- Pregnancy test
- When and how to take
- By days from conception
- Weekly rates
Sometimes a woman has an urgent need to find out if she is pregnant as soon as possible. Some rush to the nearest pharmacy to buy test strips in the hope of seeing the result on them even before the next period is delayed, but there is a more accurate and informative way to find out if there is a pregnancy at the earliest possible date - to donate blood for hCG.
What it is?
HCG or hCG is a hormone that begins to be produced in the body by cells of such an embryological structure as chorion. This happens after the fertilized egg is implanted.
The first 6-8 days after conception, it moves into the uterine cavity through the tube, and these days human chorionic gonadotropin (this is the full name of the substance) is not produced.
Once the egg is implanted, the chorionic tissues begin to produce doses of HCG. The hormone is necessary so that all conditions for the development of an attached embryo are created in the female body. The hormone suppresses the processes normal for changing the phases of the menstrual cycle, because they are not necessary for the next nine months. In addition, under the influence of this protein hormone, the corpus luteum begins to produce huge amounts of progesterone, androgens and estrogen. These substances help to maintain and successfully transfer pregnancy... Chorionic gonadotropic hormone causes changes in the functioning of the adrenal cortex, which leads to the necessary physiological immunosuppression in this case.
If the woman's immunity is not suppressed, then it can reject the embryo, which is 50% foreign in terms of genetic makeup. It is hCG that provides some reduction in immune responses aimed at preserving the child. Later, when the placenta is formed, this hormone promotes its development, improves the vascular permeability of the placenta. In women outside pregnancy and in men, such a hormone may appear in the blood during some tumor processes in the body, and these neoplasms are most likely to be malignant.
By the way, pregnancy test strips so beloved by women and girls are based on the peculiarities of the pregnant female body, which is also called "pregnancy hormone", which can be bought at any pharmacy and in any store. True, it should be understood that the test is designed to determine hormone in urine, and in it it appears in the required amount much later than in the blood... Therefore, a blood test can give a reliable result earlier than a pharmacy pregnancy test.
Why is this analysis needed?
In addition to satisfying a simple female curiosity - is there a pregnancy or not, the level of hCG can tell a lot. A blood test for hormone concentration is prescribed to find out if the pregnancy is multiple (Each embryo produces a certain amount of hormonal "accompaniment", and the level of the substance in the blood of the expectant mother depends on the number of embryos. Blood for hCG is donated during the periods of prenatal screenings - at 11-13 weeks and at 16-19 weeks of pregnancy, in order to find out how large the child has the risk of being born with severe gross chromosomal malformations.)
A woman is sent for such an analysis if a woman is suspected of a frozen pregnancy, a delay in fetal development, an ectopic pregnancy, since the concentration of a substance in the blood can indicate both the progressive development of the baby and his death. The analysis is considered mandatory for women who have had an abortion (both medical and conventional). The rapidly decreasing level of this gonadotropic hormone will be able to inform the attending physician about how successful the curettage was. All non-pregnant women and men donate blood for HCG if malignant tumors are suspected, especially testicular tumors in the stronger sex.
When can I take it?
The level of chorionic gonadotropin in the body of a woman who will soon become a mother doubles every two days. Considering that it takes about a week for the unborn baby to get to the attachment site.
The first laboratory data on an increase in hCG in the blood can be obtained approximately 10 days after fertilization.
This is 4-5 days earlier than the pharmacy tests can show the second strip. The sensitivity of such tests to the hormone is 2 times lower, and the concentration of the hormone in the urine increases twice as slowly as in the blood. Thus, if we take as a basis the fact that the level of hCG in a non-pregnant woman does not exceed 5 mU / ml, then it is clear that on the second day after implantation (9-10 days after fertilization) the level of the hormone will rise to 10 mU / ml, and also after 2 days - up to 20 mU / ml. By 14 days after conception, the level will be about 40-60 mU / ml. In the urine of chorionic gonadotropin, about 30 mU / ml will be determined, which exceeds the sensitivity threshold of the pharmacy test strip (15-20 mU / ml, depending on the manufacturer), and the woman will be able to see two strips.
However, tests can give incorrect results, be defective, or run with errors. With a blood test, everything is much more accurate.
It not only determines the fact of a completed pregnancy, but also indicates the period, the well-being of the development of the embryo, as well as the possibility of developing not one baby, but several at once.
It is impossible to determine pregnancy by a general blood test; a biochemical study of the woman's venous blood is required. And it should be taken no earlier than 10-12 days after ovulation. The possibility of late implantation should also be taken into account, when the fertilized egg descends into the uterine cavity and is fixed there not on 7-8 days after conception, but only after 10 days. Then a blood test will show pregnancy only 14 days after ovulation.
The theoretical and practical opportunity to find out whether conception took place even before the delay in menstruation is only with the help of laboratory diagnostics of blood for the content of hCG in it.
How to pass correctly?
Many things can affect the reliability of the analysis result - colds and infectious diseases that a woman has, her dietary habits, severe stress. Therefore, before surrendering it is recommended to prepare yourself for early diagnosis... You need to make sure that there is no fever, signs of viral or other diseases.
If a woman wants to determine pregnancy before her period is delayed, then she should provide for the possibility of repeated blood donations, since it is the results in dynamics that will be important. It is advisable to take a break of 2 days between the initial and re-delivery.
A day before visiting the laboratory, a woman should refrain from fatty and fried foods, an abundance of spices and sweets so that nutrition does not affect the composition of the blood.
It is advisable to take the last meal no later than 6-8 hours before the analysis; you should come to a medical institution on an empty stomach in the morning.
If a woman has taken any hormonal medications in the last 2 weeks, then this must be reported before taking the test.
The result can be expected in a few hours or a few days - it depends on the pace of work and the workload of the laboratory. If a woman goes to a private clinic and does the analysis for a fee, then there is every chance of getting the result the same evening or even earlier.
How to understand the result?
None of the laboratory assistants will explain to a woman what the numbers mean as a result of her analysis, since a doctor should do this. However, a woman does not always have an appointment with a gynecologist on the same day, and I want to understand what the blood tests have shown right now. It is difficult to give uniform norms for the concentration of hCG, since each laboratory has its own numbers. However, there are certain approximate standards that can speak not only about the fact of pregnancy, but also about its possible term.
Since with multiple pregnancies, the body's hormonal support is double, the results of hCG during pregnancy with twins or triplets will significantly exceed the above values \u200b\u200b(in proportion to the number of children).
It is not worth doing a second analysis, if necessary, in another laboratory, since comparison of two different analyzes is not permissible. You need to re-pass the examination in the same laboratory as the first time.
Possible mistakes
The accuracy of this analysis is high, which is why the examination technique has found such widespread use in medicine, especially in gynecology and obstetrics. However, no one is immune from mistakes, so you should consider the likely erroneous results.
False positive result - there is hCG, but there is no pregnancy
Elevated gonadotropin levels can be found in women who have been taking hormonal drugs or undergoing fertility treatment. Also, the level of the hormone may be increased during tumor processes in the body. If the result is in doubt, it is advisable to donate blood again after 4-6 days. If the level of the hormone does not grow or grows very slightly, there is no pregnancy, you should look for the true cause of the change in hormonal levels.
Often, a woman can get a negative result at home using a test strip, but hCG in the blood will turn out to be high, and this indicates that there is a pregnancy, it is just that its term is still so short that the hormone is not detected in the urine.
False negative result - there is no hCG, but there is pregnancy
A pregnant woman can also get a negative result from the laboratory. This becomes possible if she is too early for examination - the implantation has not yet taken place, the hormone is not produced. Too early is a very specific concept - up to 10-12 days after ovulation, and preferably up to 14 days after it, there is nothing to do in the laboratory. Negative or weakly positive can also be a result in which the level of hCG is significantly lower than the level that should be at a given time. In this case, doctors may suspect an ectopic pregnancy, pregnancy does not develop. A careful study of blood dynamics is required (every 2 days), and a little later - an ultrasound diagnosis to establish the place of attachment of the ovum and its viability.
Common questions
The topic of chorionic gonadotropin has been allocated many pages of women's forums on the Internet. Perhaps no other hormone in the human body is of such keen interest. Here are short answers to the most common questions girls and women have about hCG.
How long does HCG show?
Numerical values, as already mentioned, are different in each laboratory, and time tables are also their own. However, it should be understood that all tables without exception are based on compliance with the embryonic date, and not obstetric. Obstetric is measured from the first day of your last menstrual period. Embryonic - from the day of conception... Thus, if a blood test for the content of chorionic gonadotropin showed that a woman has 2-3 weeks of pregnancy, this means that, by obstetric standards, she has 4-5 weeks, and from the day of the delay, from several days to 1 week has passed.
HCG increased
If at the earliest stages, hCG shows a significant excess of the norms for gestational age, then it is highly likely that a woman conceived twins. Also, an increased level of the hormone is characteristic of women with diabetes.
HCG lowered
If a woman has every reason to claim that she knows the exact date of conception, and the hCG level in the first analysis indicates that the actual embryonic period is less, then we can talk about an ectopic attachment of the ovum, about the threat of miscarriage at the earliest possible date.
HCG negative after positive
The first blood test for pregnancy could show positive results, but after a week the results are negative. Unfortunately, this happens quite often. Fertilization took place, implantation in the uterine cavity took place, but for some internal reasons, the ovum stopped developing, and the level of the corresponding chorionic hormone dropped.
If a woman did not donate blood at all for laboratory diagnostics, everything would look like menstruation, which came with a strong delay (by a couple of weeks), which went a little more painful than usual, with the appearance of blood clots. Many women in such situations do not even know that they have had a pregnancy.
Is this analysis required?
A mandatory blood test for hCG for all pregnant women is only twice during the entire period of bearing a child - during the first and second screening, they take place at 11-13 weeks, and then at 16-19 weeks. The rest of the time, a blood test for the concentration of chorionic gonadotropin is not mandatory. There are categories of women who are recommended to take this analysis over time.
These include those who become pregnant with IVF (in vitro fertilization), women who have previously had missed pregnancies and miscarriages in the earliest stages, and are pregnant with twins or triplets.
If you choose how to independently diagnose pregnancy early on in the pre-medical order, then the choice remains with the woman. Pharmacy tests often give unreliable results, and they begin to "strip" after a delay. But they are inexpensive and available at any time.
To take a blood test, you need to find a clinic, make an appointment, prepare and donate blood. All this, of course, is paid. The cost of analysis on average in Russia is from 550 to 700 rubles, but the accuracy of the study is higher, and there is an opportunity to find out about the "interesting position" even before the delay of menstruation.
How does the hormone in the blood grow after fertilization?
Women who are very much looking forward to the onset of pregnancy, the entire second half of their monthly cycle is already routinely measured in DPO - days after ovulation. They measure the basal temperature, draw graphs, almost a day after the alleged conception, they begin to buy pharmacy tests, trying to see at least some signs of the second stripe on a completely negative strip.
In order not to get nervous herself, not to jerk loved ones and not to escalate the situation, you should know that hCG will increase to about 4mU / ml only on the 7th day after ovulation... Such a value is not able to catch the test strips, and laboratory analysis at this time will give an unambiguous negative result. At 9 DPO (day after ovulation), the level of gonadotropin rises to 11 mU / ml. This is also not enough for a full-fledged diagnosis with a home test, but already 2 times more than the “non-pregnant” norm in the blood.
At 11 DPO, the concentration of the hormone is on average from 28 to 45 mU / ml, which is already determined in the laboratory without problems. By the first day of delay (at 14 DPO), the hormone is in a sufficiently high concentration (105-170 mU / ml), and this level can be easily detected by both urine stripes and test laboratory reagents in the blood.
Do I need a blood test after ovulation stimulation?
If a drug of the same name ("Chorionic Gonadotropin") is used to stimulate follicle rupture, then after an injection and sexual intercourse, you should not rush to the clinic to donate blood. A woman's body needs about 10 days to get rid of the "pricked" hormone, otherwise a false-positive test result is ensured - the hormone will be found in the blood, but there may not be pregnancy.
You can learn more about the analysis of hCG from the following video.
- Pregnancy test
What is Human Chorionic Gonadotropin (HCG)?
Human chorionic gonadotropin is a special hormone protein that is produced by the membranes of the developing embryo during the entire period of pregnancy. HCG supports the normal development of pregnancy. Thanks to this hormone, the processes that cause menstruation are blocked in the body of a pregnant woman and the production of hormones necessary to maintain pregnancy increases.
An increase in the concentration of hCG in the blood and urine of a pregnant woman is one of the earliest signs of pregnancy.
The role of hCG in the first trimester of pregnancy is to stimulate the formation of hormones necessary for the development and maintenance of pregnancy, such as progesterone, estrogens (estradiol and free estriol). With the normal development of pregnancy, these hormones are subsequently produced by the placenta.
Chorionic gonadotropin very important. In a male fetus, chorionic gonadotropin stimulates the so-called Leydig cells, which synthesize testosterone. Testosterone in this case is simply necessary, as it promotes the formation of male genital organs, and also affects the adrenal cortex of the embryo. HCG is composed of two units - alpha and beta-hCG. The alpha component of hCG has a similar structure to the units of the hormones TSH, FSH and LH, and beta-hCG is unique. Therefore, in the diagnosis, laboratory analysis of b-hCG is of decisive importance.
Small amounts of human chorionic gonadotropin are produced by the human pituitary gland even in the absence of pregnancy. This explains the fact that in some cases very low concentrations of this hormone are determined in the blood of non-pregnant women (including women during menopause) and even in the blood of men.
Acceptable blood levels of hCG in non-pregnant women and men
How does the level of human chorionic gonadotropin change during pregnancy?
With the normal development of pregnancy, hCG is determined in the blood of pregnant women from about 8-11-14 days after conception.The hCG level rises rapidly and, starting at 3 weeks of pregnancy, doubles approximately every 2-3 days. The increase in the concentration in the blood of a pregnant woman continues until about 11-12 weeks of pregnancy. Between 12 and 22 weeks of gestation, the concentration of hCG decreases slightly. From week 22 and before delivery, the concentration of hCG in the blood of a pregnant woman begins to increase again, but more slowly than at the beginning of pregnancy.
By the rate of increase in the concentration of hCG in the blood, doctors can determine some deviations from the normal development of pregnancy. In particular, with an ectopic pregnancy or a frozen pregnancy, the rate of increase in the concentration of hCG is lower than in a normal pregnancy.
An accelerated rate of increase in the concentration of hCG may be a sign of cystic drift (chorionadenoma), multiple pregnancies, or fetal chromosomal disorders (for example, Down's disease).
There are no strict guidelines for the content of hCG in the blood of pregnant women. The level of hCG at the same gestational age can vary significantly from woman to woman. In this regard, single measurements of the hCG level are not very informative. To assess the development of pregnancy, the dynamics of changes in the concentration of chorionic gonadotropin in the blood is important.
Days since your last period | Gestational age | Nomes of the hCG level for this period mU / ml |
Human chorionic gonadotropin norm graph
Norms of human chorionic gonadotropin in blood serum
Note!
In the last table, weekly rates are given for the timing of pregnancy "from conception" (and not for the timing of the last menstruation).
Anyway!
The above figures are not a benchmark! Each laboratory can set its own standards, including by week of pregnancy. When assessing the results of the hCG norm by weeks of pregnancy, you need to rely only on the norms of the laboratory where you were analyzed.
Tests to determine the level of hCG
To determine the level of hCG, various laboratory blood tests are used, which can detect pregnancy at a period of 1-2 weeks.The analysis can be passed in many laboratories in the direction of a gynecologist and independently. No special preparation for the delivery of a blood test is required. However, before getting a referral for a test, be sure to tell your doctor about all the medications you are taking, as some medications can affect the test results. The analysis is best done in the morning on an empty stomach. For higher reliability of the test, it is recommended to exclude physical activity on the eve of the study.
By the way, home rapid pregnancy tests are also based on the principle of determining the level of hCG, but only in the urine, not in the blood. And it should be said that compared to a laboratory blood test, this one is much less accurate, since the level in the urine is two times lower than that in the blood.
A laboratory test for determining pregnancy in the early stages is recommended not earlier than 3-5 days of delayed menstruation. The pregnancy blood test can be repeated 2-3 days later to verify the results.
To identify fetal pathology in pregnant women, an analysis for chorionic gonadotropin is taken from 14 to 18 weeks of pregnancy. However, in order for the diagnosis of possible fetal pathologies to be reliable, it is necessary to pass more than one blood test for hCG. Together with hCG, the following markers are deposited: AFP, hCG, E3 (alpha-fetoprotein, human chorionic gonadotropin, free estriol.)
Serum AFP and CG levels in physiological pregnancy
| Pregnancy period, weeks | AFP, medium | AFP, min-max | HG, intermediate | HG, min-max |
|---|---|---|---|---|
| 14 | 23,7 | 12 - 59,3 | 66,3 | 26,5 - 228 |
| 15 | 29,5 | 15 - 73,8 | ||
| 16 | 33,2 | 17,5 - 100 | 30,1 | 9,4 - 83,0 |
| 17 | 39,8 | 20,5 - 123 | ||
| 18 | 43,7 | 21 - 138 | 24 | 5,7 - 81,4 |
| 19 | 48,3 | 23,5 - 159 | ||
| 20 | 56 | 25,5 - 177 | 18,3 | 5,2 - 65,4 |
| 21 | 65 | 27,5 - 195 | ||
| 22 | 83 | 35 - 249 | 18,3 | 4,5 - 70,8 |
| 24 | 16,1 | 3,1 - 69,6 |
Can the analysis for hCG "be wrong" in determining pregnancy?
HCG indicators that go beyond the norm for a particular week of pregnancy can be observed if the gestational age is incorrectly determined.Laboratory analyzes can be wrong, but the chances of error are very small.
Decoding
Normally, during pregnancy, the level of chorionic gonadotropin gradually increases. During the 1st trimester of pregnancy, the level of b-hCG increases rapidly, doubling every 2-3 days. At 10-12 weeks of gestation, the highest hCG level in the blood is reached, then its content begins to decrease slowly and remains constant during the second half of pregnancy.An increase in beta-hCG during pregnancy can occur when:
- multiple pregnancies (the rate increases in proportion to the number of fruits)
- toxicosis, gestosis
- maternal diabetes
- fetal pathologies, Down syndrome, multiple developmental defects
- incorrectly set gestational age
- taking synthetic gestagens
- production of hCG by the pituitary gland of the examined woman; testicular tumor
tumor diseases of the gastrointestinal tract
neoplasms of the lungs, kidneys, uterus
cystic drift, recurrence of cystic drift
chorionic carcinoma
taking hCG drugs
analysis was done within 4-5 days after the abortion, etc.Chorionic gonadotropin is usually elevated if the test was performed 4–5 days after the abortion or as a result of taking hCG drugs.
Low hCG in pregnant women, it can mean an incorrect setting of the term for determining pregnancy or be a sign of serious violations:
- ectopic pregnancy
- undeveloped pregnancy
- delayed fetal development
- the threat of spontaneous abortion (reduced by more than 50%)
- chronic placental insufficiency
- true prolongation of pregnancy
- fetal death (in the II-III trimester of pregnancy).
Whatever the result of the analysis for hormones during pregnancy does not turn out, remember that only a qualified doctor can give the correct decoding, determining which hCG is the norm for you, in combination with the data obtained by other examination methods.
Video. Prenatal Screening - HCG
During pregnancy, a restructuring of all biological processes occurs. A new hormone appears in the body of the expectant mother - human chorionic gonadotropin (hCG). Its growth is rapid, but there are certain requirements for concentration at different times. The table of hCG norms by weeks of pregnancy will help to correctly interpret the test results.
But when studying the given data, it should be remembered that different laboratories use their own test systems, in which the sensitivity and units of measurement may differ. Therefore, only a doctor can reliably determine whether specific results correspond to the norm.
The origin and function of the hormone
After fertilization, the egg begins to produce a new type of hormone for the body. On the sixth to eighth day, the embryonic tissue of the syncytiotrophoblast takes over this function. HCG is structurally similar to gonadotropic hormones - luteinizing (LH) and follicle-stimulating (FSH) - but differs in the structure of the beta subunit. Therefore, the effects of hCG are similar to LH - stimulation of the corpus luteum to produce progesterone. But human chorionic gonadotropin, in contrast to luteinizing hormone, is more stable: its action lasts up to 12 hours.
In the body of a non-pregnant woman and in men, the hormone is not produced. But during gestation it is impossible to do without it. HCG during pregnancy plays a leading role in the following processes.
- Corpus luteum. It normally regresses 14 days after ovulation. But with a high level of hCG, the function of the corpus luteum does not weaken, but increases manifold until the placenta is formed.
- The ovaries. It has a weak stimulating effect on the follicular apparatus, which leads to the production of estrogens and androgens.
- Adrenal glands. It causes temporary moderate hyperplasia of the adrenal cortex, increases the production of glucocorticoids. They provide protection for a woman from stress and also induce the immunosuppression needed to carry a baby.
- Placenta Supports its function, helps to increase its nutrition and enhance the growth of chorionic villi.
- Fruit testes. Stimulates the testosterone cells of the male baby to produce testosterone and maintains this function until the very birth. Under the influence of the male hormone, by the time of childbirth, the testicles descend into the scrotum.
HCG rates by days and weeks of pregnancy (tables)
HCG begins to be produced after the fusion of the egg and sperm. But a blood test will show its concentration not earlier than on the sixth day after fertilization, and sometimes only on the ninth. At the same time, the growth of the hormone is fast. If the embryo develops correctly, in the early stages, hCG doubles every two days. The maximum concentration is determined by 11 weeks of gestation, and then there is a slight decrease in indicators. If, three months before the end of pregnancy, the number again becomes increased, then this is an unfavorable symptom, which may be an indicator of the Rh-conflict between the mother and the fetus.
The indications for prescribing an analysis for hCG during pregnancy are as follows:
- establishing the fact of early pregnancy;
- exclusion of ectopic pregnancy;
- risk of miscarriage;
- undeveloped pregnancy;
- diagnosis of fetal malformations;
- after an induced abortion.
This hormone helps to identify tumors: cystic drift, chorionepithelioma.
Dynamics of changes
Below is a table that reflects the normal values \u200b\u200bof hCG by week. The dynamics of changes will tell you whether the pregnancy is going well.
Table - HCG by week of pregnancy (normal)
The study requires venous blood. Take it in the morning on an empty stomach. The night before, they refuse spicy and fatty foods. If a woman assumes pregnancy in this cycle, hCG can be donated even before the delay, two weeks after intercourse. If the test result is negative and the monthly period is delayed, the analysis is repeated a week later.
Research during artificial insemination
With IVF, the study is carried out two weeks after the embryo replanting. The analysis allows you to determine:
- whether the embryos have taken root;
- the presence of an ectopic pregnancy;
- death of the embryo;
- developmental defects.
But in the case of IVF, one study is not enough. An analysis of the dynamics of hCG is required, which is monitored for certain days. The indicators are evaluated according to a special table.
Table - hCG by day (norm)
If a woman bears several fetuses, then the hormone content will increase proportionally. For example, if you double, the hCG values \u200b\u200bgiven in the table will double.
Reasons for deviations in analyzes
The deviation of the values \u200b\u200bof the hormone hCG from the norm can occur both upward and downward. The reasons for the high concentration are as follows:
- chromosomal abnormalities in a child;
- fetal malformations;
- pregnancy with twins, triplets;
- gestational diabetes mellitus;
- trophoblastic tumors;
- taking hCG drugs.
Decreased hCG is observed in certain pathological conditions:
- threatening miscarriage;
- ectopic pregnancy;
- antenatal fetal death;
- frozen pregnancy;
- chromosomal pathologies.
With the development of severe gestosis, chorionic gonadotropin can increase significantly, but this does not happen earlier than 20 weeks of gestation.
Ectopic pregnancy
If a fertilized egg has attached outside the uterine cavity, the symptoms will be the same as in a normal early pregnancy:
- drowsiness;
- weakness;
- delayed menstruation;
- engorgement of the mammary glands.
With a delay, women use express tests, the action of which is based on the determination of chorionic gonadotropin in the urine. If its concentration in the blood is high enough, it begins to be excreted by the kidneys. But with an ectopic test, it may be weakly positive, which does not cancel the onset of pregnancy.
Sometimes the test stays negative and pregnancy symptoms escalate. Then ultrasound and a blood test for hCG come to the rescue. In the first two to three weeks, the ovum is not always found. Deciphering the analysis will show the discrepancy between the amount of the hormone and the estimated gestational age. Then additional symptoms may appear, indicating an ectopic attachment of the ovum:
- abdominal pain;
- bloody discharge from the genital tract;
- palpitations and weakness.
A low level of the hormone is associated with a dysfunction of the trophoblast: the embryo is attached to the cavity of the fallopian tube, where there are no conditions for sufficient blood supply and nutrition.
Fetal death
With the help of an express test in early pregnancy, hCG can be determined in the urine. The woman feels all the signs of a completed conception. But a dynamic examination by a doctor reveals a lag in the size of the uterus from the gestational age. An analysis with a frozen pregnancy will show a very low hCG. The dead embryo stops producing the hormone, but the concentration in the blood decreases gradually.
With antenatal fetal death, which occurs in the second or third trimesters, the hormone test is not used. Ultrasound and CTG in diagnosing this condition are more informative and take much less time.
Developmental anomalies
Before 12 weeks, women undergo mandatory prenatal screening. He must identify gross malformations that are indications for termination of pregnancy. Mandatory stages are ultrasound, as well as analysis for hCG and PAPP-A. Even with a normal result at 16-18 weeks, a triple test is recommended, which includes:
- estriol-A.
Deviation from normal indicators, according to doctors, occurs with the following severe hereditary pathologies:
- down syndrome;
- neural tube defects;
- patau syndrome;
- trisomy 18 (Edwards syndrome);
- turner syndrome.
The diagnosis is not made only on the basis of one analysis, but this is an indication for conducting invasive studies:
- amniocentesis;
- cordocentesis;
- chorionic villus sampling.
The risk of chromosomal abnormalities increases if a woman is over 35 and has not given birth before. The examination is also recommended for those who have children with developmental disabilities and have early miscarriages.
Trophoblastic tumors
Sometimes, instead of a full-fledged pregnancy, a cystic drift develops - in the place of the chorion, many growths are formed in the form of bubbles. Embryonic tissues may be missing or altered. At the same time, hCG exceeds the norm by two or more times.
Sometimes after an abortion or childbirth, a chorionic carcinoma tumor forms. With a high risk of pathology, the study is carried out 40 days after the termination of pregnancy or childbirth. Analysis rates can either remain high or even increase.
HCG - chorionic gonadotropin
The hCG hormone is produced by the chorionic cells (membranes of the embryo) after the embryo is implanted into the uterus. Based on a blood test for b-hCG, the doctor determines the presence of chorionic tissue in the body, which means that a woman is pregnant. The hCG blood test makes it possible to detect pregnancy early - already 6-10 days after fertilization, the hCG result will be positive.
The role of hCG in the first trimester of pregnancy is to stimulate the formation of hormones necessary for the development and maintenance of pregnancy, such as progesterone, estrogens (estradiol and free estriol). With the normal development of pregnancy, these hormones are subsequently produced by the placenta.
Chorionic gonadotropin is very important. In a male fetus, hCG stimulates the so-called Leydig cells, which synthesize testosterone. Testosterone in this case is simply necessary, as it promotes the formation of male genital organs, and also affects the adrenal cortex of the embryo. HCG is made up of two units - alpha and beta-hCG. The alpha component of hCG has a similar structure to the units of the hormones TSH, FSH and LH, and beta-hCG is unique. Therefore, in the diagnosis, laboratory analysis of b-hCG is of decisive importance.
Pregnancy can also be diagnosed using home pregnancy tests based on the analysis of HCG excreted in the urine. But the reliability of the hCG result obtained by the "home" method is much lower than the laboratory analysis of hCG blood, since the level of hCG required for diagnosis in the urine is reached a few days later than in the blood.
The most common cases when a doctor prescribes an analysis for hCG:
Among women:
Amenorrhea
Diagnostics, early pregnancy detection
Eliminating the possibility of an ectopic pregnancy
To assess the completeness of induced abortion
HCG is also rented for dynamic monitoring of pregnancy
With the threat of miscarriage and non-developing pregnancy
Diagnosis of tumors - chorionepithelioma, cystic drift
Along with AFP and free estriol - as prenatal diagnosis of fetal malformations
In men:
Diagnosis of testicular tumors.
In serum
HCG norm, honey / ml
Men and non-pregnant women< 5
HCG levels during pregnancy:
1 - 2 weeks 25 - 300
2 - 3 weeks 1500 - 5000
3 - 4 weeks 10,000 - 30,000
4 - 5 weeks 20,000 - 100,000
5 - 6 weeks 50,000 - 200,000
6 - 7 weeks 50,000 - 200,000
7 - 8 weeks 20,000 - 200,000
8 - 9 weeks 20,000 - 100,000
9 - 10 weeks 20,000 - 95,000
11 - 12 weeks 20,000 - 90,000
13 - 14 weeks 15000 - 60,000
15 - 25 weeks 10,000 - 35,000
26 - 37 weeks 10,000 - 60,000
Note!
The norms of hCG by week are given for the timing of pregnancy "from conception" (and not for the timing of the last menstruation).
The above figures are not a benchmark! Each laboratory can set its own hCG norms, including Fetal development by week. When assessing the results of the hCG norm by weeks of pregnancy, you need to rely only on the norms of the laboratory where you were tested for hCG!
HCG growth by day DPO (day after ovulation):
No. dpo - min [average] max
7 dpo - 2 10
8 dpo - 3 18
9 dpo - 5 21
10dpo - 8 26
11dpo - 11 45
12dpo - 17 65
13dpo - 22 105
14 to - 29 170
15dpo - 39 270
16dpo - 68 400
17dpo - 120 580
18dpo - 220 840
19dpo - 370 1300
20dpo - 520 2000
21dpo - 750 3100
22dpo - 1050 4900
23dpo - 1400 6200
24dpo - 1830 7800
25dpo - 2400 9800
26dpo - 4200 15600
27dpo - 5400 19500
28dpo - 7100 27300
29dpo - 8800 33000
30dpo - 10,500 40,000
31dpo - 11,500 60,000
32dpo - 12800 63000
33dpo - 14000 68000
34dpo - 15,500 70,000
35dpo - 17000 74000
36dpo - 19000 78000
37dpo - 20500 83000
38dpo - 22000 87000
39dpo - 23000 93000
40dpo - 25000 108000
41dpo - 26500 117000
42dpo - 28000 128000
HCG decoding
Normally, during pregnancy, the level of hCG gradually rises. During the 1st trimester of pregnancy, the level of b-hCG increases rapidly, doubling every 2-3 days. At 10-12 weeks of gestation, the highest hCG level in the blood is reached, then the hCG content begins to slowly decrease and remains constant during the second half of pregnancy.
An increase in beta-hCG during pregnancy can occur when:
multiple pregnancies (the hCG rate increases in proportion to the number of fetuses)
toxicosis, gestosis
maternal diabetes
fetal pathologies, Down syndrome, multiple developmental defects
incorrectly set gestational age
taking synthetic gestagens
An increase in hCG can be a sign of serious medical conditions in non-pregnant women and in men:
testicular tumors
tumor diseases of the gastrointestinal tract
neoplasms of the lungs, kidneys, uterus
cystic drift, recurrence of cystic drift
chorionic carcinoma
taking hCG drugs
analysis for hCG was done within 4-5 days after the abortion, etc.
Usually, hCG is increased if the hCG test was performed 4-5 days after the abortion or as a result of taking hCG drugs. A high hCG level after a mini-abortion indicates an ongoing pregnancy.
Low hCG in pregnant women may mean incorrect setting of the term for determining pregnancy or be a sign of serious violations:
ectopic pregnancy
undeveloped pregnancy
delayed fetal development
threat of spontaneous abortion (lowered hCG by more than 50%)
chronic placental insufficiency
true prolongation of pregnancy
fetal death (in the II-III trimester of pregnancy).
It happens that the results of the analysis of hCG show the absence of the hormone in the blood. This result may be if the hCG test was performed too early or with an ectopic pregnancy.
Whatever the result of the analysis for hormones during pregnancy does not work, remember that only a qualified doctor can give the correct decoding of hCG, determining which hCG is the norm for you in combination with the data obtained by other examination methods.
How to get a blood test for the hCG hormone
To perform a hCG test, blood is taken from a vein. It is recommended to donate blood for hCG in the morning and strictly on an empty stomach. If you are taking the hCG test at a different time, you should abstain from food for 4-6 hours. And you should tell your nurse or your doctor if you are taking any hormonal medications.
A laboratory test for determining pregnancy in the early stages is recommended not earlier than 3-5 days of delayed menstruation. The pregnancy blood test can be repeated 2-3 days later to verify the results.
To identify the pathology of the fetus in pregnant women, an analysis for hCG, chorionic gonadotropin, is submitted from 14 to.
However, in order for the diagnosis of possible fetal pathologies to be reliable, it is necessary to pass more than one blood test for hCG. Together with hCG, the following markers are deposited: AFP, hCG, E3 (alpha-fetoprotein, human chorionic gonadotropin, free estriol.
Among the list of tests that a woman should undergo during pregnancy or who is 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, we will consider it in more detail.
HCG, what is it?
HCG is a hormone that is protein in nature and consists of two fractions - alpha and beta. The beta fraction of the hormone is of clinical interest, since alpha is similar in structure to other female hormones. And beta is unique - this makes it easy to detect 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 until the placenta begins to work. This contributes to the preservation of pregnancy and bearing 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 by stimulating the adrenal glands to produce glucocorticoids, making the expectant mother more resistant to stress. Carrying a baby is stressful for the female body, especially in the early stages.
3. When the placenta has already formed (at 16 weeks), hCG provides adequate nutrition and development, preventing premature detachment.
4. In medicine, the introduction of the hormone by injection is practiced. It stimulates ovulation and promotes conception in women. Using such injections in men, it is possible to increase 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 sample from a vein. The test result 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 level of the hormone changes depending on the duration of pregnancy and know the average values \u200b\u200bin non-pregnant women (see table).
Important! Indicators of the norm may vary, depending on the laboratory that performed the analysis.
In girls and men, hCG values \u200b\u200bshould be 0-5 mU / ml. This amount is so insignificant that a test performed to determine hCG in urine does not respond to it and will show one strip.
From the first days of pregnancy, the level of hCG will rise. This happens until 11-12 weeks, when the highest hormone value is noted. Further, gonadotropin gradually decreases and in the last stages of pregnancy shows approximately the same value.
Increased hCG during pregnancy
With the onset of fertilization, the level of chorionic gonadotropin increases. This happens literally right after fertilization.
The quantitative composition of the hormone is growing steadily and reaches a maximum by 11 weeks, and then declines. In the second half of pregnancy, the indicators stabilize and change little.
Rapid tests sold in a pharmacy to determine pregnancy can change color when hCG is found in 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 woman in a position 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 within 7-10 days from the moment the egg and sperm meet. Obtaining the results of the analysis of hCG at such an early stage makes it possible to control the course of pregnancy almost from the very moment of fertilization.
Careful monitoring of the level of the most important pregnancy hormone will prevent pregnancy complications, including termination. This is true for women who have tried unsuccessfully to experience the joy of motherhood, as well as in late-bearing women 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 bearing two or three fruits.
- Diseases of the fetus at the chromosomal level (Down syndrome).
- A history of diabetes mellitus in a pregnant woman.
- Severe gestosis during pregnancy.
- The use of female hormones from the outside.
Lowering hCG during pregnancy
The level of gonadotropin can decrease in the following cases:
- With an atypical location of the ovum (tubal, or).
- If the fetus is lagging behind in its development.
- With a frozen pregnancy.
- In case of impaired blood circulation between the baby and the placenta or between the placenta and the uterus.
- If .
- When overdue.
Increased hCG in women and men
A blood test for the hCG hormone in a non-pregnant woman or in a man 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.
HCG analysis decoding, table
For a doctor, decoding the result of the hCG analysis carries a lot of information during pregnancy. By analyzing 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 pathologies of the course, an impending miscarriage, etc.
This will help to take measures to preserve the desired child and take actions aimed at preventing complications in the expectant mother and her baby.
Of course, the diagnosis is not made only by the level of this hormone. More research is needed. But it is the amount of the main hormone of motherhood that indicates a possible problem and directs the doctor in the right direction to identify this problem.
| Gestational age | Average 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 rates of results in each laboratory may vary slightly!
