Free beta-hCG: characteristics of the hormone, norm and deviation. The norm of the beta subunit of human chorionic gonadotropin and deviations from it. How does hCG differ from beta?

Human chorionic gonadotropin is one of the most important hormones in female body, which ensures normal development of the fetus, as well as protection from abortion during early stages. the membranes of the embryo. The substance is the main diagnostic marker to determine that a girl is expecting a baby.

It speaks about the quality of the pregnancy, as well as the appearance of any deviations in its development.

General information

Free hCG is not bound to proteins. Its level is determined using laboratory tests. Free and bound hCG together make up the overall indicator of the hormone’s condition.

In general, hCG consists of two components: alpha and beta subunits. It is the second element that has specific qualities. It is the basis of pregnancy tests. Its different concentrations in urine indicate different degrees of fetal development. Beta hCG always remains unique, that is the difference between it and the alpha subunit. It contains 145 amino acids.

The presented hormone performs various functions in the female body. Free hCG, like general hCG, appears after the egg has already been fertilized and attached to the uterine endometrium. If a woman is not pregnant, then the appearance of the hormone indicates the following disorders:

  • the patient has a tumor that affects hormone levels;
  • happened to a woman hydatidiform mole;
  • recently had an abortion;
  • The patient is taking medications containing hCG.

This hormone plays a huge role in the human body (it can also be present in small quantities in men), although this most often indicates the development of pathology.

If a woman is pregnant, then the first increase in the amount of hCG in the blood is observed already 6–8 days after fertilization of the egg. It is detected in urine already 9–10 days after conception. At this time, active production of the hormone begins.

Main functions of the beta subunit during pregnancy

This substance provides a connection between maternal and child's body. It performs the following functions:

  • activates the work of the corpus luteum, which supports the development and nutrition of the embryo until the formation of the placenta. Under the influence of hCG, the necessary dose of progesterone is produced, which maintains normal conditions for the continuation of pregnancy;
  • promotes the production of estrogen and androgen by the ovaries;
  • stimulation of the synthesis of necessary hormones already in the body of the unborn baby. This is especially true for the production of testosterone, which will be responsible for the formation of male sexual characteristics.

Free hCG is considered the main regulator of the pregnancy process. The amount of beta subunit in the blood depends on its duration. For example, from the second to the fifth week, the concentration doubles every 36 hours. The maximum amount appears already at 6–8 weeks. Gradually the concentration slowly decreases.

Why is a free hormone test necessary?

Today, testing the level of the beta subunit is considered the most accurate and correct for establishing pregnancy. Thanks to modern reagents and technologies, the amount of this component can be determined with an accuracy of hundredths.

You can also perform a pregnancy test at home using highly sensitive products. However, a blood test is considered more accurate than a urine test. Moreover, changes in the amount of hCG appear in it later. Although conception can be determined already on the first day of delayed menstrual bleeding.

All tests to determine hCG levels at all stages of pregnancy must be taken in the same laboratory. The research method is immunochemiluminescent.

The test is prescribed to determine:

  • normal, or ;
  • amenorrhea;
  • the presence of fetal malformations: Down syndrome;
  • hormonally active neoplasms;
  • placental insufficiency.

In men, testicular cancer is diagnosed in this way. The process of bearing a child is also periodically monitored. To diagnose pregnancy, beta hCG is taken during the first trimester, and total hCG levels are examined to determine any malformations. There is an opinion that even changes in meteorological conditions can affect the amount of the hormone, but it does not depend on the circadian rhythm.

The analysis is carried out regardless of how far along the pregnant woman is, regardless of gynecological history or previous diseases. The determining parameter is not the presence of relatives with genetic pathologies. This study is always carried out in pregnant women.

Normal values ​​of the substance

An experienced specialist should interpret the results of the study, taking into account all the accompanying circumstances. Individual characteristics of the body can also affect the study. Normally, women (not pregnant) and men have 0–10 U/l in their bodies. If conception is confirmed, then the amount of hCG increases sharply - more than 500 U/l.

It is also necessary to consider the features of changes in the amount of the hormone depending on the week of pregnancy:

Gestation period, weeks Level, IU/ml
2 50–300
3–4 1500–5000
4–5 10000–30000
5–6 20000–100000
6–7 50000–200000
7–8 40000–200000
8–9 35000–140000
9–10 32500–130000
10–11 30000–120000
11–12 27500–110000
13–14 25000–100000
15–16 20000–80000
17–21 15000–60000
26–38 3000–15000

If the hCG level falls within these parameters, there is nothing to worry about. The test must be performed in the morning on an empty stomach. There are no restrictions on food, except for the recommendations of the treating gynecologist and therapist. You just need to refrain from smoking half an hour before blood sampling, as well as from stressful situations.

International standards do not determine the norms of hCG in the blood during pregnancy. They depend on the chosen research technique and the reagents used in a particular laboratory.

Deviations from the norm in the absence of pregnancy

The beta subunit of hCG is considered an excellent tumor marker for tumors of the gastrointestinal tract, as well as reproductive organs. The hormone values ​​in this case will greatly exceed the norm normal for the corresponding stage of pregnancy. In addition, the ratio of the whole molecule and the beta subunit makes it possible to diagnose the type of neoplasm. This is why analysis has gained such popularity in the last decade.

If the hCG norm is violated, a person may have some health problems. This applies not only to women, but also to men. If there is no pregnancy, but the hormone level exceeds the norm, then this indicates the following pathological conditions:

  • complete or partial hydatidiform mole;
  • trophoblastic neoplasms;
  • invasive hydatidiform mole;

  • ovarian choriocarcinoma;
  • cancer of the ovaries, testicles, bladder;
  • osteosarcoma.

All these problems are very serious and can pose a threat not only to health, but also to human life. You should not delay treatment; an immediate consultation with a doctor will help determine the cause of the disorder, as well as possible ways to treat the pathology.

Deviation from the norm during pregnancy

During pregnancy, the rate of free beta hCG can also be lowered or increased. In the first case, the indicator indicates the following problems:

  • incorrect determination of the embryo development period;
  • ectopic or frozen pregnancy (the increase in hormone levels occurs more slowly than usual);
  • delay physical development baby (insufficient amount of hCG does not allow the synthesis of a normal amount of progesterone, so the embryo lacks nutrients);
  • chronic failure of the placenta;
  • fetal death or threatened miscarriage;
  • improper attachment of the fruit egg, which requires emergency surgical intervention specialists.

A decrease in hCG levels does not always indicate problems. Sometimes this indicates an incorrect pregnancy due to late ovulation or incorrect information about the menstrual cycle.

If hCG increases excessively, a woman may have the following health problems:

  • development of multiple pregnancy;
  • toxicosis, which may have different causes;
  • development diabetes mellitus or its progression;
  • the presence of fetal malformations;
  • complications of pregnancy: preeclampsia, gestosis.

An increase in hormone levels may also indicate that the patient is taking medications that contain hCG. All deviations from the norm require mandatory and immediate medical intervention. Otherwise, the baby will not be able to develop fully.

HCG beta subunit level table for normal pregnancy and pathology.

It is impossible to make a definitive diagnosis based solely on testing the beta subunit of hCG. The research must be comprehensive and comprehensive. Each symptom or deviation from the norm must be checked using tests. Only after comments from a specialist should any measures be taken.

Features of screening in the first trimester

The presented study makes it possible to determine the presence of chromosomal abnormalities in fetal development at an early stage. For example, this diagnostic method is used to identify Down syndrome. Screening is carried out at 11–13 weeks. It is the analysis of the free beta subunit that makes it possible to more accurately determine the disease.

The test can be positive or negative. In the first case, we can talk about a high risk of developing the syndrome in the fetus. Therefore, the woman is prescribed additional tests: amniocentesis and chorionic villus biopsy. If the test is negative, then to confirm the absence of a genetic disorder, you need to additionally undergo screening in the second trimester.

If the free beta subunit of hCG is normal, then there is no need to worry, regardless of the hormonal status. Taking medication regularly will help correct the situation. healthy image life. Human chorionic gonadotropin is a special hormone. It is present in normal quantities not only in women, but also in men’s bodies. Periodic checking of its quantity allows you to detect deadly diseases in time and begin their treatment.

During routine examinations, do not forget about the need to determine the free beta subunit of hCG, the norm of which is known to any attending physician. This indicator gives a complete picture of a woman’s hormonal state. And also, with the help of the free beta subunit of hCG beta, doctors can obtain information about the course of pregnancy for both a young woman in labor and an older woman.

Nowadays, there are many different laboratory tests that help identify various changes occurring in our body. The most long-awaited change for most women is pregnancy. Previously, pregnancy could be suspected by appearance, taste preferences and other signs, but today it is detected by determining beta hCG in the patient’s blood or urine.

What is hCG

HCG (human chorionic gonadotropin or "pregnancy hormone") is a hormone that is produced by the cells of the membrane of the embryo (chorion) after its implantation into the mucous membrane of the uterine cavity. HCG is an important criterion indicating the course of pregnancy and embryo development.


A few days after fertilization of the egg, the embryo is a small bubble, the walls of which consist of actively dividing cells. Some of them gradually transform into an embryoblast, from which the child directly develops; the remaining cells form a trophoblast, with the help of which the embryo attaches to the endometrium (the inner lining of the uterus). Gradually, the trophoblast degenerates into the chorion.


The chorion (the membrane of the embryo) is a kind of intermediary between the body of the child and the mother. It is responsible for the nutrition and formation of the baby, and also produces hCG, which affects both the child and the woman, promoting a favorable pregnancy. It is the presence of this hormone in the blood that makes it possible to detect pregnancy in the early stages.

Functions of hCG and its significance

The main role of hCG– providing conditions for a successful pregnancy through multilateral effects on the fetus and the woman’s body. Human chorionic gonadotropin activates the functions of the corpus luteum, which secretes progesterone, which maintains the optimal state of the endometrium, ensuring reliable implantation of the fetus and its nutrition. In each menstrual cycle, the corpus luteum exists for at least 2 weeks and, in the absence of fertilization, resolves. HCG not only helps preserve this endocrine gland, but also maintains its activity throughout pregnancy. HCG also stimulates the formation of estrogens and androgens by the ovaries, promotes the full development of the chorion, which, growing, transforms into the placenta.

Alpha and beta hCG

The hCG hormone is a complex compound of protein and carbohydrates and consists of two subunits: alpha and beta. Alpha hCG is identical to the analogue unit of other tropic hormones: luteinizing hormone, follicle-stimulating hormone and thyroid-stimulating hormone. Beta hCG is unique in structure and determines the specificity of the hormone, making it possible to detect its presence in biological fluids (urine, blood) and identify pregnancy or other conditions of the body.


The level of beta hCG in the blood helps determine the duration of pregnancy. As a rule, it appears 6-8 days after fertilization, immediately after implantation of the embryo. Normally, the concentration of beta hCG increases by 2 times every two days in proportion to the number of fetuses (this applies to multiple pregnancies), reaching its maximum at 10-12 weeks. Then the concentration of the hormone begins to decrease. This is due to the fact that in the second trimester the placenta begins to secrete on its own required amount estrogen and progesterone for the normal course of pregnancy, and does not depend on the state of the corpus luteum. Therefore, during this period, the main role of beta hCG is to stimulate the formation of testosterone in the embryo for the full development of the external genitalia.


Throughout pregnancy, the level of beta hCG concentration changes, so this hormone serves not only to diagnose a new situation, but also to determine the nature of the course of the entire period and identify disorders.

Indications for prescribing tests for beta hCG

Determination of hormone concentration is necessary in the following situations:

Diagnosis of pregnancy;
Monitoring the progress of pregnancy over time;
Amenorrhea;
Ectopic pregnancy;
Evaluation of the results of induced abortion;
Risk of miscarriage;
Suspicion of a frozen pregnancy;
Early diagnosis fetal malformations;
Neoplasms.
The test is sometimes performed on men to detect testicular tumors.

How to test for beta hCG

You can get tested in public or private institutions, including the IVF Center clinic in Vladimir. As a rule, to determine the level of beta hCG, venous blood is taken - this is the most reliable way definitions of pregnancy. The hormone appears in the blood serum 6-8 days after fertilization.


Beta hCG testing can be done at home. To do this, you need to purchase express tests to determine pregnancy, which are based on the interaction of the hormone and antibodies to it. The morning urine sample is used for the study. It should be noted that the required concentration of hCG in the urine is achieved several days later than in the blood.

Timeframe for analysis

A study to determine the level of beta hCG is carried out several times throughout the entire period of pregnancy. The first time the analysis is prescribed when registering with antenatal clinic to establish the fact of conception and its timing. The second time, to determine the nature of the course of pregnancy, the analysis is done at 10-12 weeks simultaneously with ultrasound screening. After all, it is during this period that beta hCG levels are maximum.


If the results of the second study are poor, then the test is ordered again at 16-18 weeks, and, if necessary, the hormone level is monitored throughout the entire period of pregnancy.

Beta hCG norms

Beta hCG levels are quite arbitrary and depend on the duration of pregnancy, the number of fetuses, medicines, as well as on the method of determining the hormone, reagents and laboratory. Therefore, having received the results of the study, it is necessary to take their transcript from the institution in which it was carried out. And it is advisable to take repeated tests in the same laboratory to obtain objective data.


In the first trimester, the maximum values ​​of beta hCG in the blood are determined, which make it possible to determine multiple pregnancies and fetal malformations. In the second trimester, the hormone level is reduced; in the third, studies are carried out extremely rarely.

Decoding the analysis results

A negative beta hCG test indicates that there is no pregnancy, but sometimes it can be a false negative because it is done too early.


Increased level beta hCG is determined in the following situations:

Multiple pregnancy;
Toxicosis;
Diabetes;
Fetal malformations (for example, Down syndrome);
Taking certain medications;
Incorrectly determined gestational age;
Post-term pregnancy;
Hydatidiform mole (disease of the fertilized egg and lack of full development of the embryo);
Neoplasms secreting hCG;
The first 4-5 days after an abortion.

A decrease in beta hCG levels is diagnosed when:

Ectopic and frozen pregnancy;
Delayed fetal development;
Threat of miscarriage;
Chronic placental insufficiency;
Post-term pregnancy;
Incorrect stage of pregnancy;
Fetal death in the 2nd-3rd trimester.

In medical practice, exact norms for beta hCG values ​​have not been established for various diseases Therefore, if any pathology is suspected, in addition to hormone analysis, other diagnostic methods should be performed, in particular ultrasound. Very often, pregnancy proceeds completely normally, but the test results indicate an overestimated or underestimated level of the hormone. Most often this occurs during studies at 10-12 weeks. This may be due individual characteristics a woman’s body, a laboratory error, an incorrectly determined gestational age and other conditions.


Therefore, rely only on the results of the beta hCG test if you suspect pathological conditions not worth it. After all, every woman is unique and reacts differently to a new situation. If you get a bad test, don’t despair, you just need to retest and undergo additional examination. It is not recommended to independently decipher the diagnostic results and compare the obtained values ​​with the data of other women; your attending physician will be able to clarify the situation, and only he will make adequate and necessary prescriptions.

HCG, or - a hormone released during pregnancy. HCG is produced in the body of a pregnant woman by the trophoblast. The structure of this hormone is similar to the structure of follicle-stimulating hormone, luteinizing hormone. Moreover, hCG differs from the above hormones in one subunit, which is designated as beta. It is on this difference in the chemical structure of the hormone that the standard pregnancy test and tests performed by doctors are based. The difference is that a standard pregnancy test measures the level of hCG in the urine, while tests prescribed by doctors measure the level of hCG in the blood.

The effect of hCG on a woman’s body

Human chorionic gonadotropin is a hormone that promotes pregnancy. Thanks to its biological action, the function of the corpus luteum is maintained in the woman’s body in the early stages of pregnancy. The corpus luteum synthesizes progesterone, the pregnancy hormone. Against the background of hCG synthesis, the placenta is formed, which subsequently also produces hCG.

HCG analysis - normal

Normal hCG in non-pregnant women and normal hCG in men is 6.15 IU/L.

Free beta hCG is normal

For non-pregnant women, the normal free beta subunit of hCG in venous blood is up to 0.013 mIU/ml. For pregnant women, normal free hCG by week is in mIU/ml:

  • 49.9 at week 11;
  • 40.6 at week 12;
  • 33.6 at week 13;
  • 28.8 at 14 weeks.

HCG norms for DPO

Level of human chorionic gonadotropin by days after ovulation (DPO) in mIU/ml:

  • 12 day - 17 - 199;
  • 13 day - 17 - 147;
  • Day 14 - 33 - 223;
  • 15 day - 33 - 429;
  • Day 16 - 70 - 758;
  • Day 17 - 111 - 514;
  • Day 18 - 135 - 1690;
  • Day 19 - 324 - 4130;
  • Day 20 - 385 - 3279;
  • 21 days - 506 - 4660.

HCG – norms in IU/l and MoM

HCG levels are measured in two units, IU/L and mIU/ml. HCG norm in IU/l by week is:


MoM is the ratio of the hCG level obtained as a result of the study to the median value. 0.5-2 MoM is the physiological norm for pregnancy.

Norms of PAPP A and hCG

Papp alpha is a pregnancy-associated plasma protein. The level of this protein is an important marker for the presence of chromosomal abnormalities in the fetus and for diagnosing the course of pregnancy. The study of this marker is relevant until the 14th week of pregnancy, at later the analysis is uninformative.

PAPP alpha norms by week of pregnancy in Med/ml:

  • 8-9 weeks – 0.17-1.54;
  • 9-10 weeks – 0.32-2.42;
  • 10-11 weeks – 0.46-3.73;
  • 11-12 weeks – 0.79-4.76;
  • 12-13 weeks – 1.03-6.01;
  • Week 13-14 - 1.47-8.54.

Antibodies to hCG are normal

Antibody cells that destroy the hCG hormone can form in the blood of a pregnant woman. This process is the main cause of miscarriage, since in the absence of hCG the hormonal background of pregnancy is disrupted. Normally, there can be up to 25 U/ml of antibodies to hCG in the blood.

hCG (human chorionic gonadotropin)- a special hormone produced by placental cells during pregnancy and consisting of two subunits, α and β. If the α-subunit of hCG is completely identical in structure to the α-subunits of the hormones FSH, TSH and LH, which are constantly present in the female body, then β-hCG is unique in its structure. It is this that makes it possible to diagnose the onset of pregnancy within 6-8 days after conception. The presence of hCG in the body is detected by enzyme immunoassay in blood or urine. Unlike pharmacy tests, which are recommended to be used no earlier than the first day of the delay, a laboratory blood test for pregnancy allows you to find out the result several days before the expected onset of menstruation. The fact is that the diagnostic concentration of hCG is achieved in the blood serum 1-2 days earlier than in the urine. Therefore, a blood test for pregnancy is a more accurate and faster early diagnosis tool. Having completed the study in CITO mode, you can get the result within 2 hours after you donate blood for hCG.

Properties of hCG

HCG is responsible for maintaining the functional activity of the corpus luteum in the first trimester, stimulates the production of estrogens and progesterone necessary to maintain pregnancy, as well as Leydig cells, which are responsible for the synthesis of testosterone in the male fetus. Quantitative indicators of this hormone allow not only to conduct a highly accurate pregnancy test, but also to identify the risk of abnormalities in the development of the placenta and fetus (in combination with tests for alpha-fetoprotein and free estriol).

Norms of hCG indicators

The synthesis of hCG in the body begins from the first day of implantation of the embryo into the uterine wall and continues throughout the entire period of gestation. During normal pregnancy, between 2-5 weeks, the level of β-hCG in the blood serum doubles every 2-3 days and reaches peak values ​​​​in the period from 7 to 11 weeks, after which it gradually decreases.

Indicators in the range of 5-25 mU/ml do not confirm or refute pregnancy, so in such cases it is recommended to re-test for beta-hCG after 2 days. If the dynamics of the quantitative increase in hCG values ​​deviates from the norm, consultation with a qualified doctor is necessary, since an increase or decrease in the level of the “pregnancy hormone” can be due to both individual factors (incorrectly determined gestational age, chronic and past diseases) and more serious complications.

When hCG levels are elevated:

  • multiple pregnancy;
  • maternal toxicosis or gestosis;
  • chronic diseases (diabetes mellitus);
  • taking synthetic gestagens;
  • fetal malformations;
  • hydatidiform mole;
  • hormone-producing tumors in women and men.

When hCG levels are low:

  • chronic placental insufficiency;
  • risk of miscarriage;
  • ectopic pregnancy;
  • delayed fetal development;
  • frozen pregnancy in the II-III trimester;
  • true post-term pregnancy.

No special preparation is required for the study. It is necessary to follow the general requirements for preparation for research.

GENERAL RULES FOR PREPARATION FOR RESEARCH:

1. For most studies, it is recommended to donate blood in the morning, from 8 to 11 o’clock, on an empty stomach (at least 8 hours must pass between the last meal and blood collection, you can drink water as usual), on the eve of the study, a light dinner with a restriction eating fatty foods. For tests for infections and emergency studies, it is acceptable to donate blood 4-6 hours after the last meal.

2. ATTENTION! Special preparation rules for a number of tests: strictly on an empty stomach, after a 12-14 hour fast, you should donate blood for gastrin-17, lipid profile (total cholesterol, HDL cholesterol, LDL cholesterol, VLDL cholesterol, triglycerides, lipoprotein (a), apolipo-protene A1, apolipoprotein B); glucose tolerance test performed in the morning on an empty stomach after 12-16 hours of fasting.

3. On the eve of the study (within 24 hours), avoid alcohol, intense physical activity, and taking medications (in consultation with your doctor).

4. 1-2 hours before donating blood, refrain from smoking, do not drink juice, tea, coffee, you can drink still water. Avoid physical stress (running, quickly climbing stairs), emotional excitement. It is recommended to rest and calm down 15 minutes before donating blood.

5. You should not donate blood for laboratory research immediately after physiotherapeutic procedures, instrumental examination, X-ray and ultrasound research, massage and other medical procedures.

6. When monitoring laboratory parameters over time, it is recommended to conduct repeated tests under the same conditions - in the same laboratory, donate blood at the same time of day, etc.

7. Blood for research must be donated before starting to take medications or no earlier than 10–14 days after they are discontinued. To assess the control of the effectiveness of treatment with any drugs, a study should be conducted 7-14 days after the last dose of the drug.

If you are taking medications, be sure to notify your doctor.


Indications for the purpose of the study

Women:
1. Early diagnosis of pregnancy;
2. Dynamic monitoring of the course of pregnancy;
3. Suspicion of ectopic pregnancy;
4. Suspicion of a threatened miscarriage and an undeveloped pregnancy;
5. Amenorrhea;
6. Assessment of the completeness of surgical termination of pregnancy;
7. Diagnosis and control of treatment of trophoblastic diseases;
8. Prenatal screening(part of the triple test along with AFP and free estriol);

Men:
1. Differential diagnosis of testicular tumors.

Preparing for the study

In the morning on an empty stomach, after 8-10 hours of fasting (you can drink non-carbonated water), it is acceptable in the afternoon 5-6 hours after a light meal.
On the eve of the study, it is necessary to exclude increased psycho-emotional and intense physical activity, and an hour before the study - smoking.

With this study they pass

  • 8.1. Alpha fetoprotein (liver)
  • 26.76. Antiphospholipid antibodies (ABs to cardiolipids IgM and IgG, annexin V (A5) IgM and IgG, beta-2-glycoprotein IgA, IgM, IgG, PS-prothrombin complex (PS-PT) IgM and IgG)

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;
  • woman uses a complex of medications medicines containing human chorionic gonadotropin;
  • recently had surgery performed artificial interruption pregnancy.

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 in the body begins 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:

  1. 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.
  2. Stimulates the production of sex hormones such as estrogens and androgens.
  3. 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. Largest quantity during pregnancy it 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, it is necessary as much as possible short terms seek help from a doctor 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 resulting from 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, a threat arises spontaneous interruption pregnancy. 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.

When 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.