When is the best time to take an hcg test? What does a blood test for hCG show and how to prepare for the study. Normal levels of hCG
Among the list of tests that a woman must undergo during pregnancy or just planning to become a mother, you can find the abbreviation "hCG" but what is it? This analysis shows the amount of human chorionic gonadotropin, let's consider it in more detail.
HCG, what is it?
HCG is a hormone that has a protein nature and consists of two fractions - alpha and beta. Of clinical interest is the beta fraction of the hormone, since alpha is similar in structure to other female hormones. And beta is unique - this makes it easy to determine it in the blood.
The biological role of hCG in the body of a pregnant woman:
1. The hCG hormone contributes to the preservation of the corpus luteum during pregnancy and the production of progesterone by it before the full work of the placenta begins. This contributes to the preservation of pregnancy and the bearing of a healthy child. Without enough hormone, motherhood will not take place. The placenta begins to synthesize female hormones on its own from about 16 weeks.
2. Chorionic gonadotropin helps a woman get used to the onset of pregnancy, stimulating the adrenal glands to produce glucocorticoids, making the expectant mother more resistant to stress. Carrying a child is stressful for the female body, especially in the early stages.
3. When the placenta has already formed (at week 16), hCG provides good nutrition and development, preventing premature detachment.
4. In medicine, the introduction of a hormone through injections is practiced. It stimulates ovulation and promotes conception in women. Using such injections in men, you can achieve an increase in the level of sex hormones and improve the quality of sperm.
Norms of hCG indicators in women
It is not difficult to take an analysis for the level of hCG: this is an ordinary blood test from a vein. The result of the analysis is usually issued on the same day or the next.
Deciphering the result of the analysis done for hCG lies on the shoulders of the doctor. It is difficult to understand the abundance of numbers and meanings on your own. However, you should remember how the hormone level changes depending on the duration of pregnancy and know the average values ββin non-pregnant women (see table).
Important! Norm indicators may vary, depending on the laboratory that performed the analysis.
In girls and men, hCG levels should be 0-5 mU / ml. This amount is so small that a test performed to determine hCG in the urine does not respond to it and will show one strip.
From the first days of pregnancy, the level of hCG will increase. This happens until 11β12 weeks, when the highest value of the hormone is noted. Further, gonadotropin gradually decreases and in the last stages of pregnancy shows approximately the same value.
Increasing hCG during pregnancy
With the onset of fertilization, the level of human chorionic gonadotropin increases. This happens literally immediately after fertilization.
The quantitative composition of the hormone is steadily growing and reaches a maximum by week 11, and then declines. In the second half of pregnancy, the indicators stabilize and change little.
Express tests sold at a pharmacy to determine pregnancy can change color when hCG is found in the urine. Although the method is not as revealing as a blood test for hCG, it is still quite accurate. In a non-pregnant woman, the result will be negative, while a pregnant woman will be able to find out about the presence of pregnancy before other signs appear.
A blood test for chorionic gonadotropin is able to give an answer after 7-10 days from the moment the egg and sperm meet. Obtaining the results of an hCG analysis at such an early date makes it possible to control the course of pregnancy almost from the very moment of fertilization.
Carefully monitoring the levels of the most important pregnancy hormone will help prevent pregnancy complications, including its termination. This is true for women who unsuccessfully tried to experience the joy of motherhood, as well as for late-born or women with a burdened obstetric history.
If the level of hCG in a woman "in an interesting position" exceeds the norm, then this may be evidence of the following processes in the body:
- When carrying two or three fruits.
- Diseases of the fetus at the chromosomal level (Down's syndrome).
- Diabetes mellitus in the anamnesis of a pregnant woman.
- Severe course of gestosis during pregnancy.
- The use of female hormones from the outside.
Decrease in hCG during pregnancy
Gonadotropin levels may decrease in the following cases:
- With an atypical location of the fetal egg (tubal, or).
- If the fetus lags behind in its development.
- With a frozen pregnancy.
- In violation of blood circulation between the baby and the placenta or between the placenta and the uterus.
- If .
- When overridden.
Increasing hCG in women and men
A blood test for the hCG hormone in a non-pregnant woman or in men provides important diagnostic information. There were cases when men, for fun, did an analysis using a pregnancy test and received two strips.
On the one hand, this seems to be ridiculous and impossible, but on the other hand, this is not a reason for jokes. Chorionic gonadotropin can appear in the body of men and women with the development of a malignant tumor.
These are the so-called hormone-producing tumors that can form in the organs of the reproductive system, lungs, and stomach.
Deciphering the analysis of hCG, table
For a doctor, deciphering the result of an hCG analysis carries a lot of information during pregnancy. By analyzing the blood counts for the quantitative content of the hormone, the doctor will determine the gestational age with high accuracy, and will also be able to suspect an ectopic pregnancy, some flow pathologies, an impending miscarriage, etc.
This will help to take measures to save the desired child and take actions aimed at preventing complications in the expectant mother and her baby.
Of course, only the level of this hormone is not diagnosed. More research is needed. But it is the amount of the main mother hormone that indicates a possible problem and directs the doctor in the right direction to identify this problem.
| Gestational age | Mean value, mIU/ml | Limit values, mIU/ml |
| 2 weeks | 150 | 50-300 |
| 3-4 weeks | 2000 | 1500-5000 |
| 4-5 weeks | 20000 | 10000-30000 |
| 5-6 weeks | 50000 | 20000-100000 |
| 6-7 weeks | 100000 | 50000-200000 |
| 7-8 weeks | 80000 | 40000-200000 |
| 8-9 weeks | 70000 | 35000-145000 |
| 9-10 weeks | 65000 | 32500-130000 |
| 10-11 weeks | 60000 | 30000-120000 |
| 11-12 weeks | 55000 | 27500-110000 |
| 13-14 weeks | 50000 | 25000-100000 |
| 15-16 weeks | 40000 | 20000-80000 |
| 17-21 weeks | 30000 | 15000-60000 |
The results of the analysis for hCG made in the laboratory can be indicated in different units of measurement: mU / ml, U / lm, IU / ml, mIU / ml - this is the same thing. remember, that The rate of results in each laboratory may vary slightly!
Human chorionic gonadotropin (hCG)- This is a hormone that is formed after the implantation of the embryo into the uterine cavity and is produced by the chorion (the shell of the embryo). The level of the hCG hormone is very important for the normal development of pregnancy, which is why it is so important to monitor it.
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hCG consists of two subunits - alpha and beta. To determine pregnancy, the analysis is carried out for the content of beta subunits ( beta hCG). The concentration of beta-hCG in the blood of a pregnant woman approximately doubles every 2-3 days. Its peak is reached at the 8-11th week of pregnancy, after which it begins to decline.
Elevated hCG occurs with:
- toxicosis
- multiple pregnancies
- pregnant woman with diabetes
- taking synthetic gestagens
- fetal pathologies (Down syndrome, multiple malformations)
- if the gestational age is set incorrectly
Low hCG occurs when:
- missed pregnancy
- ectopic pregnancy
- fetal growth retardation
- placental insufficiency
- threatened miscarriage (hCG decreased by more than 50%)
- fetal death (in the II-III trimester of pregnancy)
For non-pregnant women and for men, elevated levels of hCG can be a sign of tumor diseases of the gastrointestinal tract; testicular tumors; neoplasms of the lungs, kidneys, uterus; cystic drift; with an abortion (after 4-5 days).
When to take an hCG test?
Take a blood test for hCG it is possible on the 3-5th day of delayed menstruation or on the 12th day after conception, however, the presence of hCG in the blood will be already on the 7th day after conception, however, the accuracy of the analysis will be low and it will still be necessary to pass it control.
In order to trace the dynamics of hCG, it is necessary to donate blood three times with a difference of 2 days, preferably at the same time.
How to take an hCG test?
Blood test for hCG it is given in the morning on an empty stomach, if the analysis is given in the afternoon, then before it you can not eat for 4-6 hours. The day before the test, it is necessary to exclude physical activity. If you are taking hormonal drugs, then this must be reported to the doctor.
Deciphering the analysis of hCG
| Pregnancy by week, starting from the first day of the last menstruation | HCG level (mU / ml) |
| 3 - 4 | 25 - 156 |
| 4 - 5 | 101 - 4870 |
| 5 - 6 | 1110 - 31500 |
| 6 - 7 | 2560 - 82300 |
| 7 - 8 | 23100 - 152000 |
| 8 - 9 | 27300 - 233000 |
| 9 - 13 | 20900 - 291000 |
| 13 - 18 | 6140 - 103000 |
| 18 - 23 | 4720 - 80100 |
| 23 - 31 | 2700 - 78100 |
During pregnancy, a large number of changes occur in the body of women, including hormonal levels. From the first days after fertilization, pregnant women begin to actively produce hCG, the hormone of chorionic gonadotropin. It is recommended to take a blood test for hCG when it is necessary to confirm the fact of conception and in order to prevent the development of adverse consequences for the child.
HCG (chorionic gonadotropin hormone) is a specific hormone produced by the tissues of the embryo. In the early stages of pregnancy, the hormone is synthesized due to the chorion (the outer shell of the embryo that provides nutrition), and after 12 weeks, the placenta. HCG is constantly present in the blood of women, only the concentration of its content changes relative to the gestational age. The structure of hCG consists of two complex chains of amino acids - alpha and beta.
The significance of chorionic gonadotropin for the body is relevant only during the period of bearing a child, but it is very ambiguous. Thanks to him, all hormonal processes are carried out in women who are expecting a baby. HCG is not controlled by the pituitary gland and replaces all the hormones it produces. Chorionic gonadotropin stimulates the synthesis of progesterone and thanks to it the constancy of the estrogen content is ensured.
According to the result of the test for hCG, you can set the exact gestational age. This blood test has earned its respect for many years, due to its accuracy and reliability. In addition, the test allows you to diagnose the correct course of pregnancy. Based on the results of the study, it is possible to draw a conclusion about what possible complications for the fetus. Timely analysis and, as a result, detected violations help to get rid of a large number of adverse consequences.
Indications and preparation for analysis
The expediency of conducting a blood test for hCG, like any other analysis, should be determined by the doctor, based on the indications for each individual patient. The test for chorionic gonadotropin should be taken with the following indications:
- amenorrhea, of various etiologies - the absence of menstruation for several cycles;
- diagnosis of pregnancy, 5 days after fertilization;
- determination of pathological disorders during pregnancy;
- suspicions of a poor-quality abortion;
- planned diagnostics of the course of pregnancy (must be taken by everyone after 12 weeks);
- determination of defects in a developing fetus;
- suspicion of oncological diseases from the tissues of the embryo, digestive tract, ovaries.
The beta-chorionic gonadotropin test is considered a complex test. The correctness of the prescribed treatment and further examination largely depends on the results of the study. Since the analysis is considered complex and accurate, many factors can affect the correctness of the results obtained. When it becomes necessary to donate blood for hCG, it is necessary to take into account all the nuances, which include: preparation, the very process of taking the material and laboratory testing.
When preparing for the test, you need to follow simple rules, which will allow you to get reliable results of the study. Blood must be taken strictly on an empty stomach in the morning, you can drink clean water. A few days before blood sampling, it is required to exclude alcoholic beverages, fatty, fried and spicy foods. Smoking before the study is prohibited. It is not recommended to do physical exercises and expose yourself to stress on this day.
For the test, blood is taken from a vein, the elbow is best suited. Plasma is needed for research, therefore, after taking blood, it is placed in a special centrifuge, where the process of separating cells from plasma takes place. Further study of the material is carried out using reagents. Thanks to modern research methods, the analysis for chorionic gonadotropin shows the most accurate and reliable result.
Normal hCG values
When a woman is fertilized, the level of hCG begins to change. Fluctuations in indicators continue throughout the entire period of pregnancy. From the first days after conception, its rapid growth can be observed. Upon reaching the peak level, the increase in the level of human chorionic gonadotropin is inhibited and remains almost unchanged, followed by a gradual decrease.
In the first weeks of pregnancy, the hCG level doubles within 2-3 days. 6-7 weeks after conception, growth stops and a gradual decrease in its content can be noted.
The expediency of testing for hCG for diagnostic purposes is applicable up to 20 weeks of pregnancy. HCG rates may vary depending on the laboratory. In this regard, it is necessary to do the analysis always in the same laboratory. The average allowable norms of hCG have the following values:
From the table below, you can see how much hCG norms are and how they change depending on the gestational age. It should be noted separately that when chorionic gonadotropin is found at a concentration of more than 5 IU / l in the absence of pregnancy or in men, it can be concluded that there are violations and an urgent need to consult a doctor for examination.
Reasons for the deviation of the level of hCG
When the result of the test for hCG is obtained, you should consult a doctor to decipher and assess the risk of deviation of the values, if any. When an elevated hormone level is determined in pregnant women, the reasons may be the following:
- multiple pregnancy;
- preeclampsia is a complication of a normal pregnancy;
- development of diabetes;
- diseases transmitted at the genetic level and deviations of the intrauterine development of the child;
- incorrectly set gestational age based on the result of ultrasound and menstruation;
- hormonal therapy.
When the test is done in compliance with all the rules of preparation during the absence of pregnancy, and as a result an increased value of the level of chorionic gonadotropin is determined, the reasons for the deviation may be: a tumor of the organs of the reproductive and digestive systems; tumor formations of embryonic tissue; therapy with drugs containing the hCG hormone; consequences of medical termination of pregnancy.
- "frozen" pregnancy;
- development of the fetus outside the uterine cavity;
- pathology of intrauterine development of the fetus;
- risk of spontaneous abortion;
- disorders of the placenta;
- delayed pregnancy;
- late fetal death.
The interpretation of the analyzes should be carried out by a qualified doctor. If there are deviations from the norm, then it is necessary to donate blood again for 2-3 days. If the results obtained are similar, then treatment should be started immediately. With the development of pathologies during pregnancy, every day is important.
Other diagnostic methods
A similar principle for determining the level of chorionic gonadotropin has an express diagnosis of conception using a pregnancy test. The difference is that you do not need to donate blood. The determination of the fact of fertilization during express diagnostics is determined using urine. Modern tests are highly sensitive and highly informative, give a positive result already on the first day of a missed period.
Rapid tests are not as valuable as blood tests. The methods have completely different diagnostic goals and complement each other, but in no way replace. The undoubted advantages of express diagnostics are that you do not need to wait for the results of the study and the test can be performed on any day, there is no need to donate blood.
You can combine these methods as follows: if you want to confirm conception, then it is important to use an express test and the result will be obtained on the same day. With a positive result and suspicion of a violation of the course of pregnancy or other deviations, it is advisable to donate blood for hCG and other examinations. It is not advisable to start the diagnosis of conception with a blood test, of course, it is not prohibited, but it is worth considering that the result will not be obtained on the same day and the amount of costs will be much higher.
A blood test for hCG is highly reliable and allows you to assess the correctness of the course of pregnancy to diagnose complications that threaten the bodies of a woman and a child. A laboratory test allows you to determine the fact of conception in the early stages, but it is still recommended to donate blood 3-5 days after a missed period. If the results of the study have deviations from the norm, then there is no need to worry, the gestational age may have been incorrectly set, for example, by ultrasound. Will need to retake in one day.
Gonadotropin is a hormone synthesized in the blood of a woman by the cells of the shell of the formed embryo. All pregnancy tests and studies are based on determining the concentration of the hormone in the blood. The normal value of hCG is considered to be a concentration of 0-5 mU / ml. The concentration of the hormone rises sharply every 48 hours. In the first or second week of pregnancy, the level of gonadotropin should be in the range of 25-300 mU / ml. It is advisable to take a blood test for chorionic gonadotropin on the 5th-7th day of the expected menstruation delay in order to obtain a reliable result.Preparing to donate blood for testing
The day before the proposed analysis, it is recommended to follow a special diet that excludes fatty foods, fried foods, and alcoholic beverages from the diet. On the day of blood donation, you can not eat food, juices, coffee, tea and other liquids. Let's drink a glass of plain water. If on the day of the test there was a need to eat, you should refuse to take blood and reschedule the study to another day. It is necessary to reduce the amount of physical activity, to exclude emotional overexcitation. Immediately before donating blood, it is advisable to sit, relax, relax for 10-15 minutes. It is not recommended to smoke 1 hour before the study. You should inform the gynecologist about the drugs taken at the time of the blood test for hCG. If it is necessary to urgently determine the concentration of gonadotropin in the blood, you should refrain from eating for 4-5 hours, after which it is permissible to conduct a study.Donating blood for hCG
You can donate blood to determine the concentration of hCG on your own for a fee at any medical institution licensed to carry out this type of activity, or in the direction of a gynecologist. Blood is taken in the morning on an empty stomach from a medical vein in the treatment room of a medical institution or antenatal clinic, followed by transfer to an immunological laboratory for testing for human chorionic gonadotropin.False results of the study
You should be aware of the existence of false positive and false negative results of a blood test for hCG. High levels of the hormone in the absence of pregnancy can be detected as a result of the reaction of the test with substances circulating in the woman's blood, similar to gonadotropin. Taking medicines containing chorionic gonadotropin in the treatment of infertility gives a false positive test result. The reduced content of the hormone during pregnancy does not refute its presence. It is recommended to retake the analysis in a few days or weeks.Human chorionic gonadotropin (hCG) is a hormone that begins to be produced by the placenta as a result of the introduction of a fertilized egg into the uterine cavity. Therefore, normally, the presence of chorionic tissue in the body indicates the onset of pregnancy. But sometimes an increase in the concentration of hCG does not indicate the development of the fetus, but the formation of a tumor neoplasm. The most important function of hCG is to maintain pregnancy. By the level of the hormone, one can judge the nature of the course of pregnancy, the presence of several fetuses. In the first trimester, human chorionic gonadotropin stimulates the production of estrogen and progesterone.
Alpha and beta hCG
Human chorionic gonadotropin is formed by two subunits - beta and alpha. Alpha hCG has a structure similar to follicle stimulating hormone (FSH), thyroid stimulating hormone (TSH), luteinizing hormone (LH). The beta subunit (b-hCG) is unique, therefore it is by its presence in the urine and blood that the onset of pregnancy is determined.
Total and free b-hCG
A blood test to determine total b-hCG is aimed at early diagnosis of pregnancy. It also allows you to monitor the development of the fetus - if there are no deviations, the hormone level first gradually increases, and in the second half of pregnancy it begins to decrease. Thus, if a woman wants to know if she will become a mother in 9 months, she needs to take a blood test for total b-hCG. Free b-hCG (free b hCG subunit) is included in the concept of prenatal screening - a study aimed at identifying the risk of developing malformations in the fetus. Its level is very low, so it is not used to diagnose pregnancy.
Indications for analysis for the concentration of b-hCG
A blood test for total b-hCG is performed for:
- diagnosing pregnancy in the early stages,
- exclusion of ectopic pregnancy,
- evaluation of the effectiveness of the induced abortion,
- detection of tumors,
- assessment of the normal course of pregnancy,
- exclusion of non-developing pregnancy,
- diagnosis of fetal malformations in the first and second trimesters of pregnancy.
For men, a blood test for b-hCG is prescribed if tumor diseases of the testicles and prostate are suspected.
Indications for a blood test for free b-hCG are:
- pregnancy over the age of 35,
- diagnosis of various fetal pathologies in the first trimester of pregnancy (Patau syndrome, Down syndrome, Edwards syndrome),
- radiation exposure of a pregnant woman or father of a child,
- the presence of congenital malformations in relatives of the pregnant woman.
Preparation for the analysis of b-hCG
To determine the level of the hormone b-hCG, blood is taken from a vein after 8-12 hours of fasting (on an empty stomach). If the patient is taking any medications, she must inform the doctor in advance. In order to determine pregnancy, blood should be donated no earlier than on the third day of delay.
For maximum reliability and tracking the dynamics of the level of chorionic gonadotropin, it is desirable to repeat the blood sampling after 2-3 days.
The rate of concentration in the blood of the hormone b-hCG
The norm of the hCG hormone in the blood of non-pregnant women and men is from 0 to 5 mU / ml. In pregnant women, the free b subunit of hCG must comply with the following standards:
| Pregnancy (week) | HCG level (mU / ml) |
| 1-2 | 50-300 |
| 2-3 | 300-1 500 |
| 3-4 | 1 500-5 000 |
| 4-5 | 10 000-30 000 |
| 5-6 | 20 000-100 000 |
| 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 | 10 000-30 000 |
| 26-38 | 10 000-60 000 |
What does an increased level of b-hCG in pregnant women indicate?
A significant increase in the level of the hormone b-hCG may indicate that:
- multiple pregnancy,
- gestational age is set incorrectly,
- a pregnant woman has diabetes,
- early toxicosis is pronounced.
Also, a high level of b-hCG is a sign of Down syndrome (but other markers must be taken into account to make a final diagnosis). In late pregnancy, an overestimated indicator indicates overmaturity.
High levels of b-hCG in men and non-pregnant women
Sometimes an increased concentration of the hormone b-hCG is found in men and non-pregnant women. This result is a consequence of:
- taking medications containing human chorionic gonadotropin,
- the presence of neoplasms in the kidneys, uterus, gastrointestinal tract, testicles and other organs,
- chorioncarcinoma,
- cystic drift.
Also, a high level of the hormone usually persists for one week after an induced abortion.