Modern methods of laboratory diagnostics are impressive in their accuracy and reliability of the results. They can determine even the smallest concentrations of almost all substances and compounds important for the body. In clinical practice, the study of the hormonal spectrum of plasma, including blood for hCG, is widely used. The value of this indicator and its correct assessment is a question of interest to many, and therefore deserves a correct understanding on the part of doctors and their patients.
The value of the hormone and the essence of the analysis
Decoding the abbreviation hCG sounds like human chorionic gonadotropin. This protein compound is a specific hormone that is normally produced only by embryonic tissues. In the synthesis of hCG in early pregnancy, the key role belongs to the chorion (the shell of the embryo, which provides its nutrition), and after 12-14 weeks the placenta, into which the chorion turns. The hormone produced by them constantly circulates in the blood, changing its concentration depending on the gestational age.
As for the chemical structure of this hormone, it is represented by two complex chains of amino acids. The first chain - alpha, is practically identical with the molecular structure of the pituitary hormones, which regulate the synthesis of female sex hormones, menstrual and ovulatory cycles (FSH, LH, TSH). The second chain, beta, refers to that specific set of amino acids that distinguishes hCG from other hormones.
Embryonic tissues and placenta are the main sources of hCG synthesis in the body
The value of chorionic gonadotropin in the body is simply colossal, but only during pregnancy. Thanks to him, all hormonal processes in a pregnant female body are regulated. After all, he actually turns out to be devoid of control from the pituitary gland. All of its hormones are replaced by a single hCG, which stimulates the corpus luteum to produce progesterone, maintains pregnancy and ensures a constant level of estrogen, despite the impossibility of ovulation and the growth of follicles in the ovaries during pregnancy!
Important to remember! Performing a blood test to determine the concentration of the main hormone of pregnancy involves the study of its beta subunit. Therefore, the correct and full name of the diagnostic test should sound like a blood test for human beta-chorionic gonadotropin!
When there are indications for analysis
Any research has clear indications, which are determined by its appropriateness and information content in each specific case. With regard to chorionic gonadotropin, it is advisable to donate blood in such cases:
- Long delay in menstruation (amenorrhea of \u200b\u200bany origin);
- Determination of pregnancy of any period, starting from 5-6 days after fertilization;
- Diagnostics of pregnancy pathology (ectopic, frozen, undeveloped and multiple pregnancies, threat of termination and miscarriage);
- If there is a suspicion of a defective medical abortion;
- Screening monitoring of the course of pregnancy (to take routine tests for all pregnant women without exception in the period from 12-14 to 17-18 weeks);
- Diagnosis of fetal malformations. The diagnostic value of hCG in this regard shows even better performance in combination with blood tests for alpha-fetoprotein (AFP) and estriol;
- Suspicions of malignant neoplasms from embryonic tissues (chorionepithelioma, cystic drift), digestive system, ovaries and testicles.
Research technique and preparation
Determination of the concentration of beta-chorionic gonadotropin belongs to a group of rather complex analyzes. The correctness of further actions of specialists depends on its results. The more subtle the method is, the more factors can influence the research results. Therefore, when performing this study, every little thing must be taken into account at all stages of the analysis: preparation, blood donation and laboratory testing.
Training. Assumes the study is carried out exclusively in the morning. Previous food intake should be no earlier than 6-8 hours before blood sampling (on an empty stomach). Drinking alcoholic beverages and smoking are also strictly excluded. Any stressful situations, nervous and physical overstrain can also affect the results of the analysis, as a result of which a clear norm will be perceived as one or another pathology.
Blood sampling technique. For beta-hCG research, blood plasma is needed. It is obtained by sampling from one of the peripheral veins. The blood is immediately centrifuged to separate the blood cells from the plasma. All other stages of laboratory testing are carried out using special diagnostic reagents.
Important to remember! You can take a blood test for beta-hCG to confirm pregnancy from the 6th day after conception, as it is informative from that time on!
Standards and evaluation of the results obtained
The rate of indicators of chorionic gonadotropin depends on the duration of pregnancy. Cases of detection of this hormone in the blood of women outside pregnancy, and even more so in men, exceeding 5 mU / ml, in no case can be considered as normal. The limits of physiological parameters of beta-chorionic gonadotropin are shown in the table.
| Pregnancy week | Indicator rate in honey / ml | Pregnancy week | Indicator rate in honey / ml |
| 1-2 | 25 - 300 | 7-8 | 20000 - 200000 |
| 2-3 | 1500 - 5000 | 8-9 | 20000 - 100000 |
| 3-4 | 10000 - 30000 | 9-10 | 20000 - 95000 |
| 4-5 | 20000 - 100000 | 11-12 | 20000 - 90000 |
| 5-6 | 50000 - 200000 | 13-14 | 15000 - 60000 |
| 6-7 | 50000 - 200000 | 15-25 | 10000 - 35000 |
| 26-37 | 10000 - 60000 |
The normal course of pregnancy is characterized by a gradual increase in the concentration of hCG. During the first trimester, this process occurs at the fastest pace in the form of doubling the concentration of the hormone every 2-3 days. The peak of beta-hCG activity corresponds to the period of placenta formation (10-12 weeks) and is held for another 1-2 weeks, after which its level gradually decreases to relatively stable numbers, maintained until the very birth.
The exclusion of the pathology of pregnancy and fetus is the main purpose of the blood test for hCG
The main reasons for the increase in the indicator
If, according to the results of the analysis, an increased level of hCG in the blood is recorded, this may indicate:
For pregnant women:
- Pregnancies with the presence of two or more fetuses in the uterus (the dependence of the increase in the analysis index is directly proportional to the number of embryos);
- Gestosis of varying severity;
- The onset of diabetes mellitus in a pregnant woman;
- Genetic diseases and impaired intrauterine development of the fetus (hypoxia, defects, Down syndrome);
- Incorrectly established gestational age according to ultrasound and menstruation;
- Taking hormonal drugs (gestagenic series).
For conditions not related to pregnancy:
- The onset of tumor lesions of the testicles, ovaries, uterus, digestive tract and other organs;
- Tumors from embryonic tissue: choriocarcinoma, chorioepithelioma, cystic drift and its recurrence;
- Taking medications containing the hCG hormone;
- Early after performing a medical abortion or at any time after it if there are suspicions about its usefulness.
What does the decrease in the indicator say?
If the rate of beta-hCG has not been reached according to the results of a blood test, the cause of this condition may be:
- Frozen and undeveloped pregnancy;
- Ectopic pregnancy of any location;
- Delayed intrauterine development of the embryo and fetus;
- The presence of a threat of premature birth or miscarriage;
- Fetoplacental insufficiency and premature aging of the placenta;
- Post-term pregnancy;
- Intrauterine fetal death in late pregnancy.
Important to remember! Only a specialist can evaluate the analyzes. In cases where the results obtained and the norm do not coincide, it is imperative to repeat the studies in 2-3 days!
Alternative diagnostic methods
On the principle of determining the concentration of chorionic gonadotropin in the body, express diagnostics of pregnancy using a pregnancy test is built. The only difference is that there is no need to donate blood, since urine acts as a diagnostic reagent. Any modern test is highly sensitive and informative from the first day of missed periods. Its diagnostic value is much lower than that of a laboratory blood test. These methods have completely different goals and should complement each other, not replace. Moreover, the cost of research varies significantly.
The tactics of combining methods should be as follows: when you just need to confirm the presence of pregnancy, the diagnosis should begin with the use of a conventional test. It is necessary to donate blood only if the test is positive (+) and there are signs of a violation of the course of pregnancy, as well as any suspicions of an ectopic pregnancy. It is possible, but not advisable, to start diagnosing pregnancy with a blood test.
A blood test for beta-hCG is one of the reliable markers for assessing the course of pregnancy to determine threats from the mother and her baby.
HCG (human chorionic gonadotropin) is a specific hormone of the gonadotropic series, which is the main indicator of pregnancy. Normally, it is absent in the human body, and its presence in the blood speaks only of two things:
- pregnancy has come;
- there is a threat of the development of cancer, since some types of cancer cells are capable of producing hCG.
For the most part, hCG is of interest to women precisely to determine the onset of pregnancy, therefore this issue will be considered in detail.
When to donate blood for hCG?
It is important to know that a pregnancy test is nothing more than the same test for hCG, only at home. Due to a sensitive reagent to hCG, which, when interacting with a woman's urine, reacts to the presence of gonadotropic hormone, it is possible to identify whether conception occurred in the early stages, even before the delay of menstruation... These pregnancy tests have different sensitivities. With the most sensitive tests, pregnancy can be determined even before the delay in menstrual bleeding (sensitivity up to 10 mmol / ml), and the most common test strips have a sensitivity of up to 25 mmol / ml.
If you believe the unspoken statistics, then often tests for hCG for home conditions show false positive or false negative results. A false negative is more common than a false positive. Although the manufacturer claims that the probability of error does not exceed 1%, nevertheless, the erroneous indicators exceed the manufacturer's stated percentage. Therefore, relying on the fact that a rapid test at home will show a reliable result is not entirely reliable.
The most optimal analysis to determine the level of hCG in the body will be blood sampling. It is best to donate blood for analysis in the morning on an empty stomach, like all other types of tests. The optimal date is at least 4-5 days after the start of the delay. The fact is that the level of hCG begins to increase only from the moment of implantation of the ovum into the uterine cavity, but not after the last intercourse, or from the moment of the end of ovulation. Before a fertilized egg attaches, it will take at least a week, or even a week and a half, since its path through the fallopian tubes takes a long time. Since most often women become pregnant in the middle of the cycle, when ovulation occurs, then implantation appears approximately before the onset of menstruation in the final phase of the menstrual cycle. From the moment of attachment of the ovum to the uterine cavity, the level of gonadotropin begins to increase daily by 2 times from the previous indicator. This means that if the indicator was 3 mmol / milliliter, then the next day it will be 6 mmol, on the third 12, etc.
Scores from 0 to 5 show the norm for a non-pregnant woman. From 5 to 25 is a controversial indicator that requires re-testing at least in a few days. The hCG test can show the presence or absence of pregnancy when it is carried out on the 3-5th day of delayed menstrual flow. An earlier analysis will not provide accurate information.
Why do you need to be tested for gonadotropin?
Many women do not know why they are tested for this hormone after they find out that they are already in an interesting position. After all, most citizens believe that this analysis is done only in order to confirm or deny the fact of the presence of conception. This is fundamentally wrong. Thanks to these indicators, you can not only identify the fact of conception, but also:
- identify some diseases;
- follow the normal course of pregnancy;
- identify a latent threat to the fetus or the health of the expectant mother.
Inflated or insufficient indicators within a certain period of time after the delay will tell a lot.
Before donating blood for analysis after conception, you need to make sure that the term for an interesting position is set correctly, otherwise you can make a mistake, and this is extremely undesirable, because a medical error costs a lot.
Elevated gonadotropin levels
An increased level of chorionic gonadotropic hormone without deviations from the norm often indicates a multiple pregnancy. In other cases, the value increases:
- with manifestations of severe toxicosis;
- if you suspect the development of fetal pathology (for example, Down syndrome);
- when the child is overmatched;
- in the presence of diabetes mellitus in a pregnant woman;
- with hormone therapy to support the vital functions of the fetus;
- may be increased some time after the abortion;
The worst consequence for the expectant mother, which is indicated by high gonadotropin, is the risk of gestosis or eclampsia. Gestosis is a complicated form of toxicosis in the later stages, which is characterized by:
- severe swelling;
- impaired renal function;
- sharp weight gain;
- increased blood pressure.
If you do not start to treat gestosis in time, then in dynamics it will cause eclampsia, which is characterized by a convulsive seizure. If a woman is not treated in time, she or her child will die. This is why it is so important to do a gonadotropin test during gestation.
Decreased gonadotropine levels
A lowered level of human chorionic gonadotropin may indicate in the early stages after a delay of an ectopic fetal attachment. If the ovum is not located where it is needed, then in any case, an abortion will be performed, otherwise the woman risks dying in the future from a ruptured ovary or fallopian tube. A low level also indicates:
- about the threat of miscarriage;
- about placental insufficiency of the fetus;
- lag in the norms of intrauterine development;
- lack of intrauterine development;
- possible death of the child;
- overriding the fetus at a later date.
In any case, if the result obtained does not fit into the norms in terms of time, an ultrasound examination is urgently needed to finally clarify the existing situation. Also, if a diagnosis is made about the threat of miscarriage, you need to urgently go to the hospital for conservation. In no case should you ignore all the medical recommendations given by the gynecologist regarding treatment or further diagnosis.
How to take a chorionic hormone test correctly
To get the most accurate result, you need to perform a few simple manipulations.
- do not eat before donating blood for 4-6 hours;
- it is best to take blood samples in the morning;
- the day before testing, you must exclude any physical activity;
- before donating blood, you must not drink alcoholic beverages and smoke cigarettes;
- if hormonal drugs are taken as prescribed by a gynecologist, this must be reported to the laboratory assistant.
After receiving the result for hormonal diagnosis of the norm of chorionic hormone, it is necessary to provide the attending gynecologist with all the data obtained for further medical opinion. It is highly discouraged to draw any conclusions and self-medication on your own.
Gonadotropin is a hormone synthesized into the woman's blood by the cells of the membrane 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 5-7th day of the delay in the expected menstruation to obtain a reliable result.
Preparing to donate blood for research
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 should not eat food, juices, coffee, tea and other liquids. It is permissible to drink a glass of plain water. If on the day of the test it was necessary to eat, you should refuse to take blood and postpone the study to another day. It is worth reducing the amount of physical activity, excluding emotional overexcitation. Immediately before donating blood, it is advisable to sit, rest, 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 must refrain from eating for 4-5 hours, after which a study is permissible.Donating blood for hCG
You can donate blood to determine the concentration of hCG on your own for a fee in any medical institution licensed to carry out this type of activity, or in the direction of a gynecologist. Blood sampling is performed in the morning on an empty stomach from a medical vein in the treatment room of a medical and prophylactic institution or antenatal clinic with subsequent transfer to an immunological laboratory for testing for human chorionic gonadotropin.False research results
You should be aware of the existence of false positive and false negative blood test results for hCG. High levels of the hormone in the absence of pregnancy can be detected as a result of a test reaction with substances circulating in a woman's blood, similar to gonadotropin. Taking medications 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 test after a few days or weeks.During pregnancy, a woman's body changes, there are shifts in the hormonal background and the content of certain substances. So, from the first days of conception, the level of human chorionic gonadotropin - hCG sharply increases. Analysis of the amount of this hormone allows you to determine pregnancy with high accuracy. Also, in the woman's body, the PAPP protein begins to be produced in large quantities, the concentration of which helps to identify abnormalities in the development of the fetus.
PAPP analysis
PAPP is a special protein, a high molecular weight glycoprotein, which is found in small amounts in all and. During the time, its content in the blood rises and throughout the entire period of bearing the child is constantly growing. This protein is essential for the proper development of the fetus: it breaks down other proteins, increasing the availability of growth factors and participating in the formation of the immunity of the pregnant woman.
The analysis for PAPP is of great importance: the concentration of protein in the serum of the expectant mother allows conclusions about the development of the fetus. Abnormalities can reveal chromosomal abnormalities: for example, a small amount of protein can indicate possible Down, Corneli de Lange or Edwards syndromes. The analysis is carried out early when other studies do not allow for accurate conclusions. PAPP study with high precision many genetic abnormalities. In addition, they are useful in identifying the threat of miscarriage and stopping pregnancy. You need to take the analysis up to 14 weeks.
The analysis results are ambiguous and do not give a 100% guarantee of the presence or absence of anomalies, but they are sufficiently accurate and provide a basis for further research.
HCG analysis
As a rule, tests for PAPP are performed in conjunction with a general analysis for hCG or human chorionic gonadotropin, a hormone that is produced in a woman's body from the beginning of pregnancy. Already a week after conception, the amount of this substance increases several times, this is enough for an accurate diagnosis of pregnancy.
One-off pregnancy tests give results depending on the amount of hCG in the urine. But a laboratory test that examines blood is much more accurate.
HCG is necessary for the production of hormones estrogen and progesterone, which are involved in the development of the fetus and the formation of the necessary conditions for the growth of the child. HCG maintains the corpus luteum until the fetus can regulate hormones on its own.
With the help of an analysis for hCG, it is possible not only to determine pregnancy in the early stages, but also to obtain data on possible violations, for example, the threat of termination or ectopic pregnancy. Low levels of the hormone can be observed with multiple pregnancies, diabetes mellitus and some pathologies. A very small amount may indicate a delay in fetal development, placental insufficiency, or ectopic pregnancy.
With the help of an analysis for the content of chorionic gonadotropin in biological fluids, it is possible to establish the presence of pregnancy, as well as the nature of its course. It makes sense to donate blood for analysis or do a home rapid test only up to a certain date.
Changes in the concentration of chorionic gonadotropin in biological fluids
After the embryo is implanted into the uterine wall, its active development begins. At the same time, the body is rebuilt, the hormonal background changes. One of the signs of pregnancy is an increase in the concentration of chorionic gonadotropin in the urine and blood. Before its onset, hCG in biological fluids is contained in minimal amounts.
After implantation of the embryo into the wall of the uterus, during each subsequent week, the concentration of hCG in the blood and urine increases exponentially. In order to establish the presence of pregnancy, you can donate blood for the presence of a specific hormone already 4-6 days after conception.
A home rapid test for determining hCG in urine has a much lower sensitivity to gonadotropin. It can be carried out only from the first days of delayed menstruation, but not earlier. Only in this case can you expect to get a reliable result.
A blood test for hCG is the most accurate method for diagnosing pregnancy and the nature of its course. There are certain tables in which all the values \u200b\u200bof the concentration of hCG are prescribed, which are characteristic for a particular period. If the indicators obtained as a result of the analysis differ significantly from the norm, this may indicate the presence of certain violations.
How long can you donate blood for hCG?
Women at risk are forced to periodically donate blood for hCG. This is necessary in order to track the dynamics of an increase or decrease in the concentration of the hormone in biological fluids. Deviations of indicators from the norm can be associated with serious pathologies.
An insufficient increase in the concentration of chorionic gonadotropin in the blood in the early stages of pregnancy may indicate the existing threat of spontaneous termination. Cessation of growth or even a decrease in the concentration of hCG in the blood may indicate the death of the fetus.
It makes sense to do an analysis for hCG only before the 7th pregnancy. After this period, the level of the hormone begins to gradually decrease. At the same time, the rate of its decrease may differ somewhat in individual cases.
For a period of more than 7-9 weeks, there is no need to donate blood for hCG also because during this period, pregnancy is already, as a rule, established, and its development can be monitored by the results of ultrasound studies, which is more informative.
Blood for hCG is subsequently donated once only at 12-14 weeks of pregnancy. In this case, an ultrasound scan is additionally prescribed, since the necessary data on the development of the fetus can be obtained only by simultaneously carrying out both types of diagnostics and comparing their results.
The fastest and most effective way to determine pregnancy is to draw blood to determine the level of hCG. But what is the price of such a test? And how to decipher the results obtained? The answers to these and other questions can be found in our material.
The fastest way to establish pregnancy is with test strips, which can be purchased at every pharmacy. Such a urine test is based on the detection of human chorionic gonadotropin - hCG. But such test strips confirm pregnancy only 14-18 days after fertilization.
Also, the doctor gives a referral for such an analysis in the following cases:
- Revealing the features of fetal development.
- Determining the correct term.
- Elimination of a frozen (or ectopic) pregnancy.
- Determination of the risk of miscarriage.
The accuracy of this test is 98-99%. But there is one drawback - the high cost of analysis.
Important! If you suspect the development of a hormone-producing tumor, men can take an analysis for the concentration of hCG.
When does pregnancy show?
Some doctors advise donating blood 7-10 days after conception, since at the beginning of the term the concentration of such a hormone doubles once every 3 days.
Other experts argue that the analysis should be taken 2 weeks after conception, since according to statistics, only 5% of women have an increased hCG value on the 8th day of the term, and in most pregnant women, the hCG value increases only from day 15.
If a woman cannot remember the specific date of conception, then the test must be taken 30-35 days (4 weeks) after the first day of the last menstruation.
To confirm pregnancy, a second blood sample must be taken (after 3 days) in order to exclude an incorrect reaction of the body. So, during pregnancy, hCG doubles in comparison with the first blood sampling. In the absence of conception, hCG indicators will be reduced or remain unchanged.
Important! If you suspect a frozen (or ectopic) pregnancy, the doctor prescribes a triple test, when blood must be donated three times (with an interval of 2 days).
HCG cost
The price for the hCG test will differ in municipal and private laboratories. So, in commercial clinics, the cost varies between 400-800 rubles. At the same time, the service of such a company will be better than in a municipal hospital.
In a state institution, this analysis will be free, but the disadvantages are the queue and the long term for preparing the test results.
In addition, the cost depends on where the patient lives. So, the average price in Moscow and St. Petersburg will be 700-1000 rubles, and in other cities - up to 600 rubles. 
How to take?
To obtain reliable information, a woman should carefully prepare for such an analysis as follows:
- Analysis time - morning hours on an empty stomach (last meal - 9 hours before blood sampling).
- Physical and emotional stress should be excluded 3-4 days before the analysis.
- You must stop taking medications at least 5 days before blood sampling.
- Do not smoke before analysis (3 hours in advance).
- 2 days before blood sampling, you must not eat fatty, spicy, smoked foods, as well as alcohol.
- After waking up (on the day of the test), you must not drink tea, coffee and other drinks, except for ordinary water.
- You should calm down and sit quietly 20 minutes before blood sampling.
The procedure for taking blood will be as follows: in the treatment room, the patient takes a sitting or lying position (in case of dizziness). The health care provider then puts a tourniquet on the forearm and checks the vein. The next step is to puncture the vein to obtain a sample. After that, the arm should be bent for a few seconds.
After receiving the results, the woman should visit the gynecologist to decipher the hCG data. At the same time, secondary blood sampling should be performed in the same clinic so that the results are not distorted when using different equipment.
HCG decoding
The normal hCG level in non-pregnant women is 0-6 mU / ml. The optimal value of this hormone among men is 2-3 mU / ml.
During the period of childbearing, the hCG rate will increase every 2 weeks. But at the beginning of the term, the concentration of hCG doubles every 3 days. The maximum indicators should be observed at 12 weeks of the term.
The normal level of hCG should be examined in detail in the following table:
In accordance with the indicated table, for each week there are limits for the normal value of hCG. If you deviate from these norms, all kinds of problems may develop. So, with a significant decrease in hCG, such pathologies are formed as:
- Frozen fruit.
- Pregnancy outside the uterus.
- Placental insufficiency - leads to a delay in the development of the child.
- Risk of miscarriage.
- Edwards syndrome is a genetic disorder that causes disability or death of a child.
A significant increase in hCG indicators (more than 2 times) may be associated with:
- Multiple pregnancies.
- Early or late toxicosis.
- The development of Down syndrome.
- Diabetes mellitus.
- Postoperative period (abortion).
- Incorrect pregnancy.
- The presence of congenital pathologies.
- Taking medications, for example, synthetic progestogens (a medicine needed to replenish the female hormone progesterone).
Important! An increase in hCG among non-pregnant women and men often indicates the development of cancer.
When can I collect my results?
The period for obtaining results depends largely on the place where the blood is drawn. So, the average period is 2 days.
When the laboratory independently checks the blood for hCG, then the result can be obtained on the day of blood sampling, since the period for detecting the hormone takes about 3 hours (called the express method). If the laboratory sends the collected material for research to another laboratory, then the result will be ready in about 3-4 days.
More information about blood tests for hCG can be found in the following video:
There is another variant of the development of events - the laboratory independently performs a blood test, but the result will be ready in at least 8-15 days. The main reason is that the laboratory saves money, so the check takes place 1 time in 3 weeks after collecting more than 50-70 blood samples (until the day of testing, the samples are frozen in the freezer).
In conclusion, it is worth noting that the hCG test is suitable for impatient women who want to know about a possible pregnancy 8 days after a potential conception. At the same time, before taking blood, it is worth observing a number of rules, which are discussed in more detail in our article.
HCG (human chorionic gonadotropin) is a special hormone, on the determination of which the establishment of pregnancy is based on the earliest stages. For the normal course of the process, it is very important that the level of this hormone is normal, therefore it is necessary to monitor its indicators throughout the entire period of bearing a child. But how to correctly pass the analysis for hCG so that the results are reliable? Let's figure it out now.
What is HCG
The hCG hormone begins to be produced by the chorionic cells (the shell of the embryo) and continues to be synthesized throughout pregnancy.
The hormone consists of 2 subunits - alpha and beta. The first subunit of hCG has a structure similar to the subunits of such pituitary hormones as FSH, TSH and LH; the second, beta-hCG, has a unique structure. Therefore, to diagnose pregnancy, a laboratory analysis of beta-hCG (β-hCG) is performed.
A blood test for β-hCG allows you to determine pregnancy early enough - already 6-10 days after conception. The level of beta-hCG in the 1st trimester increases almost 2 times every 2-3 days. It reaches its maximum at 8-11 weeks of gestation, after which the amount of hCG begins to decrease and remains at a certain level throughout the remaining period.
Why do you need hCG
The hCG hormone supports the optimal activity of the corpus luteum, in particular, provides the production of progesterone and estrogens, which are necessary for the normal course of pregnancy.
In a male fetus, the hCG hormone stimulates the production of Leydig cells, which synthesize testosterone, which is necessary for the formation of the male reproductive system.
How to get tested for hCG during pregnancy
In order for the results of the analysis for hCG to be reliable, you should adhere to a few simple rules:
- For early diagnosis of pregnancy, the analysis is best done 3-5 days after a delay in menstruation or 12-14 days after the intended conception. Then you can get the right results;
- It is necessary to come for a blood test in the morning on an empty stomach;
- If the analysis for hCG has to be taken during the day, then 4-6 hours before the procedure, you must stop eating;
- The day before the analysis, you should not worry and play sports;
- If a woman is taking hormonal or other medications, then she must inform the doctor about this.
To clarify the results obtained, the analysis for hCG can be repeated again after 2-3 days.
Why do you need to be tested for hCG during pregnancy
In addition to determining the presence and duration of pregnancy, an analysis for hCG is prescribed for dynamic monitoring of its course. If the amount of hCG is lower or higher than normal, this may indicate health problems in the mother or fetus. So, a low hCG value may indicate:
- Frozen or ectopic pregnancy;
- Placental insufficiency;
- Delay in fetal development;
- Threat of miscarriage (if the amount of hCG is 50% of the norm);
- Fetal death (in the last two trimesters).
If the level of hCG is higher than the established norm, then this may indicate:
- Multiple pregnancy;
- Toxicosis;
- Taking progestogens of synthetic origin;
- Incorrectly established period of pregnancy;
- Diabetes mellitus in the mother;
- The development of pathologies in the fetus (Down syndrome, neural tube defect, etc.).
For non-pregnant women, an increased level of hCG may indicate neoplastic diseases of the gastrointestinal tract or ovaries, or neoplasms in the lungs, kidneys, or uterus. Elevated hCG values \u200b\u200bcan also be detected within 5-6 days after an abortion.
If during pregnancy there is a too rapid increase in the concentration of hCG, then this may indicate a complication such as cystic drift. It is caused by abnormal development of the chorionic villi, which feed the embryo before the placenta forms. As a result of this, the chorion ceases to perform its functions, and, as a result, the pregnancy freezes.