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 definition Pregnant 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. For this reason, the patient needs to without fail pass additional complex 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 future 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.
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. because of individual characteristics woman's body, or errors in work medical personnel sometimes you have to go through 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 specified norms for a certain period pregnancy, this may indicate 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.
Human chorionic gonadotropin is a protein hormone produced by the chorion after implantation of the fetal egg in the endometrium of the uterus. observed from the moment of conception and reaches a peak by 10-11 weeks of pregnancy.
An increase in the level of gonadotropin in men and women who are not in position indicates the formation of a hormone-producing trophoblastic tumor. An analysis for hCG is prescribed to determine the exact gestational age, diagnose the condition of the fetus, and confirm oncological diseases.
Functions of chorionic gonadotropin
As early as 7–8 days after fertilization of the egg, the tissues of the developing embryo prevent the detachment of the endometrium of the uterus and the onset of menstruation. Its main function is to prevent the involution of the corpus luteum, which produces progesterone and estrogens, which ensure implantation and normal gestation.
Under the influence of hCG, the corpus luteum constantly grows and persists until the 13-17th week of pregnancy. After that, the placenta begins to produce hormones, and the temporary gland undergoes reverse development. Chorionic gonadotropin stimulates the synthesis of testosterone in the testes of the male fetus. Androgen production is maintained until delivery.
The protein hormone suppresses immune responses in a woman's body, so that the rejection of the embryo does not occur, which is especially important in the early stages of pregnancy. After 6 weeks, the placenta is formed, which protects the fetus from immunocytes.
Up to 8–9 weeks, hCG supports the growth and development of chorionic villi in the uterine epithelium, through which the child receives nutrients and oxygen from the mother, and metabolic products are utilized. Another function of the glycoprotein is to stimulate the production of glucocorticoids, which is necessary for the body to adapt to constant immune stress.
Types of analysis
Chorionic gonadotropin consists of α and β subunits; in the blood, the hormone is predominantly in a complex structure and is defined as general. Free hCG circulates in less quantity, but its concentration has a more important diagnostic value. Beta subunits make it possible to detect intrauterine fetal pathologies, hydatidiform mole, the formation of trophoblastic tumors, and perform monitoring after IVF.
Indications for analysis for total hCG:
- early diagnosis of pregnancy;
- in the complex of perinatal screening in the 2nd trimester.
A study on free b hCG is prescribed for screening of the 1st trimester, for the diagnosis of choriocarcinoma, hydatidiform mole. The indication for diagnostics is the age of a woman over 35 years old, a history of chromosomal diseases. A blood test reveals the Down, Paul, Edwards, Kleifenthalm syndrome in the unborn child.
Chorionic gonadotropin is also found in the urine, but in lower concentrations. In urine, the increase in hCG levels occurs more slowly than in the blood, therefore, to determine pregnancy in the early stages, it is prescribed laboratory research serum.
Normal performance
The results of hCG in the stronger sex and non-pregnant women do not exceed 5 mU / ml. After fertilization of the egg, the production of chorionic gonadotropin begins to gradually increase, thanks to which the attending physician can reliably determine the time of conception.
How to decipher the result of a blood test for hCG during pregnancy? A table of hormone levels growth by week will help evaluate the responses of laboratory tests:
| Pregnancy period, weeks | Normal indicators b hCG, honey / ml |
| 1–2 | 25–150 |
| 2–3 | 100–4875 |
| 3–4 | 1100–31500 |
| 4–5 | 2550–82000 |
| 5–6 | 23000–150000 |
| 6–7 | 27400–233500 |
| 7–11 | 20100–290000 |
| 11–17 | 6150–104000 |
| 17–22 | 4730–80200 |
| 22–39 | 2600–78000 |
To accurately determine the diagnosis and timing of pregnancy, it may be necessary to repeat the analysis. It should be borne in mind that the limit values \u200b\u200bcan differ significantly when diagnosing in different laboratories, so the correct interpretation of the results should be performed by the attending physician.
False-negative answers can be obtained when taking hormonal drugs. The study is carried out no earlier than 4-5 after the delay of menstruation, a second test is done after 2-3 days.
In women over 40, hormonal changes occur in the body, reproductive function fades, and menopause occurs. At this time, the level of hCG in the blood rises and has indicators identical to the early stages of pregnancy. In such cases, an additional examination by a gynecologist, ultrasound, laparoscopy is required.
Elevated hCG levels
If the level of human chorionic gonadotropin in the blood in non-pregnant women and men exceeds the permissible values, this may be a sign of a serious illness. High levels of hCG are diagnosed with the following pathologies:
- cystic drift - an anomaly in the development of the embryo;
- artificial insemination;
- cancer of the kidneys, uterus, lungs;
- diabetes;
- chorioncarcinoma;
- tumors of the testicles, organs of the gastrointestinal tract.
In addition to these diseases, a high one is fixed in the first 4-5 days after a medical abortion, the hormonal background normalizes after 8-14 days. In some cases, after curettage of the uterus, elements of the embryo remain, which continue to synthesize chorionic gonadotropin. This is the reason for a thorough examination of the woman and a second operation.
High level HCG during pregnancy can be a symptom of multiple pregnancies, early toxicosis, preeclampsia, genetic abnormalities in the development of the fetus, and the child's overbearing beyond the due date. It helps to increase the hormone by taking synthetic progestogens, which are prescribed to women to correct progesterone levels. With multiple pregnancies, the production of b hCG increases by 2 or more times, depending on the number of embryos.
Low hCG
In pregnant women, it may be a sign of such pathologies:
- risk of miscarriage;
- ectopic pregnancy;
- placental insufficiency;
- true overgrowth;
- anomalies in the development of the embryo;
- undeveloped pregnancy.
A decrease in the concentration of hCG by more than 50% indicates the death of the fetus in the 2nd or 3rd trimester or indicates serious abnormalities in the development of the embryo. In the early stages, such indicators occur with the threat of spontaneous abortion.
Fetal anomalies
In addition to testing for hCG, pregnant women undergo neonatal screening for the timely detection of possible abnormalities in the development of the child. The examination complex includes the determination of total and b hCG, estriol-A, PAPP-A, ACE, ultrasound.
The following pathologies can lead to a change in the level of chorionic gonadotropin in the blood of a pregnant woman:
- Down syndrome is characterized by an increase in total hCG by 2 or more times, a low level of PAPP-A, and an increase in the thickness of the collar space. Ultrasound examination determines the physical pathologies of fetal development.
- Edwards and Patau syndrome is confirmed with an insufficient level of hCG β-subunits and other markers. About half of newborns with this diagnosis die in the first months of life, the rest do not live up to 1 year.
A geneticist should correctly decipher the blood test for hCG in the presence of deviations. To confirm chromosomal abnormalities in the fetus, a woman needs to undergo additional studies using an invasive diagnostic method.
Trophoblastic tumors
If hCG decoding indicates an increased level of human chorionic gonadotropin in the blood serum in men and non-pregnant women, there is a high risk of malignant tumors formed from trophoblasts.
Choriocarcinoma develops against the background of hydatidiform drift, after abortion, childbirth, ectopic pregnancy. In 2-5% of clinical cases, the tumor has no connection with the conception and birth of a child. It is localized in the body of the uterus, where the embryo was previously attached. In rare cases, a neoplasm is detected in:
- ovaries;
- vagina;
- fallopian tubes;
- abdominal cavity;
- lungs;
- bladder;
- brain.
The cause of the development of choriocarcinoma is considered to be: viral damage to trophoblasts, immunosuppressive effects of hCG, progesterone, estrogens, metabolic disorders. At risk are women over 40 years of age with a history of abortions, miscarriages, missed and ectopic pregnancies, cystic mole.
In men, it is synthesized by testicular carcinoma. A high level of this hormone (more than 5 mU / ml or 1 U / l) indicates the presence of malignant cells that produce chorionic gonadotropin. Patients undergo ultrasound, additional examination for tumor markers: AFP (alphafetoprotein), LDH (lactate dehydrogenase).
Deciphering the results of the analysis for hCG is carried out by the attending physician. To accurately determine the diagnosis and eliminate errors, blood must be taken several times. An increase or decrease in the level of human chorionic gonadotropin can be a symptom of a serious illness, pathological course or fading of pregnancy.
HCG - chorionic gonadotropin
The hCG hormone is produced by the cells of the chorion (the membrane of the embryo) after the implantation of the embryo into the uterus. Based on a blood test for b-hCG, the doctor determines the presence of chorionic tissue in the body, which means that the woman is pregnant. An hCG blood test makes it possible to determine pregnancy early - as early as 6–10 days after fertilization, the hCG result will be positive.
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 is very important. In the male fetus, hCG 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, it is of crucial importance in the diagnosis laboratory analysis b-hCG.
You can also diagnose pregnancy with the help of home pregnancy tests based on the analysis of hCG excreted in the urine. But the reliability of the hCG result obtained by the "home" method is significantly lower than the laboratory analysis of hCG blood, since the level of hCG in the urine necessary for diagnosis is reached a few days later than in the blood.
The most common cases when a doctor prescribes an analysis for hCG:
Among women:
Amenorrhea
Diagnosis, determination of pregnancy in the early stages
Rule out the possibility of an ectopic pregnancy
To assess the completeness of induced abortion
HCG is also given for dynamic monitoring of pregnancy
With the threat of miscarriage and non-developing pregnancy
Diagnosis of tumors - chorionepithelioma, hydatidiform mole
Along with AFP and free estriol - as a prenatal diagnosis of fetal malformations
For men:
Diagnosis of testicular tumors.
In the blood serum
The norm of hCG, honey / ml
Men and non-pregnant women< 5
HCG levels during pregnancy:
1 - 2 weeks 25 - 300
2 - 3 weeks 1500 - 5000
3 - 4 week 10000 - 30000
4 - 5 week 20000 - 100000
5 - 6 week 50000 - 200000
6 - 7 week 50000 - 200000
7 - 8 week 20000 - 200000
8 - 9 week 20000 - 100000
9 - 10 week 20000 - 95000
11 - 12 week 20000 - 90000
13 - 14 week 15000 - 60000
15 - 25 week 10000 - 35000
26 - 37 week 10000 - 60000
Note!
Weekly hCG rates are given for the duration of pregnancy "from conception" (and not for the duration of the last menstruation).
The above figures are not a standard! Each laboratory can set its own hCG standards, including Fetal development by week. 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 for hCG!
HCG growth by DPO days (day after ovulation):
No. dpo - min [average] max
7 dpo - 2 10
8 dpo - 3 18
9 dpo - 5 21
10dpo - 8 26
11dpo - 11 45
12dpo - 1765
13dpo - 22,105
14dpo - 29,170
15dpo - 39,270
16dpo - 68,400
17dpo - 120,580
18dpo - 220 840
19dpo - 370 1300
20dpo - 520 2000
21dpo - 750 3100
22dpo - 1050 4900
23dpo - 1400 6200
24dpo - 1830 7800
25dpo - 2400 9800
26dpo - 4200 15600
27dpo - 5400 19500
28dpo - 7100 27300
29dpo - 8800 33000
30dpo - 10500 40000
31dpo - 11500 60000
32dpo - 12800 63000
33dpo - 14000 68000
34dpo - 15500 70000
35dpo - 17000 74000
36dpo - 19000 78000
37dpo - 20500 83000
38dpo - 22000 87000
39dpo - 23000 93000
40dpo - 25000 108000
41dpo - 26500 117000
42dpo - 28000 128000
HCG decoding
Normally, during pregnancy, the level of hCG gradually rises. During the 1st trimester of pregnancy, the level of b-hCG rises rapidly, doubling every 2-3 days. At 10-12 weeks of gestation, the highest level of hCG in the blood is reached, then the level of hCG begins to decrease slowly and remains constant during the second half of pregnancy.
An increase in beta-hCG during pregnancy can occur with:
multiple pregnancy (hCG 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
An increase in hCG can be a sign of serious illness in non-pregnant women and men:
testicular tumors
tumor diseases of the gastrointestinal tract
neoplasms of the lungs, kidneys, uterus
hydatidiform mole, recurrence of hydatidiform mole
chorioncarcinoma
taking hCG medications
an hCG test was done within 4-5 days after the abortion, etc.
Usually, hCG is elevated if the hCG test was performed 4-5 days after the abortion or due to the use of hCG preparations. A high hCG level after a mini-abortion indicates an ongoing pregnancy.
Low hCG in pregnant women may mean an incorrect definition 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 (lowered hCG by more than 50%)
chronic placental insufficiency
true miscarriage
fetal death (in the II-III trimester of pregnancy).
It happens that the results of the analysis of hCG show the absence of the hormone in the blood. This result can be if the hCG test was performed too early or during an ectopic pregnancy.
Whatever the result of the analysis for hormones during pregnancy is, remember that only a qualified doctor can give a correct interpretation of hCG, determining which hCG is the norm for you in combination with data obtained by other examination methods.
How to take a blood test for the hCG hormone
To perform an hCG analysis, blood is taken from a vein. It is recommended to take blood for hCG in the morning and strictly on an empty stomach. If you are taking the hCG test at any other time, you must abstain from food for 4-6 hours. And you should tell your nurse or your doctor if you are taking any hormonal medications.
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 hCG, chorionic gonadotropin, is given from 14 to.
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.
