One of the important diagnostic methods that are carried out during pregnancy is considered to be an analysis for. This study can determine fertilization as early as the fifth to seventh day after conception. In addition, using this analysis, you can set the exact period, because the indicator of this substance varies depending on the week of pregnancy.
From this article, you can also find out what are the reasons for the deviation of hCG from the norm, the hormone values in non-pregnant women, the rules for preparing and conducting the study.
HCG stands for Human Chorionic Gonadotropin. This substance is an important hormone produced by the tissues of the fetus when it attaches to the uterus. HCG is a hormonally active protein.
Therefore, an increase in the value of this substance usually indicates an interesting position for a woman. However, sometimes in the absence of pregnancy in women, the level can also increase. This condition is affected by various causes, including various pathologies. This hormone can also be determined in the male sex, this is due to the fact that it produces a small amount.
An analysis for hCG allows you to determine the exact period of pregnancy.
In addition, the study of this hormone will help determine whether there is a risk of various abnormalities in the formation of the fetus.The usual pregnancy test is to determine the level of the hormone in the urine. But with its help it is impossible to determine the exact timing in comparison with the study of hCG in the blood.
The main role of the hormone is to maintain and proper development pregnancy, as well as blocking menstrual cycle. In addition, human chorionic gonadotropin contributes to the activation of the synthesis of hormones that are necessary during pregnancy, namely, progesterone and estrogen.
Preparing and Performing Diagnostics
To get the correct level result, you must follow the rules for preparing for the study.
Experts advise before passing the analysis:
- Avoid sexual intercourse the day before the study.
- Do not eat or drink any liquid other than water for four to six hours.
- Limit physical and psycho-emotional overstrain.
- Inform the specialist about the use of drugs such as Pregnil, Horagon, the use of Utrozhestan and Duphaston
Blood for hCG is taken venous. To do this, treat the vein piercing area with alcohol. After that, the shoulder zone of the upper limb is clamped with a tourniquet and the required amount of blood is drawn with a syringe.
You can donate blood for a hormone from the fifth day, but according to statistics, the results are found only in 5 percent of pregnant women.
In most cases, the study shows pregnancy only on the eleventh day after fertilization.
When a pregnant woman does not know the exact day when conception occurred, it is recommended to take blood for analysis 3-4 weeks after the first day of menstruation.
Usually, experts advise to examine the blood for hormones several times at intervals of a couple of days.It is important to say that there are false results as a result of incorrect blood sampling or defective reagents.
Normal hCG by week of pregnancy
In pregnant women, the value of the hormone depends on the week of bearing the child. In this case, it is not the day of fertilization that is taken into account, but the first day of the last menstruation. Normally, an increase in the indicator for 8-11 weeks and a gradual decrease after.
Chorionic hormone is measured in honey per milliliter. The normal value for weeks during pregnancy is as follows:
- First-second: 25-300 mU/ml
- Second-third: 1500-5000 mU/ml
- Third-fourth: 10000-30000 mU / ml
- Fourth-fifth: 20000-100000 mU / ml
- Fifth-seventh: 50000-200000 mU / ml
- Eighth-ninth: 20000-200000 mU / ml
- tenth-twelfth: 20000-95000 mU / ml
- Thirteenth-fourteenth: 15000-60000 mU / ml
- Fifteenth - twenty-fifth: 10000-35000 mU / ml
- Twenty-sixth - thirty-seventh: 10000-60000 mU / ml
Description
Method of determination Linked immunosorbent assay.
Material under study Serum
Specific pregnancy hormone.
Glycoprotein is a dimer with a molecular weight of about 46 kDa, synthesized in the placental syncytiotrophoblast. HCG is made up of two subunits: alpha and beta. The alpha subunit is identical to the alpha subunits of the pituitary hormones TSH, FSH, and LH. The beta subunit (β-hCG) used for the immunometric determination of the hormone is unique.
The level of beta-hCG in the blood as early as 6-8 days after conception makes it possible to diagnose pregnancy (the concentration of β-hCG in the urine reaches the diagnostic level 1-2 days later than in the blood serum).
In the first trimester of pregnancy, hCG provides the synthesis of progesterone and estrogens, necessary to maintain pregnancy, by the corpus luteum of the ovary. HCG acts on the corpus luteum like a luteinizing hormone, that is, it supports its existence. This happens until the "fetus-placenta" complex acquires the ability to independently form the necessary hormonal background. In the male fetus, hCG stimulates the Leydig cells that synthesize testosterone, which is necessary for the formation of male reproductive organs.
The synthesis of hCG is carried out by trophoblast cells after implantation of the embryo and continues throughout pregnancy. In the normal course of pregnancy, between 2 - 5 weeks of pregnancy, the content of β-hCG doubles every 1.5 days. The peak concentration of hCG falls on the 10th - 11th week of pregnancy, then its concentration begins to slowly decrease. At multiple pregnancy the content of hCG increases in proportion to the number of fruits.
Decreased concentrations of hCG may indicate an ectopic pregnancy or threatened abortion. Determining the content of hCG in combination with other tests (alpha-fetoprotein and free estriol at 15-20 weeks of pregnancy, the so-called "triple test") is used in prenatal diagnosis to identify the risk of fetal abnormalities.
In addition to pregnancy, hCG is used in laboratory diagnostics as a tumor marker for tumors of trophoblastic tissue and germ cells of the ovaries and testes that secrete chorionic gonadotropin.
Early diagnosis of pregnancy: determining the level of hCG
What is HCG?
HCG (human chorionic gonadotropin) is a special pregnancy hormone, which is an important indicator of the development of pregnancy and its deviations. Chorionic gonadotropin is produced by cells of the chorion (shell of the embryo) immediately after its attachment to the wall of the uterus. Based on a blood test for chorionic gonadotropin, the doctor determines the presence of chorionic tissue in the body, and hence the onset of pregnancy in a woman.
When can I conduct a study to determine the level of hCG?
Determining the level of chorionic gonadotropin in the blood is the most reliable method for determining pregnancy in the early stages. Chorionic gonadotropin appears in a woman's body from 5 to 6 days after fertilization. A common rapid pregnancy test that every woman can use at home is also based on the determination of human chorionic gonadotropin in the urine, but the necessary level of this hormone in the urine to diagnose pregnancy is reached a few days later.
In the absence of any pathology, in the first weeks of pregnancy, the level of the hormone doubles every 2 days, and its maximum concentration is reached by 10-11 weeks of pregnancy. After 11 weeks, the level of the hormone gradually goes down.
An increase in the level of human chorionic gonadotropin during pregnancy can occur with:
multiple pregnancy;
toxicosis, gestosis;
maternal diabetes;
fetal pathologies, Down syndrome, multiple malformations;
incorrectly established gestational age;
taking synthetic gestagens, etc.
Elevated values can also be seen within a week when taking an analysis after the abortion procedure. A high level of the hormone after a mini-abortion indicates a progressive pregnancy.
Low level chorionic gonadotropin during pregnancy may indicate an incorrect gestational age or be a sign of serious disorders, such as:
ectopic pregnancy;
non-developing pregnancy;
delay in fetal development;
the threat of spontaneous abortion;
fetal death (in the II-III trimester of pregnancy).
Determining the level of chorionic gonadotropin is included in a triple test study, the results of which can be used to judge the presence of some anomalies in the development of the fetus, but an accurate diagnosis cannot be made. The study only allows you to identify women at risk. In this case, women will need to make a serious additional examination.
What is the role of the hCG hormone in the human body?
In addition to establishing the fact of pregnancy, by quantitative determination of the level of this hormone, one can judge the nature of the course of pregnancy, the presence of multiple pregnancy.
The most important task of human chorionic gonadotropin is to maintain the pregnancy itself. Under its control, the synthesis of the main hormones of pregnancy: estrogen and progesterone. In the first trimester, until the placenta is fully formed (up to 16 weeks), human chorionic gonadotropin maintains the normal functional activity of the corpus luteum, namely, the production of progesterone.
Another important function of human chorionic gonadotropin is to stimulate ovulation and maintain the viability of the corpus luteum.
When does a doctor prescribe an hCG test?
Beyond diagnostics early dates pregnancy, chorionic gonadotropin determine:
among women -
to detect amenorrhea;
exclusion of the possibility ectopic pregnancy;
to assess the completeness of artificial abortion;
for dynamic monitoring of pregnancy;
with the threat of miscarriage and suspected non-developing pregnancy;
for the diagnosis of tumors - chorionepithelioma, cystic drift;
for prenatal diagnosis of fetal malformations;
in men -
for the diagnosis of testicular tumors.
How to take a blood test for the hCG hormone?
The independent laboratory INVITRO offers to undergo a laboratory test to determine the level of human chorionic gonadotropin.
The analysis is given by taking blood from a vein, preferably in the morning and on an empty stomach. A laboratory test is recommended to be carried out no earlier than 4-5 days of delayed menstruation, and can also be repeated after 2-3 days to clarify the results. To identify fetal pathology in pregnant women, it is recommended to take an analysis from the 14th to the 18th week of pregnancy.
In the complex diagnosis of fetal malformations, it is also recommended to take tests to determine the following markers: AFP (alpha-fetoprotein), E3 (free estriol), as well as an ultrasound scan.
Limits of determination: 1.2 mU/ml-1125000mU/ml
Training
It is preferable to take blood in the morning on an empty stomach, after 8-14 hours of a night fasting period (you can drink water), it is permissible in the afternoon 4 hours after a light meal.
On the eve of the study, it is necessary to exclude increased psycho-emotional and physical exercise(sports training), drinking alcohol, one hour before the study - smoking.
The sensitivity of the method in most cases makes it possible to diagnose pregnancy already on the first or second day of missed menstruation, but due to individual differences in the rate of synthesis of β-hCG in women, it is better to conduct a study no earlier than a 3-5 day delay in menstruation in order to avoid false negative results. In case of doubtful results, the test should be repeated twice with an interval of 2-3 days. When determining the completeness of the removal of an ectopic pregnancy or abortion, the study of β-hCG is carried out 1-2 days after the operation to exclude a false positive result.
Interpretation of results
The interpretation of test results contains information for the attending physician and is not a diagnosis. The information in this section should not be used for self-diagnosis or self-treatment. An accurate diagnosis is made by the doctor, using both the results of this examination and the necessary information from other sources: history, results of other examinations, etc.
Units of measurement in the INVITRO laboratory: honey/ml.
Alternative units of measure: U/l.
Unit conversion: U / l \u003d honey / ml.
Reference values
Pregnant women
| Gestational age, weeks from conception | HCG level, honey / ml |
| 2 | 25 - 300 |
| 3 | 1 500 - 5 000 |
| 4 | 10 000 - 30 000 |
| 5 | 20 000 - 100 000 |
| 6 - 11 | 20 000 - > 225 000 |
| 12 | 19 000 - 135 000 |
| 13 | 18 000 - 110 000 |
| 14 | 14 000 - 80 000 |
| 15 | 12 000 - 68 000 |
| 16 | 10 000 - 58 000 |
| 17 - 18 | 8 000 - 57 000 |
| 19 | 7 000 - 49 000 |
| 20 - 28 | 1 600 - 49 000 |
Values ranging from 5 to 25 mU / ml do not allow to confirm or deny pregnancy and require a re-examination after 2 days.
Increasing hCG levels
Men and non-pregnant women:
- chorioncarcinoma, recurrence of chorioncarcinoma;
- cystic drift, recurrence of cystic drift;
- seminoma;
- testicular teratoma;
- neoplasms gastrointestinal tract(including colorectal cancer);
- neoplasms of the lungs, kidneys, uterus, etc.;
- the study was conducted within 4 - 5 days after the abortion;
- taking hCG drugs.
Pregnant women:
- multiple pregnancy (the level of the indicator increases in proportion to the number of fetuses);
- prolonged pregnancy;
- discrepancy between the real and the established gestational age;
- early toxicosis of pregnant women, preeclampsia;
- maternal diabetes;
- fetal chromosomal pathology (most often with Down syndrome, multiple fetal malformations, etc.);
- taking synthetic gestagens.
Decreased hCG levels
Pregnant women. Alarming level changes: inconsistency with the gestational age, an extremely slow increase or no increase in concentration, a progressive decrease in the level, more than by more than 50% of the norm:
- ectopic pregnancy;
- non-developing pregnancy;
- the threat of interruption (the level of the hormone decreases progressively, by more than 50% of the norm);
- chronic placental insufficiency;
- true prolongation of pregnancy;
- antenatal fetal death (in II - III trimesters).
False negative results (non-detection of hCG during pregnancy):
- the test was performed too early;
- ectopic pregnancy.
Attention! The test has not been specifically validated for use as a tumor marker. HCG molecules secreted by tumors can have both normal and altered structure, which is not always detected by the test system. The results of the test should be interpreted with caution, in comparison with clinical data and the results of other types of examination, they cannot be considered as absolute evidence of the presence or absence of the disease.
One of the most accurate methods for determining early pregnancy is a blood test for the amount of hCG hormone content. The human chorionic gonadotropin beta particle is a unique glycoprotein unit that is produced after the embryo attaches to the uterus. Its blood levels vary depending on the timing of pregnancy and play an important role in the synthesis of the hormones estradiol, progesterone and estriol. It will not be difficult for those who are interested in their “interesting” position to accurately determine the presence of pregnancy by donating blood for hCG. What it is, how the procedure goes, when to go through it and how to evaluate the results, we will consider in the article.
What is HCG?
Human chorionic gonadotropin is a hormone with a protein structure. It is produced by the tissues of the developing embryo throughout the entire period of gestation. Thanks to this substance, ovarian function is inhibited. New eggs cease to mature, and the next menstruation does not occur. HCG sets up the female body for carrying a pregnancy, contributing to the implementation of hormonal changes.
This glycoprotein consists of two units: the alpha unit is similar to other hormones in the body, while the beta unit is unique. Therefore, during the analysis, they are guided precisely by the concentration of the beta particle.
A small presence of the hormone in the human body is considered normal even in the absence of pregnancy. It is produced by the pituitary gland. Sometimes a certain amount of the hormone is found in the body of men and non-pregnant women. The norm of hCG in the blood is up to 5 mIU / ml, and for women during menopause - up to 9.5 mIU / ml.
How to determine pregnancy by blood test?
The level in a woman's body has become a universal indicator of pregnancy. Express strips are arranged just according to this principle. They respond to the level of the hormone in the urine, which begins to increase markedly as early as 2 weeks after fertilization. However, the tests are not always accurate, and besides, with their help it is impossible to accurately tell the gestational age. Therefore, women who are planning to conceive are advised to donate blood for hCG. What's this? A common procedure performed in any private or public laboratory.
The results obtained are highly accurate. Many women are interested in the question: “When will blood on hCG show pregnancy?” Obstetricians and gynecologists recommend taking your time and thinking about conducting an analysis only after a delay. The minimum period after which it is possible to determine pregnancy is 7 days from the moment of conception.
When can I donate blood for hCG?
Despite the fact that a blood test is a highly accurate and affordable method that allows you to find out about pregnancy, you should think about the timing of it. Of course, nothing prevents you from contacting a diagnostic laboratory within a couple of days after conception. But the results of such an analysis will not be reliable. And yet, when can you donate blood for hCG in order to get accurate pregnancy data? Doctors recommend the following terms:
- if a woman knows exactly the day of conception, then 2 weeks must be counted from it. On the received date and schedule the analysis;
- in cases where it is impossible to determine the moment of conception, it is considered advisable to take an analysis after 3 weeks from the day of the delay in menstruation.
To obtain reliable results, you should be patient and wait for the recommended time.
How to take an analysis and how much does it cost?
Women inexperienced in matters of pregnancy and motherhood ask many questions about the analysis. How to take hCG, what rules must be followed? In fact, everything is much simpler than it seems. Blood for hCG is taken from the cubital vein in the amount of 5 ml. It is advisable to come to the analysis in the morning and do not eat anything before the procedure. Before getting a referral from a doctor, it is better to warn about taking medications. This may affect the results of the study.
What is the cost of the "blood for hCG" analysis? The price may vary depending on the laboratory. On average, the service will be 500 rubles, in the capital - about 800 rubles. This applies to private clinics and diagnostic centers. IN budget institution at the place of residence, the referral is issued free of charge.
Interpretation of primary results
Having decided when it is better to donate blood for hCG, having gone through the procedure and having received the coveted result, I want to know more about what the numbers on the analysis statement mean. Three scenarios are possible:
- Negative - the hormone is defined as 0 to 5 mIU/ml.
- Doubtful - chorion indicators are fixed in the range of 5-25 mIU / ml.
- Positive - hCG in the blood exceeds 25 mIU / ml.
If a questionable result is obtained (a slight increase in the hormone), it is recommended to re-analyze after a few days. At the same time, it is desirable to comply with the same conditions for blood sampling and diagnostics: to come to the same clinic, at the same time of day and on an empty stomach. New result compared with the previous one. If the deviation in one direction or another is preserved and exceeds 50% of the norm, a conclusion is made about the presence of a pathological process (a sign of tumors). In the case of a 20% deviation from the established values, the result is again called into question, appointing a new study. In some cases, with the stability of the results and the absence of pathologies, a conclusion is made about the individual level of the chorion hormone in the blood.
A single analysis is performed only if a negative result is obtained, in which there is no doubt over time. When pregnancy is confirmed, it is necessary to periodically monitor the blood hCG hormone.
Changes in test results by week of pregnancy
In the first weeks of pregnancy, the level of the hormone chorion in the blood increases significantly. The growth rate is considered in days required to double it:
- up to 6 weeks - 2;
- 6-8 weeks - 3;
- 8-10 weeks - 4.
By the 11th week of pregnancy, the result of a blood test for hCG will show the maximum value. After that, a gradual decline will begin. At 16 weeks, the indicator will be identical to a 7-week pregnancy. In the remaining period of gestation, the level of the hormone will remain stable.
Week from conception | HCG level, mIU/ml |
The variation in the level of the chorionic hormone is very high: all options in the specified range are considered normal. In addition, only a doctor can reliably interpret the results. Sometimes the individual bar of the hormone in the blood is slightly higher or lower than the standard.
HCG indicators during IVF
If a woman has undergone an IVF procedure, then the procedure for conducting the analysis will change somewhat. When will blood on hCG show pregnancy in this case? The answer of the experts is as follows: the procedure should be completed no earlier than 12 days after the injection with the content of the hormone chorion. The table shows the average values of hCG in the blood after implantation of the embryo into the uterine cavity.
Average hCG value, mIU/ml |
|
How to take hCG if injections with its content were prescribed after implantation of the embryo in order to maintain the functioning of the corpus luteum? You should wait a few days before doing the analysis. Otherwise, the results will be overestimated.
High levels of hCG in the blood
Most pregnant women are practically unaware of what theirs is. If everything is in order, the doctor rarely tells the expectant mother about the results of each examination. Another thing is when problems arise. HCG in the blood may be higher or lower than normal. And only with rare exceptions, this does not indicate the pathology of the development of the fetus or the health of the mother.
What do the overestimated numbers in the results of the analysis for hCG hide behind? Sometimes nothing serious: incorrect setting of the term or multiple pregnancy. However, suspicion often falls on the presence of a woman diabetes, toxicosis or pathologies in the development of the embryo. If an elevated level of hCG in the blood is detected, a second analysis and an additional examination of the expectant mother are prescribed.
Low levels of hCG
The level of the chorion hormone in a woman's blood allows not only to detect pregnancy in the early stages with high accuracy, but also to monitor the development of the embryo throughout the entire period of gestation. HCG is a specific hormone of motherhood. Its underestimated indicators, as a rule, indicate violations of the course of pregnancy:
- the threat of miscarriage;
- delay in the development of the embryo;
- fetal death;
- "fading" of the embryo;
- ectopic pregnancy;
- pathology of the placenta or fetus.
Any deviation from the norm in the results of the analysis for hCG is an alarming sign that requires immediate medical attention for advice.
Should we rely on the results of the analysis?
And yet, blood for hCG - what is it? How much can you trust a typical laboratory analysis? This procedure is similar to the fence because hCG is one of them. The reliability of the result is at a high level: inaccuracies rarely occur, usually due to the reception medicines or the use of specific foods on the eve of the analysis.
Laboratory studies may give a false positive or false negative response. In the first case, a high level of hCG, typical for a pregnant woman, will be determined. Only after a while it turns out that the embryo is absent in the uterine cavity. Why it happens? There are few options: either the drugs taken by the woman are to blame (including those containing hCG), or this is a serious sign of pathology.
A false negative result usually occurs when testing is done too early. There are also anomalies in the development of the embryo in the early stages. In any case, a second analysis and ultrasound are prescribed.
conclusions
Blood for hCG - what is it? It turns out to be a standard and very informative analysis. With its help, it is possible to diagnose pregnancy with high accuracy already after 2 hCG - a specific hormone produced by the tissues of the chorion (subsequently the placenta). After entering the uterine cavity, its amount increases sharply, stimulating the restructuring of the body for bearing the fetus. HCG indicators are the best way to characterize pregnancy and notify in time future mother not only about the "interesting" situation, but also about failures in the development of the baby.
One of the most used and widely known methods of early diagnosis of pregnancy is a pregnancy test based on the detection of human chorionic gonadotropin (hCG) in the urine. At the same time, even more useful information can be obtained by determining the level of hCG in the blood. In what cases is this analysis prescribed and how to properly donate blood for hCG - let's figure it out.
HCG in blood and urine
Human chorionic gonadotropin (hCG) is the most important hormone that is produced by the membranes of the embryo and fetus (first by the chorionic villi, and then by the placenta) from the moment a fertilized egg is implanted into the uterine wall until delivery.
During the first 2-3 months of pregnancy, the concentration of hCG in the blood increases progressively - normally, the indicator doubles every 2 days. From the 12th to the 16th week, the concentration of the hormone gradually decreases, from the 16th to the 34th it remains at a constant level, and after the 34th week there is a repeated increase in the concentration of hCG in the blood, which is considered as a possible mechanism for preparing the mother's body for childbirth.
HCG ensures the preservation and development of pregnancy and plays an important role in stimulating and maintaining the normal synthesis of sex hormones - estrogens and progesterone, the action of which is also aimed at creating conditions for the optimal course of pregnancy. After synthesis by the cells of the fruit membranes, hCG enters the mother's blood, and from there into the urine. That's why hCG tests in the blood and urine - one of the reliable ways to diagnose pregnancy.
It should be said that not only the placenta and embryonic membranes are a potential source of hCG in the blood. Certain amounts of this hormone can be synthesized by hormone-producing tumors (for example, chorionepithelioma, some testicular tumors), and also (in postmenopausal women) by special cells of the pituitary gland.
HCG in blood and urine difference
Immediately after the start of the synthesis of hCG by the membranes of the embryo, the hormone enters the woman's blood, where it realizes its physiological effects. Therefore, hCG in the blood of a pregnant woman appears already on the day of implantation of the egg - that is, on the 7-8th day from conception. At the same time, for the hormone to appear in the urine, it is necessary that the level of hCG in the blood reaches certain values, which occurs no earlier than 10-14 days after conception. That is, the main difference between tests for hCG in urine and blood is that pregnancy can be determined by blood a few days earlier. Therefore, hCG in the blood is considered the earliest marker of pregnancy.
HCG blood test
A blood test for hCG is performed in a laboratory. For this, the woman's blood is used, from which plasma (serum) is obtained, and then examined using a special analyzer. In general, the analysis (from the moment of blood sampling to the receipt of the result) can take from one to several days (the exact timing depends on the workload and workflow of a particular laboratory).
How to donate blood for hCG
To obtain the most reliable test results, it is very important to know how to properly donate blood for hCG. The concept of "correct donation" in this case implies the date of blood donation, the features of preparation for analysis and the choice of a place for taking blood for analysis for hCG.
When can I donate blood for hCG
If a blood test for hCG is prescribed to diagnose early pregnancy, blood can be donated starting from the 8th day after conception. However, at this time, the concentration of the hormone in the blood may be too low and the result may be false negative or doubtful. Therefore, it is best to donate blood after 1-2 days of delayed menstruation.
In some cases (when donating blood before a missed period, to exclude a missed or ectopic pregnancy), the doctor prescribes a triple test, that is, blood for hCG in this case must be taken three times with an interval of 2-3 days (preferably at the same time of day ). An adequate increase in the concentration of the hormone in the blood will mean that the pregnancy is developing normally. The absence of a normal increase in the indicator will show that there may be problems with pregnancy.
If an hCG blood test is performed to confirm the success of an operation for an ectopic pregnancy or medical abortion, blood for analysis is taken 1-2 days after the operation/abortion.
If blood for hCG is taken for other indications (for example, to detect certain tumors or monitor the course of pregnancy), you can take an analysis on any day that is convenient for the patient / patient.
Blood for hCG during pregnancy
It should be said that blood for hCG during pregnancy is examined not only for the early diagnosis of pregnancy. A very important test is a blood test for hCG, which is performed in the first and second trimesters of pregnancy for the purpose of biochemical prenatal screening for the presence of defects (chromosomal abnormalities) in the fetus. Also, an analysis for hCG during pregnancy can be performed at any time to track the progression of pregnancy.
What day to donate blood for hCG
Biochemical screening of the 1st trimester of pregnancy is carried out at a period of 11 weeks - 13 weeks 6 days, screening of the 2nd trimester - at a period of 16-18 weeks of pregnancy. Usually, blood for hCG (and other markers of chromosomal abnormalities - free estriol, alpha-fetoprotein, PAPP-A protein) is taken on the same day when the obligatory screening ultrasound of the fetus of the 1st and 2nd trimesters is performed.
When to donate blood for hCG before the delay
As mentioned above, hCG appears in the blood of a woman already 7-8 days after conception, that is, about a week before the delay in menstruation. However, this week the levels of the hormone in the blood are so low that they may not be detected even by highly sensitive laboratory analyzers, which creates the possibility of obtaining a false negative result. Therefore, women who donated blood for hCG for the first time before the delay in menstruation must definitely repeat this analysis at least 2 more times with an interval of 2-3 days in order to get a reliable result.
Where do they get blood for hCG
To analyze for hCG, venous blood is used, which is obtained using standard methods. Usually, the vein of the elbow bend is used for this, that is, a vessel that passes shallowly under the skin in the area of \u200b\u200bthe inner bend of the elbow of the arm. If the veins in the elbow area are deep or have a structure that makes it difficult to draw blood, the laboratory technician can use the veins on the hand or other superficially located venous vessels.
Blood on hCG on an empty stomach or not
Blood for analysis for hCG is taken on an empty stomach - that is, after an 8-10-hour overnight fast. If you have to donate blood during the day (not in the morning), you must refrain from eating for at least 4 hours before taking the sample.
Blood for hCG when pregnancy shows
The most reliable result of a blood test for hCG for diagnosing pregnancy can be obtained on the 3rd-5th day of a delay in menstruation and more. late dates. Given these realities, women planning a pregnancy are not recommended to donate blood for hCG too early - this will save them from unnecessary worries associated with false negative test results.
The level of hCG in the blood
When deciphering the results of a blood test for hCG, it is necessary to take into account the gender, age of the patient, indications for analysis, as well as the units of measurement and normal limits used by the laboratory. Only compliance with all these conditions will allow you to get useful information from the result of a blood test for hCG, therefore, a qualified doctor should deal with the decoding of the result of the analysis.
Below are the normal values for the level of hCG in the blood of adult women and men, used by the largest laboratories in Ukraine. We emphasize once again that only the attending physician can use these values to interpret the result of the analysis. These figures are provided in this article for informational purposes only.
HCG by day from conception in the blood
In the first 3 weeks of pregnancy, counting from the moment of conception, the level of hCG in the blood normally changes as follows:
- 6-8th day - 5-50 mIU / ml;
- 7-14th day - 50-500 mIU / ml;
- Days 14-21 - 101-4870 mIU / ml.
If the result of a blood test for hCG falls within these limits, then the pregnancy exists and it develops normally.
HCG in the blood by day
The following indicators are used for monitoring the course of pregnancy and prenatal screening for fetal malformations / anomalies:
| week of pregnancy | HCG level (mIU / ml) |
|---|---|
| 3rd week | 5,8-71,2 |
| 4th week | 9,5-750,0 |
| 5th week | 217,0-7138,0 |
| 6th week | 158,0-31795,0 |
| 7th week | 3697,0-163563,0 |
| 8th week | 32065,0-149571,0 |
| 9th week | 63803,0-151410,0 |
| 10-11th week | 46509,0-186977,0 |
| 12th -13th week | 27832,0-210612,0 |
| 14th week | 13950,0-62530,0 |
| 15th week | 12039,0-70971,0 |
| 16th week | 9040,0-56451,0 |
| 17th week | 8175,0-55868,0 |
| 18th week | 8099,0-58176,0 |
The norm of hCG in the blood
In the blood of non-pregnant women normal level hCG is
When to donate blood for hCG
The main indications for a blood test for hCG are:
- diagnosis of early pregnancy;
- diagnosis of ectopic pregnancy; - prenatal screening of the fetus for the presence of malformations and chromosomal abnormalities;
- exclusion of missed pregnancy;
- suspicion of a threatened abortion;
- control over the development of pregnancy;
- suspicion of some tumor diseases in men (testicular tumor) and women (chorionepithelioma, choriocarcinoma);
- evaluation of the result of surgery for ectopic pregnancy and medical abortion;
- diagnostics, control of efficiency and dynamic observation after trophoblastic disease.
Blood for hCG decoding
In men and non-pregnant women, only an increase in hCG levels has diagnostic value. Increase in hCG above the upper limit of normal in this group of people may indicate:
- the presence (relapse) of choriocarcinoma or cystic mole (women);
- the presence of seminoma or testicular teratoma (men);
- the presence of a tumor of the gastrointestinal tract, lungs, kidneys, uterus.
Among women elevated levels HCG can be determined within 4-5 days after an abortion, as well as while taking hCG preparations.
During pregnancy, both an increase and a decrease in the level of hCG are important.
Increase in hCG may indicate the presence of multiple pregnancy; prolonged pregnancy; the presence of early preeclampsia or diabetes in a pregnant woman, the presence of Down syndrome in the fetus or multiple malformations. Also, an increase in the level of hCG in the blood of pregnant women (above the level normal for a given gestational age) is possible with an incorrect determination of the gestational age and against the background of taking hormonal drugs in order to prevent abortion.
Decreased hCG levels during pregnancy may be associated with the presence of an ectopic or missed pregnancy, the threat of abortion, placental insufficiency, prolonged pregnancy and intrauterine fetal death.
A change in the level of this substance in a woman's body can occur already on the seventh day after conception when the embryo Starting from this time, the fact of conception can be confirmed by, based on detection in the urine.
What is HCG
Human chorionic gonadotropin (hCG) is a hormone whose production is greatly increased after embryo attachment. This substance is produced by the germinal membrane ( chorion), which subsequently Hence the name of the hormone - "chorionic".
Term "gonadotropin" in the name of this substance means that this hormone has an effect on female reproductive organs - gonads(the common name for the genital organs in humans and animals).
Human chorionic gonadotropin affects, as a result of which the woman's body increases and thus protects the embryo until the placenta begins to function.
Determining the level of hCG
The easiest way to determine the level of hCG in order to establish the fact of pregnancy is to use it, which can be purchased at a pharmacy. This method of research, although it is considered very affordable and inexpensive, therefore it is desirable to undergo further examination in a medical institution.
When determining the level of this hormone in the blood by a laboratory method, you can:
- confirm or deny a possible pregnancy;
- it is quite accurate to establish the level of the hormone in the woman's body, which allows timely identification of possible deviations in the development of the embryo (fetus).
As a rule, the level of hCG is measured in honey/ml or mIU/ml- this means the content in 1 ml of milli international units.
important The content of hCG in a woman's body constantly increases until 10-11 weeks, then begins to decline sharply due to the fact that it takes on important functions to protect the fetus from the influence of negative factors.
Table - Approximate norms for the content of hCG during pregnancy
| week of pregnancy | The norm of hCG, honey / ml |
| no pregnancy | 0 to 5 |
| 1 | from 16 to 56 |
| 2 | from 101 to 4870 |
| 3 | from 1110 to 31500 |
| 4 | from 2560 to 82300 |
| 5 | from 23100 to 151000 |
| 6 | from 27300 to 233000 |
| 7-10 | from 20900 to 291000 |
| 11-15 | from 6140 to 103000 |
| 16-20 | from 4720 to 80100 |
| 21-25 | from 2700 to 35000 |
| 26-39 | from 2700 to 78000 |
Deviation from the norm
In some cases, the actual indicators of human chorionic gonadotropin in the blood of a woman are somewhat different from the normative ones.
information In such a situation, it is required additional examination in order to determine the cause of the violation.
In comparison with the norm during pregnancy, it is observed in the following cases:
- some (for example, ).
During the bearing of the baby, it may occur as a result of exposure to the following reasons.
