Whether the blood is tested for hCG. When does an hCG test show pregnancy? Could the result be wrong? What to do in such a situation
Description
Determination method Linked immunosorbent assay.
Material under study Blood serum
Specific pregnancy hormone.
Glycoprotein is a dimer with a molecular weight of about 46 kDa, synthesized in the syncytiotrophoblast of the placenta. HCG consists 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 already on days 6 - 8 after conception makes it possible to diagnose pregnancy (the concentration of beta-hCG in the urine reaches the diagnostic level 1 - 2 days later than in the blood serum).
In the first trimester of pregnancy, hCG ensures the synthesis of progesterone and estrogens necessary to maintain pregnancy by the corpus luteum of the ovary. HCG acts on the corpus luteum like luteinizing hormone, that is, it supports its existence. This occurs until the fetus-placenta complex acquires the ability to independently form the necessary hormonal background. In a male fetus, hCG stimulates Leydig cells, which synthesize testosterone, which is necessary for the formation of male genital organs.
HCG synthesis is carried out by trophoblast cells after embryo implantation and continues throughout pregnancy. During normal pregnancy, between 2 and 5 weeks of pregnancy, the β-hCG content doubles every 1.5 days. The peak concentration of hCG occurs at 10 - 11 weeks of pregnancy, then its concentration begins to slowly decrease. During multiple pregnancies, the hCG content increases in proportion to the number of fetuses.
Reduced concentrations of hCG may indicate an ectopic pregnancy or threatened abortion. Determination of hCG content 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 developmental abnormalities.
In addition to pregnancy, hCG is used in laboratory diagnostics as a tumor marker for tumors of trophoblastic tissue and germinal cells of the ovaries and testes that secrete human chorionic gonadotropin.
Early diagnosis of pregnancy: determination of hCG levels
What is hCG?
HCG (human chorionic gonadotropin) is a special pregnancy hormone, which is an important indicator of the development of pregnancy and its abnormalities. Human chorionic gonadotropin is produced by the cells of the chorion (the membrane of the embryo) immediately after its attachment to the wall of the uterus. Based on a blood test for human chorionic gonadotropin, the doctor determines the presence of chorionic tissue in the body, and therefore the onset of pregnancy in a woman.
When can a test be performed to determine hCG levels?
Determining the level of human chorionic gonadotropin in the blood is the most reliable method for determining pregnancy in the early stages. Human chorionic gonadotropin appears in a woman’s body 5-6 days after fertilization. A common rapid pregnancy test, which every woman can use at home, is also based on the determination of human chorionic gonadotropin in the urine, but the required level of this hormone in the urine to diagnose pregnancy is achieved several 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 week 11, the hormone level gradually decreases.
An increase in the level of human chorionic gonadotropin during pregnancy can occur with:
multiple births;
toxicosis, gestosis;
maternal diabetes;
fetal pathologies, Down syndrome, multiple developmental defects;
incorrectly determined gestational age;
taking synthetic gestagens, etc.
Elevated values can also be seen within a week when tested after an abortion procedure. A high level of the hormone after a mini-abortion indicates a progressive pregnancy.
Low levels of human chorionic gonadotropin during pregnancy may indicate incorrect timing of pregnancy or be a sign of serious disorders, such as:
ectopic pregnancy;
non-developing pregnancy;
delay in fetal development;
threat of spontaneous abortion;
fetal death (in the II-III trimester of pregnancy).
Determining the level of human chorionic gonadotropin is part of a triple test study, the results of which can be used to judge the presence of certain abnormalities in fetal development, but an accurate diagnosis cannot be made. The study only allows us to identify women at risk. In this case, women will need to undergo serious additional examination.
What is the role of the hCG hormone in the human body?
In addition to establishing the fact of pregnancy, by quantifying the level of this hormone, one can judge the nature of the pregnancy and the presence of multiple pregnancies.
The most important task of human chorionic gonadotropin is to maintain the pregnancy itself. Under its control, the synthesis of the main pregnancy hormones occurs: 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 order a hCG test?
In addition to diagnosing early pregnancy, human chorionic gonadotropin is determined by:
among women -
to detect amenorrhea;
eliminating the possibility of ectopic pregnancy;
to assess the completeness of induced abortion;
for dynamic monitoring of pregnancy;
if there is a threat of miscarriage and suspicion of an undeveloped pregnancy;
for the diagnosis of tumors - chorionepithelioma, hydatidiform mole;
for prenatal diagnosis of fetal malformations;
for men -
for the diagnosis of testicular tumors.
How to take a blood test for the hCG hormone?
The independent laboratory INVITRO offers a laboratory test to determine the level of human chorionic gonadotropin.
The test is taken 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 missed 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 the test from 14 to 18 weeks of pregnancy.
In a comprehensive diagnosis of fetal malformations, it is also recommended to take tests to determine the following markers: AFP (alpha-fetoprotein), E3 (free estriol), and also do an ultrasound.
Limits of determination: 1.2 mU/ml-1125000 mU/ml
Preparation
It is preferable to take blood in the morning on an empty stomach, after 8-14 hours of overnight fasting (you can drink water), it is acceptable during the day 4 hours after a light meal.
On the eve of the study, it is necessary to exclude increased psycho-emotional and physical stress (sports training), alcohol intake, and smoking an hour before the study.
The sensitivity of the method in most cases makes it possible to diagnose pregnancy already on the first or second day of delayed menstruation, but, due to individual differences in the rate of β-hCG synthesis in women, it is better to conduct the study no earlier than 3-5 days of delayed 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 removal of an ectopic pregnancy or abortion, a β-hCG test is carried out 1-2 days after surgery to exclude a false-positive result.
Interpretation of results
Interpretation of research 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. The doctor makes an accurate diagnosis using both the results of this examination and the necessary information from other sources: medical history, results of other examinations, etc.
Units of measurement in the INVITRO laboratory: honey/ml.
Alternative units of measurement: U/l.
Unit conversion: U/l = mU/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 confirm or refute pregnancy and require re-examination after 2 days.
Increased hCG levels
Men and non-pregnant women:
- chorionic carcinoma, recurrence of chorionic carcinoma;
- hydatidiform mole, relapse of hydatidiform mole;
- seminoma;
- testicular teratoma;
- neoplasms of the gastrointestinal tract (including colorectal cancer);
- neoplasms of the lungs, kidneys, uterus, etc.;
- the study was carried out 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 actual and established gestational age;
- early toxicosis of pregnant women, gestosis;
- maternal diabetes;
- chromosomal pathology of the fetus (most often with Down syndrome, multiple fetal malformations, etc.);
- taking synthetic gestagens.
Decrease in hCG levels
Pregnant women. Alarming changes in level: discrepancy with the gestational age, extremely slow increase or no increase in concentration, progressive decrease in level, more than 50% of the norm:
- ectopic pregnancy;
- non-developing pregnancy;
- threat of interruption (hormone levels decrease progressively by more than 50% of normal);
- chronic placental insufficiency;
- true post-term pregnancy;
- antenatal fetal death (in the II - III trimesters).
False negative results (non-detection of hCG during pregnancy):
- the test was carried out 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 a normal and altered structure, which is not always detected by the test system. Test results should be interpreted with caution and cannot be taken as absolute evidence of the presence or absence of disease when compared with clinical findings and other examination results.
Ectopic pregnancy is a condition when the fertilized egg attaches and grows not in the uterus, but in another place: in the fallopian tubes, in the ovaries, on the cervix.
Many women are afraid of ectopic pregnancy. Unfortunately, modern medicine does not have methods that allow the fertilized egg to be transferred to the uterus, where it will have an optimal environment for further growth. This pathology does not allow giving birth to a child, and can have dire consequences for the health and life of the mother.
At first, the symptoms of an ectopic pregnancy are difficult to identify. A woman feels the same as during a natural pregnancy. She has a delay in her periods, her breasts become engorged, and toxicosis may appear. A pharmacy pregnancy test will also be positive.
To detect an ectopic pregnancy, you need to go through several specialists, do an ultrasound, and test for the hCG hormone. The amount of this substance in the presence of pathologies differs markedly from the figures during normal pregnancy. If the fact of pregnancy outside the uterus is confirmed, there is only one way out - minimally invasive surgery.
This pathology poses a great danger to women's health. The main threat is a pipe rupture, which can happen around the fourth week. It is at this time that the embryo grows to such a size that it stretches the tube, which collapses under pressure. Rupture of the fallopian tube is a rather dangerous phenomenon, which is fraught not only with infertility, but also with a more serious situation. To prevent this, you should not neglect timely diagnosis.
The amount of hCG hormone can tell a lot about the course of pregnancy. If it is ectopic, the test results will be significantly lower than normal. A comprehensive examination to determine this condition includes a blood test to determine the amount of the hormone.
What is hCG
HCG stands for human chorionic gonadotropin. It is secreted by the membrane cells of the fertilized egg after it attaches to the wall of the uterus. First of all, the substance enters the mother’s blood and then spreads throughout the body.
There are several methods for measuring the level of this substance:
- blood test, it allows you to get the most accurate results;
- Analysis of urine;
- pregnancy test.
After the fertilized egg attaches to the uterine cavity, its membrane begins to actively produce the hormone hCG. This allows the egg to survive in an aggressive environment and ensures continuous development and growth of the embryo. This is a very important substance for the full development of the embryo until the connection between it and the mother’s body through the placenta develops.
HCG changes the hormonal background of a woman, rearranging all processes in the body to support the optimal background for the favorable growth and development of the child. It also suppresses the body's defenses so that new life is not perceived as a foreign body, and the immune system does not begin to fight it.
Hormone levels in the blood
The highest concentration of this substance is found in the blood and urine of the mother. It is worth noting that its amount in the blood is always greater, so in a blood test the amount of the hormone will be greater than in the urine. It is these liquids that are taken for research.
Any gynecologist has a table of hormone levels in the female body by week. However, there are no exact values; the norms are quite vague, since each organism is unique. Only a doctor can determine the presence of pathology.
The hormone is produced even in the presence of pregnancy outside the uterus. The existence of various pathologies may be indicated by a deviation in the amount of the hormone from normal levels. During ectopic pregnancy, a small concentration of it is observed in the mother's body.
The hormone allows you to detect many pathologies:
- ectopic pregnancy;
- frozen fruit;
- threat of miscarriage, others.
The results of the analysis can confirm or refute the presence of deviations.
HCG test at home
A regular pharmacy pregnancy test also allows you to determine the presence of the hCG hormone in the urine, showing two stripes. It is an indicator that responds to an increase in the substance in the urine. However, in this way it is impossible to accurately determine the presence of pathology. A poorly colored second strip indicates that the concentration of this substance in the urine is low. However, a similar result can occur in the early stages of a normal pregnancy.
The hCG test may also give a result in the form of two too bright stripes. This result can be observed in late pregnancy, as well as in certain liver diseases. To get a 100% result, you need to conduct a blood test to determine the level of the hormone in the laboratory.
Blood test for hCG
Using this analysis, you can accurately determine the presence of pregnancy before your period is missed. The analysis will show this five days after ovulation. If fertilization takes place, the hormone will be above 5 mU/ml.
A blood test allows you to get the most accurate result. It is recommended to donate blood in the morning on an empty stomach. If this is not possible, it is better to take the test five hours after eating.
The hormone level is assessed from the first day of conception using a special table. Deviations of the hormone level from the norm are a signal of the development of pathological processes. Both increased and decreased indicators are considered pathology.
A blood test is more likely to detect an ectopic pregnancy. Evidence of this may be a reduced level of this substance. Attention should be paid not only to the results in numbers, but also to the dynamics of hormone growth. It is also worth conducting an ultrasound of the uterine cavity and fallopian tubes.
In the first trimester of pregnancy, the hormone grows very quickly. Its concentration almost doubles every day. It reaches its peak at 7-19 weeks, after which the production of this substance gradually decreases, stopping at a certain level by 20-30 weeks.
Table of hCG hormone levels by week of pregnancy (normal):
- 1-2 weeks - within 24-155 honey/ml;
- 2-3 weeks – within 105-4875 mU/ml;
- 3-4 weeks – within 1110-31505 mU/ml;
- 4-5 weeks – within 2565-82305 mU/ml;
- 5-6 weeks – within 23105-151005 mU/ml;
- 6-7 weeks – within 27305-233005 mU/ml;
- 7-11 weeks – within 20905-291005 mU/ml;
- 11-16 weeks – within 6145-103005 mU/ml;
- 16-21 weeks – within 4720-80105 mU/ml;
- 21-39 weeks – within the range of 2705-78105 mU/ml.
The dates of data in the table are indicated from the moment of conception, and not from the last for menstruation or delay. The data indicated in the list should not be taken as a standard. They may vary depending on laboratory results. Only a doctor can confirm the presence or absence of pathology.
Hormone levels during ectopic pregnancy
Ectopic conception is a blow to a woman’s physical and psychological health, especially if the pregnancy is long-awaited. No doctor can say for sure what the cause of this pathology is.
The most reliable method to identify such pathology is ultrasound. You can determine the tubal fixation of the embryo by taking an hCG test. What indicators of this substance are observed when the fertilized egg is fixed outside the uterus?
If there is pathology, the hormone level will be different. In such a situation, as mentioned above, its concentration decreases sharply. Deviations can range from 20-50% of the norm.
At the initial stage of pregnancy, the amount of hCG may be normal, but then its increase sharply decreases. For example, if on an ultrasound the egg is not detected in the uterine cavity, and the hormone levels are at the level of 1000 mU/ml, then this may be evidence of an ectopic pregnancy.
If the hormone amount is less than the required value, then after two days the analysis must be repeated.
If the increase in the hormone is less than 1.6 times, and neither an increase nor a decrease is observed, then this may be evidence that the woman has an ectopic pregnancy. With this pathology, the substance doubles approximately once a week, and during normal pregnancy - every two days.
The following symptoms may also be evidence of an ectopic pregnancy::
- severe pain in the lower abdomen;
- prolonged uterine bleeding, both heavy and scanty;
- decreased blood pressure;
- fainting.
If such symptoms appear, you should immediately contact a medical facility, since a long-term ectopic pregnancy is fraught with dire consequences.
It is worth remembering that the hCG hormone is an important substance for a favorable pregnancy, so you should not neglect the doctor’s referral for testing.
When else can hormone levels be reduced?
- If hormone levels are underestimated, this may also indicate the presence of pathologies and problems with bearing a fetus.
- The absence of dynamics in the increase in the hormone is evidence that the fetus has stopped growing or has frozen.
- An insufficient amount of the hormone may indicate a threat of miscarriage. The reason for this phenomenon in most situations lies in changes at the hormonal level.
If the fetus is placed in the fallopian tube, it is a life-threatening situation for the woman. If you contact a doctor too late, the embryo ruptures the tube, causing severe bleeding.
It is necessary to note the insidiousness of this situation. In the early stages, distinguishing a natural pregnancy from an ectopic one is quite problematic. The final diagnosis can only be made by a specialist based on ultrasound and a set of tests.
What to do in such a situation?
Outside the uterus, the fetus cannot survive. This situation is dangerous for the health and life of the mother. If there is a pregnancy outside the uterine cavity, a surgical intervention is performed, as a result of which the fallopian tube is cut and the embryo is removed. In the later stages of visiting a doctor, you will have to completely remove the fallopian tube. In any case, she will no longer be able to fully perform her functions.
In the case where the embryo has attached to the cervix, curettage is performed. After this procedure, the woman becomes infertile. If the fertilized egg is attached to the ovary, it is removed along with the embryo.
By monitoring the amount of the hormone, doctors can provide the woman with the necessary medical care in a timely manner. A timely detected pregnancy outside the uterus allows you to take the necessary measures in a timely manner, thereby saving the health and even the life of the woman.
Knowing hCG levels is very important. This makes it possible to suspect abnormalities in time, in particular, to identify the unnatural location of a fertilized egg, and the faster the pathology is identified, the less danger to the woman’s health.
Video - Ectopic pregnancy. Signs, symptoms, timing and treatment methods
Video - What is hCG or human chorionic gonadotropin
Human chorionic gonadotropin (hCG) is a hormone that begins to be produced in a woman’s body during pregnancy. First, it is produced by the tissues of the embryo, and then by the placenta. The concentration of hCG in the urine gradually increases. This hormone is important for both the woman and the fetus.
The role of the hormone in the female body
The presence of hCG in the body is natural for a non-pregnant woman, but its concentration is negligible. Normally it contains 0–5 mU/ml. Active release of the hormone begins immediately after the zygote enters the uterine cavity. This happens 5–7 days after conception. The maximum concentration is reached at 9–10 weeks of pregnancy. The hormone is involved in:
- Activation of the production of progesterone by the corpus luteum, an important hormone in the body of a pregnant woman. The corpus luteum performs this function until the 13th week, and after that the placenta is formed and this function is assigned to it. Without progesterone, it becomes impossible for a fertilized egg to attach to the wall of the uterus. The hormone also prepares the uterus itself for enlargement, making the walls of the organ elastic.
- Suspension of the process of follicle maturation. In the ovary they remain dormant throughout the entire gestation period.
- Stimulation of the development of interstitial cells in the male fetus. They are found around the convoluted seminiferous tubules in the testicular stroma and are responsible for the secretion of steroids during puberty.
- Preventing the mother's immune system from reacting to the baby's body. This is especially important in the presence of Rh conflict, when the Rh of the mother’s blood differs from the Rh of the child.
Gonadotropin is necessary for the normal course of pregnancy at all stages, as well as for maintaining the mother’s condition during this period. Increased or decreased content of hubbub is an indication for a complete examination of the woman and fetus.
What affects hormone levels?
HCG levels are individual for each individual case, but more often they are within the acceptable range. Sometimes a change in hormone concentration may not be related to pregnancy.
The level of gonadotropin in urine during the perinatal period may increase for the following reasons:
- multiple pregnancy - concentration increases in proportion to the number of embryos;
- the presence of an extra chromosome in the child’s DNA – Down syndrome;
- gestosis of varying degrees;
- fetal hypoxia;
- development of defects of internal organs in the baby;
- diabetes;
- taking hormonal medications containing gestagen.
It is also worth considering that, according to test data and ultrasound, the doctor may incorrectly determine the due date. In this case, increased gonadotropin is quite justified.
HCG can grow even in the absence of fertilization. The most common cause is the formation of tumors of the uterus and appendages. The presence of the hormone in the urine may also indicate the growth of neoplasms from embryonic tissue. There is an increase in the level of hCG while taking medications containing this particular hormone, as well as some time after an abortion or induced birth. Sometimes the cause is normal ovulation.
The concentration of hCG can not only rise, but also fall. This is an alarm bell and may indicate serious deviations. A decrease in hormone levels indicates:
- fetal death or intrauterine growth retardation;
- fetal growth outside the uterine cavity;
- threat of miscarriage;
- fetoplacental insufficiency;
- placental abruption;
- late death of a child.
All these factors must be taken into account. If a pregnancy test based on hCG levels shows a positive result even in the absence of sexual activity in a woman, you should immediately consult a doctor for advice.
Laboratory methods for determining the hormone in urine
Tests for hCG are carried out if monitoring the dynamics of intrauterine development of the fetus is required, as well as if a tumor of the reproductive organs is suspected. Urine is also examined for gonadotropin if there are signs of a frozen pregnancy, and ultrasound does not detect the baby’s heartbeat. Indications for analysis are also the absence of menstruation. In addition, it is used to understand how well the induced abortion was performed.
The main method of laboratory testing of urine for hCG is the detection of the hormone using a specialized reagent. Based on its concentration, the specialist determines the gestational age. If it is higher or lower than normal and does not correspond to the deadline according to ultrasound, the patient is prescribed an additional examination. This is done in order to find out the reason for the deviation. Blood from a vein on an empty stomach is taken for analysis.
Preparing for the test
In order for the results to be correct and correspond to the real clinical picture, it is necessary to prepare your body for the collection of biomaterial. Any violations in preparation may lead to a false result and repeated testing.
Women donating biomaterial are not allowed to:
- have sex the night before;
- physically exert yourself (hard work, playing sports, etc.);
- drink alcohol and drugs, and smoke.
The biomaterial is collected in the morning in a sterile container. Morning urine contains slightly higher levels of hormones, which increases the likelihood of detecting hCG even in the early stages of pregnancy.
Normal hormone levels
A sensitive hCG hormone test will confirm pregnancy 7–9 days after conception. If your period has not started and the test remains negative, you should repeat it in a few days. Every day after conception, the level of hCG in the urine doubles, and closer to the 14th week it begins to rise rapidly.
The normal level of hCG in urine by day from conception is presented in the table:
| HCG value in urine by days after fertilization | |||||||
|---|---|---|---|---|---|---|---|
| Day after conception | Min. value in honey/ml | Wed. value in honey/ml | Max. value in honey/ml | Day after conception | Min. value in honey/ml | Wed. value in honey/ml | Max. value in honey/ml |
| 7 DPO | 2 | 4 | 10 | 25 DPO | 2400 | 6150 | 9800 |
| 8 DPO | 3 | 7 | 18 | 26 DPO | 4200 | 8160 | 15600 |
| 9 DPO | 5 | 11 | 21 | 27 DPO | 5400 | 10200 | 19500 |
| 10 DPO | 8 | 18 | 26 | 28 DPO | 7100 | 11300 | 27300 |
| 11 DPO | 11 | 28 | 45 | 29 DPO | 8800 | 13600 | 33000 |
| 12 DPO | 17 | 45 | 65 | 30 DPO | 10500 | 16500 | 40000 |
| 13 DPO | 22 | 73 | 105 | 31 DPO | 11500 | 19500 | 60000 |
| 14 DPO | 29 | 105 | 170 | 32 DPO | 12800 | 22600 | 63000 |
| 15 DPO | 39 | 160 | 270 | 33 DPO | 14000 | 24000 | 68000 |
| 16 DPO | 68 | 260 | 400 | 34 DPO | 15500 | 27200 | 7000 |
| 17 DPO | 120 | 410 | 580 | 35 DPO | 17000 | 31000 | 74000 |
| 18 DPO | 220 | 650 | 840 | 36 DPO | 19000 | 36000 | 78000 |
| 19 DPO | 370 | 980 | 1300 | 37 DPO | 20500 | 39500 | 83000 |
| 20 DPO | 520 | 1380 | 2000 | 38 DPO | 22000 | 45000 | 87000 |
| 21 DPO | 750 | 1960 | 3100 | 39 DPO | 23000 | 51000 | 93000 |
| 22 DPO | 1050 | 2680 | 4900 | 40 DPO | 25000 | 58000 | 108000 |
| 23 DPO | 1400 | 3550 | 6200 | 41 DPO | 26500 | 62000 | 117000 |
| 24 DPO | 1830 | 4650 | 7800 | 42 DPO | 28000 | 65000 | 128000 |
There are also hCG norms for each week of pregnancy. It is through them that the process of child development in the womb is controlled.
The average concentration of HCG in urine by week of pregnancy is presented in the table:
| Average hCG values in urine by week of pregnancy | |
|---|---|
| Week of pregnancy | HCG norm in honey/ml |
| 1–2 | 10-170 |
| 2-3 | 105-3100 |
| 3-4 | 1960-27300 |
| 4-5 | 11300-74000 |
| 5-6 | 31000–128000 |
| 6-7 | 27500–237000 |
| 7-11 | 21000–300000 |
| 11-16 | 15000–60000 |
| 16-21 | 10000–35000 |
| 21-38 | 10000–60000 |
In a non-pregnant woman, the amount of the hormone should be no more than 5 mU/ml. If the hCG content is higher than this value, it is necessary to re-test in a few days. Decoding the results will help you understand whether fertilization has occurred or not.
Tests for detecting hCG at home
It is not at all necessary to take tests to the laboratory to confirm or deny pregnancy. You can also do the test at home; pharmacy chains offer a wide range of tests for this purpose. They 
differ in sensitivity to the hormone, as well as in the method of use.
Sometimes it happens that the test is positive, but the laboratory test for hCG is negative. This happens due to poor quality of the test or problems in the child's development.
Types of Pregnancy Tests
The tests have one control strip, which becomes colored in any case. The second strip appears only if the hormone is present in the urine.
There are several types of tests:
- The test strip is the simplest option on the market. Due to its low cost and ease of use, it is the most popular. The strips are usually individually packaged, each with a control zone coated with a gonadotropin-sensitive reagent. The analysis takes only a few minutes. The strip is dipped into morning urine until a certain mark is reached and after 5 minutes the result is observed.
- Tablets have higher sensitivity and are much more expensive. Such rapid tests can detect pregnancy much earlier. The tablet itself consists of a plastic case and a hole with material impregnated with a reagent. Urine is applied into this hole using a pipette.
- Inkjet - easy to use and highly sensitive. To get the result, simply place the test rod under a stream of urine. Due to the high content of the reagent, it makes it possible to carry out it at very early stages.
- Systems with reservoirs - have a special container for collecting biomaterial. The only difference with previous tests is that they are convenient to use.
- Electronic tests of a new generation. Thanks to the latest technologies, they not only detect the hormone, but also determine its concentration. The test is equipped with a small electronic display that will show the gestational age. The only drawback is the high cost.
To ensure the accuracy of the test result, it is worth buying several options from different manufacturers. This will help you get an objective assessment. If after a negative test your period still does not begin, you should consult a gynecologist for advice.
The presence of the hormone in the urine is the first sign that a woman is pregnant. Based on the concentration of hCG, you can calculate the approximate day of conception even without an ultrasound. But the presence of a hormone does not always mean pregnancy, its appearance can be a consequence of many problems in the body, including malignant tumors. There is nothing complicated or confusing about performing the test at home. Due to its availability and the availability of different options, every woman can determine pregnancy using the hCG test.
HCG (human chorionic gonadotropin) or hCG (chorionic gonadotropin) is a special pregnancy hormone. HCG levels can be elevated not only during pregnancy and not only in women. Analysis for the level of free b-hCG is used in screening for intrauterine development and the presence of fetal pathologies in the first trimester of gestation. Please note that hCG standards for weeks of pregnancy, although they begin from the first week of embryonic development, however, at this period the results are practically no different from hCG levels in non-pregnant women.
The norms for hCG levels during pregnancy at different stages can be seen in the table below. But when assessing the results of the hCG norm by week of pregnancy, you need to rely only on the norms of the laboratory where you were tested for hCG!
HCG is human chorionic gonadotropin, a hormone that is actively produced by the cells of the chorion (fetal membrane) immediately after it attaches to the wall of the uterus. The “production” of this hormone is vital for preserving and maintaining pregnancy! It is hCG that controls the production of the main pregnancy hormones - estrogen and progesterone. If there is a serious deficiency of hCG, the fertilized egg detaches from the uterus, and menstruation occurs again - in other words, a spontaneous miscarriage occurs. Normally, the concentration of hCG in the blood of the expectant mother is constantly growing, reaching a maximum at 10-11 weeks of pregnancy, then the concentration of hCG gradually decreases to remain unchanged until birth.
What are the hCG levels for a normal pregnancy, and what is the hCG level for an ectopic pregnancy? Pregnant women receive special tables in laboratories that show what the hCG level should be at different stages of pregnancy.
When deciphering the resulting analysis for hCG, follow the following rules:
- Most laboratories report gestational age “from conception” rather than from the date of the last menstrual period.
- When evaluating your test results, always check the standards of the laboratory that performed your analysis. Since different laboratories may have different norms for hCG levels during pregnancy
- If your hCG level differs from the laboratory norm, do not panic! It is best to decipher the analyzes over time. Retake the test after 3-4 days and only then draw conclusions.
- If you suspect an ectopic pregnancy, be sure to undergo an ultrasound to make an accurate diagnosis.
NORMAL HCG IN THE BLOOD OF WOMEN DURING PREGNANCY
HCG levels during pregnancy honey/ml (INVITRO laboratory standards)
HCG values ranging from 5 to 25 mU/ml do not confirm or refute pregnancy and require re-testing after 2 days.
An increase in hCG levels can first be detected using a blood test approximately 11 days after conception and 12-14 days after conception using a urine test. Since the content of the hormone in the blood is several times higher than in the urine, a blood test is therefore much more reliable. During normal pregnancy, in 85% of cases, beta-hCG levels double every 48-72 hours. As pregnancy progresses, the time it takes for it to double can increase to 96 hours. HCG levels peak in the first 8-11 weeks of pregnancy, and then begins to decline and stabilizes during the remaining period.
HCG norms during pregnancy
Human chorionic gonadotropin hormone is measured in milli-international units per milliliter (mIU/ml).
An hCG level of less than 5 mIU/ml indicates the absence of pregnancy, and a value above 25 mIU/ml is considered confirmation of pregnancy.
Once the level reaches 1000-2000 mIU/ml, a transvaginal ultrasound should show at least a fetal sac. Because normal hCG levels can vary significantly between women during pregnancy and the date of conception may be miscalculated, diagnosis should not be based on ultrasound findings until the hormone level reaches at least 2000 mIU/ml. The result of a single hCG test is not enough for most diagnoses. To determine a healthy pregnancy, multiple measurements of human chorionic gonadotropin are required a couple of days apart.
It is worth noting that these figures should not be used to determine gestational age, as these figures can vary greatly.
There are two types of routine hCG blood tests available today. A qualitative test determines the presence of hCG in the blood. The quantitative hCG test (or beta-hCG, b-hCG) measures exactly how much of the hormone is present in the blood.
HCG levels by week
HCG levels by week from the start of the last menstrual cycle*
3 weeks: 5 - 50 mIU/ml
4 weeks: 5 - 426 mIU/ml
5 weeks: 18 - 7340 mIU/ml
6 weeks: 1080 - 56500 mIU/ml
7-8 weeks: 7650 - 229000 mIU/ml
9-12 weeks: 25700 - 288000 mIU/ml
13-16 weeks: 13300 - 254000 mIU/ml
17-24 weeks: 4060 - 165400 mIU/ml
25-40 weeks: 3640 - 117000 mIU/ml
Non-pregnant women:<5 мМЕ/мл
After menopause:<9,5 мМЕ/мл
* These numbers are just a guide - the level of hCG can increase differently for each woman over the weeks. It’s not so much the numbers that are important, but the trend in level changes.
Is your pregnancy progressing normally according to hCG?
To determine whether your pregnancy is progressing normally, you can use hCG calculator below on this page
By entering two hCG values and the number of days that have passed between tests, you will find out how long it takes for your beta-hCG to double. If the value corresponds to the normal speed at your stage of pregnancy, then everything is going well, but if not, you should be wary and conduct additional checks on the condition of the fetus.
Calculator for calculating the doubling rate of hCG
At the beginning of pregnancy (first 4 weeks), the hCG value doubles approximately every two days. During this time, beta hCG usually manages to rise to 1200 mIU/ml. By weeks 6-7, the doubling rate slows to approximately 72-96 hours. When beta hCG rises to 6000 mIU/ml, its growth slows down even more. The maximum is usually reached in the tenth week of pregnancy. On average, this is about 60,000 mIU/ml. Over the next 10 weeks of pregnancy, hCG decreases by approximately 4 times (to 15,000 mIU/ml) and remains at this value until delivery. 4-6 weeks after birth the level will be less than 5 mIU/ml.
Increased hCG levels
Men and non-pregnant women:
- chorionic carcinoma, recurrence of chorionic carcinoma;
- hydatidiform mole, relapse of hydatidiform mole;
- seminoma;
- testicular teratoma;
- neoplasms of the gastrointestinal tract (including colorectal cancer);
- neoplasms of the lungs, kidneys, uterus, etc.;
- the study was carried out 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 actual and established gestational age;
- early toxicosis of pregnant women, gestosis;
- maternal diabetes;
- chromosomal pathology of the fetus (most often with Down syndrome, multiple fetal malformations, etc.);
- taking synthetic gestagens.
Decrease in hCG levels
Pregnant women. Alarming changes in level: discrepancy with the gestational age, extremely slow increase or no increase in concentration, progressive decrease in level, more than 50% of the norm:
- ectopic pregnancy;
- non-developing pregnancy;
- threat of interruption (hormone levels decrease progressively by more than 50% of normal);
- true post-term pregnancy;
- antenatal fetal death (in the II - III trimesters).
False negative results (non-detection of hCG during pregnancy):
- the test was carried out 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 a normal and altered structure, which is not always detected by the test system. Test results should be interpreted with caution and cannot be taken as absolute evidence of the presence or absence of disease when compared with clinical findings and other examination results.
Level HCG for ectopic pregnancy will be significantly lower than the specified standards and this will allow you to react to the current situation in a timely manner.
Analysis for the level of free b-hCG is used in screening for intrauterine development and the presence of fetal pathologies in the first trimester of gestation. This test is performed between 11 and 14 weeks of embryonic development. Its purpose is to identify possible pathological changes in development in the form of trisomy 18 or 13 pairs of chromosomes. In this way, you can find out the child’s tendency to illnesses such as Down’s disease, Patau and Edwards syndromes.
This test is carried out not to determine the fetus’s predisposition to the above ailments, but with the aim of excluding them, therefore no special indications for the test are required. It is as routine as an ultrasound at 12 weeks.
Increased hCG levels during pregnancy may occur when:
- multiple births;
- toxicosis, gestosis;
- maternal diabetes;
- fetal pathologies, Down syndrome, multiple developmental defects;
- incorrectly determined gestational age;
- taking synthetic gestagens, etc.
Elevated values can also be seen within a week when tested after an abortion procedure. A high level of the hormone after a mini-abortion indicates a progressive pregnancy.
Low hCG levels during pregnancy may indicate incorrect timing of pregnancy or be a sign of serious disorders, such as:
- ectopic pregnancy;
- non-developing pregnancy;
- delay in fetal development;
- threat of spontaneous abortion;
- chronic placental insufficiency;
- fetal death (in the II-III trimester of pregnancy).
Rules for preparing for a blood test for hCG during pregnancy
- Blood donation should take place in the morning (from 8 to 10 pm). Before taking the test, it is better not to eat fatty foods and not to have breakfast in the morning.
- The day before blood sampling, it is strictly forbidden to drink alcohol, take medications, or engage in physical activity.
- A couple of hours before the test, do not smoke, do not drink anything other than plain water; eliminate stress and emotional instability. It is better to rest and calm down before the test.
- It is not recommended to donate blood after physical procedures, examinations, massage, ultrasound and x-rays.
- If it is necessary to retake the test in order to monitor indicators, it is recommended not to change the conditions for donating blood (time of day, meals).
HCG test during pregnancy - meaning
Firstly, an analysis of the level of hCG in the blood can confirm that you will become a mother already 5-6 days after conception. This is much earlier and, most importantly, much more reliable than using conventional rapid tests.
Secondly, the test is necessary to determine the exact duration of pregnancy. Very often, the expectant mother cannot name the exact date of conception or gives it, but incorrectly. At the same time, each period corresponds to certain indicators of growth and development; deviations from the norm may indicate the occurrence of complications.
Thirdly, the level of hCG in the blood can quite accurately “tell” whether your baby is developing correctly.
An unscheduled increase in hCG levels usually occurs with multiple pregnancy, gestosis, taking synthetic gestagens, diabetes mellitus in the expectant mother, and can also indicate some hereditary diseases in the baby (for example, Down syndrome) and multiple developmental defects. An abnormally low level of hCG can be a sign of an ectopic and non-developing pregnancy, delayed fetal development, threatened spontaneous abortion, and chronic placental insufficiency.
However, do not rush to sound the alarm: increased or decreased values may also indicate that the gestational age was initially set incorrectly. Your doctor will help you interpret test results correctly.
Chemical structure of hCG and its role in the body
Glycoprotein is a dimer with a molecular weight of about 46 kDa, synthesized in the syncytiotrophoblast of the placenta. HCG consists 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 already on days 6 - 8 after conception makes it possible to diagnose pregnancy (the concentration of beta-hCG in the urine reaches the diagnostic level 1 - 2 days later than in the blood serum).
In the first trimester of pregnancy, hCG ensures the synthesis of progesterone and estrogens necessary to maintain pregnancy by the corpus luteum of the ovary. HCG acts on the corpus luteum like luteinizing hormone, that is, it supports its existence. This occurs until the fetus-placenta complex acquires the ability to independently form the necessary hormonal background. In a male fetus, hCG stimulates Leydig cells, which synthesize testosterone, which is necessary for the formation of male genital organs.
HCG synthesis is carried out by trophoblast cells after embryo implantation and continues throughout pregnancy. During normal pregnancy, between 2 and 5 weeks of pregnancy, the β-hCG content doubles every 1.5 days. The peak concentration of hCG occurs at 10 - 11 weeks of pregnancy, then its concentration begins to slowly decrease. During multiple pregnancies, the hCG content increases in proportion to the number of fetuses.
Reduced concentrations of hCG may indicate an ectopic pregnancy or threatened abortion. Determination of hCG content 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 developmental abnormalities.
In addition to pregnancy, hCG is used in laboratory diagnostics as a tumor marker for tumors of trophoblastic tissue and germinal cells of the ovaries and testes that secrete human chorionic gonadotropin.
Save on social networks:One of the most used and widely known methods for the 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 test 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 of implantation of the fertilized egg 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 figure doubles every 2 days. From the 12th to the 16th week, the concentration of the hormone gradually decreases, from 16 to 34 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 - estrogen 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. Therefore, hCG tests in blood and urine are 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), as well as (in postmenopausal women) special cells of the pituitary gland.
HCG difference in blood and urine
Immediately after the start of hCG synthesis by the membranes of the embryo, the hormone enters the woman’s blood, where it realizes its physiological effects. Therefore, hCG appears in the blood of a pregnant woman already on the day of egg implantation - that is, 7-8 days from conception. Moreover, for the hormone to appear in the urine, it is necessary that the level of hCG in the blood reach 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
The hCG blood test 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 operating procedures of a particular laboratory).
How to donate blood for hCG correctly
To obtain the most reliable test results, it is very important to know how to properly donate blood for hCG. The concept of “donating correctly” in this case implies the timing of blood donation, specific preparation for the test and the choice of place for collecting blood for hCG analysis.
When can you 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 questionable. Therefore, it is best to donate blood after 1-2 days of missed menstruation.
In some cases (when donating blood before a missed period, to exclude a frozen or ectopic pregnancy), the doctor prescribes a triple test, that is, blood for hCG in this case must be donated 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 indicate that problems with pregnancy are possible.
If a hCG blood test is performed to confirm the success of surgery for an ectopic pregnancy or medical abortion, blood for testing is taken 1-2 days after the surgery/abortion.
If blood for hCG is taken for other reasons (for example, to identify certain tumors or monitor the progress of pregnancy), the test can be taken on any day convenient for the patient.
Blood test for hCG during pregnancy
It should be said that blood for hCG during pregnancy is examined not only for early diagnosis of pregnancy. A very important test is the hCG blood test, 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 hCG test during pregnancy can be performed at any stage to monitor the progression of pregnancy.
On 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 as the mandatory screening ultrasound of the fetus in the 1st and 2nd trimesters.
When to donate blood for hCG before a delay
As mentioned above, hCG appears in a woman’s blood already 7-8 days after conception, that is, about a week before a missed period. However, during 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 donate blood for hCG for the first time before a missed period must repeat this test at least 2 more times with an interval of 2-3 days in order to get a reliable result.
Where is blood taken for hCG?
For hCG analysis, venous blood is used, which is obtained using standard methods. Typically, the vein of the elbow is used for this, that is, a vessel that runs shallow under the skin in the area of the inner bend of the elbow. If the veins in the elbow area are deep or have a structure that makes it difficult to draw blood, the technician can use veins in the hand or other superficial venous vessels.
Blood test for hCG on an empty stomach or not
Blood for hCG analysis is taken in a fasting state - 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 collecting the sample.
Blood test for hCG when it shows pregnancy
The most reliable result of a blood test for hCG to diagnose pregnancy can be obtained on the 3-5th day of a missed period and at a later date. 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.
HCG level in blood
When interpreting the results of a blood test for hCG, it is necessary to take into account the gender, age of the patient, indications for the test, as well as the units of measurement and normal limits used by the laboratory. Only compliance with all these conditions will allow you to obtain useful information from the result of a blood test for hCG, so a qualified doctor should decipher the test result.
Below are the normal values of hCG levels 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 test result. These figures are presented 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:
- 6-8 days - 5-50 mIU/ml;
- days 7-14 - 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 pregnancy exists and it is developing normally.
HCG in the blood by day
The following indicators are used to monitor the course of pregnancy and prenatal screening for fetal defects/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 |
| 12 -13th week | 27832,0-210612,0 |
| Week 14 | 13950,0-62530,0 |
| Week 15 | 12039,0-70971,0 |
| Week 16 | 9040,0-56451,0 |
| Week 17 | 8175,0-55868,0 |
| Week 18 | 8099,0-58176,0 |
Normal hCG level in blood
In the blood of non-pregnant women, the normal level of 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 frozen pregnancy;
- suspicion of a threat of termination of pregnancy;
- monitoring the development of pregnancy;
- suspicion of certain tumor diseases in men (testicular tumor) and women (chorionepithelioma, chorionic carcinoma);
- assessment of the outcome of surgery for ectopic pregnancy and medical abortion;
- diagnosis, effectiveness monitoring and follow-up after trophoblastic disease.
Blood test for hCG decoding
In men and non-pregnant women, only an increase in hCG levels has diagnostic value. Increase in hCG level above the upper limit of normal in this group of people may indicate:
- presence (relapse) of chorionic carcinoma or hydatidiform mole (women);
- presence of seminoma or testicular teratoma (men);
- the presence of a tumor of the gastrointestinal tract, lungs, kidneys, uterus.
In women, elevated levels of hCG can be detected within 4 to 5 days after an abortion, as well as while taking hCG drugs.
During pregnancy, both an increase and a decrease in hCG levels are important.
Increase in hCG level may indicate the presence of a multiple pregnancy; prolonged pregnancy; the presence of early gestosis or diabetes mellitus in the pregnant woman, the presence of Down syndrome or multiple malformations in the fetus. Also, an increase in the level of hCG in the blood of pregnant women (above the level normal for a given stage of pregnancy) is possible if the duration of pregnancy is incorrectly determined and while taking hormonal drugs to prevent miscarriage.
Decrease in hCG levels during pregnancy may be associated with the presence of an ectopic or frozen pregnancy, threatened miscarriage, placental insufficiency, post-term pregnancy and intrauterine fetal death.
