human chorionic gonadotropin is to stimulate ovulation and maintain the viability of the corpus luteum.
When does a doctor order a hCG test?
In addition to diagnosing early pregnancy, human chorionic gonadotropin is determined by:
in women -
to detect amenorrhea;
eliminating the possibility of ectopic pregnancy;
to assess the completeness of induced abortion;
for dynamic monitoring of pregnancy;
if there is a threat of miscarriage and suspicion of an undeveloped pregnancy;
for the diagnosis of tumors - chorionepithelioma, hydatidiform mole;
for prenatal diagnosis of fetal malformations;
for men -
for the diagnosis of testicular tumors.
How to take a blood test for the hCG hormone?
The independent laboratory INVITRO offers laboratory testing to determine the level of human chorionic gonadotropin.
The test is taken by taking blood from a vein, preferably in the morning and on an empty stomach. A laboratory test is recommended to be carried out no earlier than 4-5 days of missed menstruation, and can also be repeated after 2-3 days to clarify the results. To identify fetal pathology in pregnant women, it is recommended to take the test from 14 to 18 weeks of pregnancy.
In a comprehensive diagnosis of fetal malformations, it is also recommended to take tests to determine the following markers: AFP (alpha-fetoprotein), E3 (free estriol), and also do an ultrasound.
Limits of determination: 1.2 mU/ml-1125000 mU/ml
Preparation
It is preferable to take blood in the morning on an empty stomach, after 8-14 hours of overnight fasting (you can drink water), it is acceptable during the day 4 hours after a light meal.
On the eve of the study, it is necessary to exclude increased psycho-emotional and physical activity (sports training), drinking alcohol, smoking an hour before the test.
The sensitivity of the method in most cases makes it possible to diagnose pregnancy already on the first or second day of delayed menstruation, but due to individual differences in the rate of β-hCG synthesis in women, it is better to conduct the study no earlier than 3-5 days of delayed menstruation in order to avoid false negative results. In case of doubtful results, the test should be repeated twice with an interval of 2-3 days. When determining the completeness of removal of an ectopic pregnancy or abortion, a β-hCG test is carried out 1-2 days after surgery to exclude a false-positive result.
Interpretation of results
Interpretation of research results contains information for the attending physician and is not a diagnosis. The information in this section should not be used for self-diagnosis or self-treatment. The doctor makes an accurate diagnosis using both the results of this examination and the necessary information from other sources: medical history, results of other examinations, etc.
Units of measurement in the INVITRO laboratory: honey/ml.
Alternative units of measurement: U/l.
Unit conversion: U/l = mU/ml.
Reference values
Pregnant women
| Gestational age, weeks from conception | HCG level, honey/ml |
| 2 | 25 - 300 |
| 3 | 1 500 - 5 000 |
| 4 | 10 000 - 30 000 |
| 5 | 20 000 - 100 000 |
| 6 - 11 | 20 000 - > 225 000 |
| 12 | 19 000 - 135 000 |
| 13 | 18 000 - 110 000 |
| 14 | 14 000 - 80 000 |
| 15 | 12 000 - 68 000 |
| 16 | 10 000 - 58 000 |
| 17 - 18 | 8 000 - 57 000 |
| 19 | 7 000 - 49 000 |
| 20 - 28 | 1 600 - 49 000 |
Values ranging from 5 to 25 mU/ml do not confirm or refute pregnancy and require re-examination after 2 days.
Increased hCG levels
Men and non-pregnant women:
- chorionic carcinoma, recurrence of chorionic carcinoma;
- hydatidiform mole, relapse of hydatidiform mole;
- seminoma;
- testicular teratoma;
- neoplasms of the gastrointestinal tract (including colorectal cancer);
- neoplasms of the lungs, kidneys, uterus, etc.;
- the study was carried out within 4 - 5 days after the abortion;
- taking hCG drugs.
Pregnant women:
- multiple pregnancy (the level of the indicator increases in proportion to the number of fetuses);
- prolonged pregnancy;
- discrepancy between the actual and established gestational age;
- early toxicosis of pregnant women, gestosis;
- maternal diabetes;
- chromosomal pathology of the fetus (most often with Down syndrome, multiple fetal malformations, etc.);
- taking synthetic gestagens.
Decrease in hCG levels
Pregnant women. Alarming changes in level: discrepancy with the gestational age, extremely slow increase or no increase in concentration, progressive decrease in level, more than 50% of the norm:
- ectopic pregnancy;
- non-developing pregnancy;
- threat of interruption (hormone levels decrease progressively by more than 50% of normal);
- chronic placental insufficiency;
- true post-term pregnancy;
- antenatal fetal death (in the II - III trimesters).
False negative results (non-detection of hCG during pregnancy):
- the test was carried out too early;
- ectopic pregnancy.
Attention! The test has not been specifically validated for use as a tumor marker. HCG molecules secreted by tumors can have both a normal and altered structure, which is not always detected by the test system. Test results should be interpreted with caution and cannot be taken as absolute evidence of the presence or absence of disease when compared with clinical findings and other examination results.
