When to go donate blood for hcg. A blood test for hCG: when to donate and for how long the pregnancy will show. Reasons for increasing hCG levels

02.09.2020

To determine pregnancy, in addition to using the usual strip test, women resort to blood donation. An analysis for hCG, passed at a certain time, can diagnose pregnancy in a woman with maximum certainty. HCG or human chorionic gonadotropin is often referred to as the "pregnancy hormone". HCG is produced by a component of a fertilized egg or by certain germ cell tumors.

Human chorionic gonadotropin can be found in the blood or urine. The most accurate result can be obtained by donating blood. Test strips, which women often use to determine pregnancy, are also able to determine the presence of this hormone in the body. They are equipped with special reagents that change color when hCG is present in a woman's urine.

Functions of hCG in female body:

Regulates hormonal processes during pregnancy.
Stimulates the development of the placenta.
Responsible for the implantation of the egg to the wall of the uterus.
Contributes to the preservation of the corpus luteum.
Accelerates the production of progesterone and estrogen.
Stimulates the work of the gonads and adrenal glands in the fetus.
Prepares the mother's immunity for the adoption of the fetus.
Stimulates Leydig cells that produce testosterone in male embryos.

Advice:

HCG can be found not only in the female body, but also in the male.

In addition to the fact that this hormone can indicate the onset of pregnancy, it can also signal cancer.

An analysis for hCG is prescribed in the following cases:

To identify the reasons for the delay or absence of menstruation.
To determine a successful conception.
To determine the duration of pregnancy.
To detect an ectopic pregnancy.
To detect malformations of intrauterine development of the child.
For diagnosing diabetes.
For the diagnosis of oncology.

To date, there are two types of routine hCG blood tests:

A qualitative test determines the presence of hCG in the blood.
A quantitative hCG test (or beta-hCG, b-hCG) measures exactly how much of the hormone is present in the body.

How to take an analysis for hCG

In order to get the most reliable result, the analysis must be passed correctly. Testing blood for human chorionic gonadotropin is considered by doctors to be one of the most complex tests, so every little thing is important both in the blood donation procedure and in the study of biomaterial in the laboratory.

Blood for human chorionic gonadotropin is taken from the cubital vein in an amount of 5 ml.

It is necessary to take the analysis strictly on an empty stomach. It is best to do this in the morning before breakfast. If you come to the laboratory at lunchtime, then before the blood donation procedure, you should not eat for about 5-6 hours.
Two days before the procedure, fatty and fried foods, alcohol are excluded from the diet.
Smoking is prohibited 1 hour before blood sampling.
You must tell your doctor about all medications you take.
Before the procedure, physical activity, stressful situations, emotional overexcitation are excluded.

When to get tested for hCG

To determine pregnancy, you need to take an analysis for hCG on a certain day after the onset of ovulation. Fertilization, as a rule, occurs in the middle of the cycle (13-16 days). The path of a fertilized egg to the uterine cavity takes approximately 5-7 days. As soon as the egg is attached to the wall of the uterus, the active production of the hormone begins.

If the planned term of conception is known, you can take an analysis on the 8th - 10th day after the expected date of conception (sexual intercourse). If the day of conception is unknown, the analysis is taken on the 4th day after the first day of the delay in menstruation. The analysis is repeated after 2 days in the same laboratory to obtain a more accurate result.

When the fetus develops correctly, the woman compares the results with the table and observes how the hormone level rises day by day and week. In this case, she can make sure that everything is going well.

Level by week of pregnancy

Term in weeks	Average units mIU/ml	Limits of the norm mIU / ml
2	150	50-300
3-4	2000	1 500-5 000
4-5	20 000	10 000-30 000
5-6	50 000	20 000-100 000
6-7	100 000	50 000-200 000
7-8	80 000	40 000-200 000
8-9	70 000	35 000-150 000
9-10	65 000	32 000-130 000
10-11	60 000	30 000-120 000
11-12	55 000	27 000-110 000
13-14	50 000	25 000-100 000
15-16	40 000	20 000-70 000
17-20	30 000	15 000-55 000

Decryption of the received data:

How to understand that pregnancy is confirmed

The human chorionic gonadotropin hormone is measured in milli-international units per milliliter (mIU/mL). If in the analysis of a woman the level of hCG is less than 5 mIU / ml, this indicates that the conception did not take place. If the hormone level is above 25 mIU / ml, pregnancy is considered confirmed. When the hormone level reaches 1000-2000 mIU / ml, a transvaginal ultrasound should show at least a gestational sac. To determine a healthy pregnancy, doctors recommend multiple measurements of human chorionic gonadotropin with a difference of a couple of days (2-4 days).

What do different levels of hCG in the blood indicate?

Fluctuations in hCG in the blood up or down can indicate pregnancy and the condition of the fetus, the presence of tumor formations, etc. If we talk about the content of hCG in the blood during pregnancy, then at week 2 the content of the hormone in the blood can be either 100 or 300 mIU / ml. At week 3, the hormone is produced many times more, so its content can vary from 500 mIU / ml or more. By week 4, hCG gradually reaches 1600, 2500, 2800, 3000, 4000, 5000 mIU / ml. The growth of hCG continues until about 8 weeks, after which there is a slow decline.

If the hormone levels exceed the permissible norm or, conversely, below the norm, this is a good reason to consult a doctor. A decrease in the parameters of the chorionic hormone in women in the position on different periods gestation may indicate:

Ectopic pregnancy.
Anomalies in the development of the fetus.
Frozen pregnancy.
Fetoplacental insufficiency.
The threat of miscarriage.
Fetal death.

An increase in hormone levels in excess of the norm in the blood of a pregnant woman can occur due to:

The use of progestin preparations based on the steroid hormone - progesterone.
Multiple pregnancy or pregnancy over 42 weeks.
Erroneously set date of conception (if the period is set less than it actually is).
Error during analysis.
Diabetes mellitus in a woman.
Chromosomal abnormalities in the development of the embryo.
Severe toxicosis, which is accompanied by nephropathy and swelling.

Erroneous results:

False negative response

A false negative response is the result of an analysis in which hCG in the blood is not detected in the presence of pregnancy. This can happen for several reasons. The most common causes:

The analysis will be too early.
The analysis will be wrong.
Ectopic pregnancy.

The level of hCG during an ectopic pregnancy will be significantly lower than normal, which will allow the woman to respond in time to the current situation.

False positive response

If an analysis for hCG shows that a woman is in a position, but pregnancy does not occur, one should talk about the so-called false positive response. A woman may receive a false positive response due to:

Taking medications based on hCG for the treatment of infertility.
Failure in the body (the body produces an excessive amount of the hormone).
Tumor formations.
Choriocarcinomas.

Choriocarcinoma has a number of signs by which the disease can be recognized. In addition to the fact that hCG is found in the blood of a non-pregnant woman, she also has:

Vaginal bleeding.
Enlargement of the uterus.
Decidual reaction in the endometrium.

One of the main clinical studies to confirm the fact of conception on this stage is an analysis for hCG. When will the blood on hCG show that the pregnancy has come?

Before you figure out when hCG begins to be produced, it is worth saying a few words about what this analysis is. HCG is human chorionic gonadotropin, which is produced first by a fertilized egg, after which this “role” is taken over by the trophoblast.

It is for this reason that with an increase in the level of this hormone, in the absence of any pathologies in the body, we are talking about a developing pregnancy. In turn, an increase in the level of hCG without pregnancy may be due to a number of pathological conditions. You can read more about the rate of this hormone in the article.

Chorionic gonadotropin begins to be synthesized immediately after the attachment of the gestational egg to the wall of the uterus. This occurs approximately 4-6 days after conception. And already 7 days after the fertilization of the egg, this hormone appears in the blood of a woman. But sometimes the concentration of gonadotropin in the body is insignificant, so not all tests and clinical tests are able to recognize it.

After implantation of the embryo, a rapid increase in gonadotropin is observed. So, taking an analysis for this hormone according to the scheme once every 2 days, you can notice that the hCG indicators double. And so throughout the 1st trimester. After 12 weeks, the hormone levels will begin to gradually decrease, since now the placenta is responsible for the development of the embryo. It is through her that the fetus will now receive all the necessary nutrients that support its normal growth.

But this is in the case of a normal development of pregnancy. If there are any deviations, then the hormone levels may be higher or lower than normal. So, for example, with a low growth rate of gonadotropin, we can talk about a dying or ectopic pregnancy. Whereas high levels of this hormone may indicate abnormal fetal development. Therefore, it should be understood that the analysis of hCG is very important for diagnosing the condition of a pregnant woman, and it is highly not recommended to refuse to take it.

Methods for diagnosing hCG

So, we have already found out that a positive analysis, in the normal state of the woman's body, shows pregnancy. Now let's figure out what methods of diagnosing hCG are used in relation to pregnant women.

It’s worth saying right away that all home pregnancy tests work precisely by responding to the presence of this hormone in urine. The only thing is that express tests may not always show a reliable result, which may be due to the low sensitivity of the test or its “inoperative state”, provoked by the expiration of its expiration date.

In fact, the hormone can be determined in the blood and / or urine of a pregnant woman. At what gestational age the hCG test is able to show that conception has taken place, we have also already decided - in the blood, gonadotropin, using high-precision equipment, can be determined as early as 6-7 days after conception. Whereas doctors recommend taking the test no earlier than 1-2 days after the delay in menstruation.

HCG in the blood: growth dynamics

Outcome

Summarizing all of the above, let's summarize a little:

HCG is a chorionic hormone that is produced by the outer shell of the embryo in order to stimulate processes in the body of the expectant mother that support the vital activity of the fetus. Analysis for hCG helps to determine on early dates pregnancy, whether conception took place or not.
When can hCG in the blood show pregnancy? The synthesis of the hormone begins immediately after the implantation of the gestational egg to the wall of the uterus, which occurs on the 5-7th day after conception. Whereas in the blood, hCG will appear in sufficient quantities only 1-2 after implantation.
Gonadotropin is excreted by the kidneys, therefore, as soon as it is processed by the genitourinary system, it immediately enters the urine. And it is on the principle of reaction to this hormone that home tests work. It should be borne in mind that gonadotropin appears in the urine a little later, in contrast to its entry into the blood - somewhere in 10-14 days after conception.

Have you ever taken an hCG test to determine pregnancy? If so, at what stage was it and did the study show a reliable result?

One gram of prevention is better than one kilogram of cure. Learn how to test for the level of the hormone hCG on initial stage pregnancy will help you experience the joy of motherhood later on.

HCG result - expectation or reality?

The unknown is always scary, and when a pregnant girl who recently found out that she will soon become a mother is sent to be diagnosed for unknown markers, a number of questions arise.

The first trip to the gynecologist in order to register for pregnancy is often accompanied by the issuance of a whole list of referrals for various tests.

One of them is the detection of the level of hCG.

What is HCG

HCG (chorionic gonadotropin) is a hormone protein produced by a fertilized egg after it has entered the uterine cavity. It is involved in the regulation of the reproductive system and adrenal glands, ensures the proper development of the placenta, the production of estrogen and progesterone, and is important for a healthy pregnancy.

The hormone got its name from the chorion - the shell of the embryo from which the placenta appears, and gonadotropin - a hormone that affects the genitals of a woman. A study on chorionic gonadotropin is prescribed not only for pregnant women. HCG is also released in oncological diseases (in men and women). Therefore, the analysis is also done to check for the presence of cancer cells.

What level before pregnancy

In a healthy woman before pregnancy, the hCG result will be from 0 to 5 mU / ml.

When it begins to grow and be intensively produced

HCG forms chorion tissue already 8 days after ovulation, and it is actively produced from the first hours after fertilization (when the villi of the embryo are attached to the endometrium of the woman's uterus). HCG is finally converted by the kidneys and excreted from the body through the urine.

The amount of the hormone increases every 2-3 days by about 2 times (depending on the physiological characteristics of the mother). And this continues for 7-11 weeks. The highest figures will be at the end of the first trimester. After that, the level of the hormone should go down.

Due to this rate of production of the hCG hormone, two other hormones are actively formed in the body of a pregnant woman:

Estrogen. It is necessary for the full development of the fetus in the womb, maintaining the changes taking place in the woman's body, preparing it for childbirth and breastfeeding, and stabilizing work immune system, improving the functional abilities of the sex glands and adrenal glands.
Progesterone. It helps to maintain healthy conditions for the development and preservation of the fetus, relaxation of the muscles in the pelvis, preparation of the uterus for childbirth, incandescence of nutrients for the child, the development of testosterone (if the embryo is male).

When can I take it for pregnancy, from what week will it show

Urine tests will be able to detect the presence of the hormone as early as 9-14 days after fertilization. However, a blood test for hCG is more accurate and truthful.

If the growth dynamics does not correspond to the expected period

Not all women have pregnancy according to standard parameters and generally accepted indicators. Sometimes the level of hCG does not fit the norms of the current period - either too high or too low. Such women are required to be under strict medical supervision and undergo treatment appropriate to her health.

Can something affect the growth of hCG during pregnancy: risk factors

HCG is not an independent hormone. Various factors can influence its dynamics of education.

Reasons for the overestimation:

preeclampsia (edema, convulsions, high blood pressure);
diabetes;
multiple pregnancy;
tumors (most often in the reproductive system);
oncology of the respiratory system, stomach, intestines, kidneys;
delayed pregnancy;
taking synthetic gestagens - medicines that contribute to the production female hormone progesterone ("Dufaston" or "Utrozhestan");
early toxicosis;
wrong deadline;
chromosomal abnormalities of the embryo (Down's disease).

If Down's disease is suspected, the level of chorionic gonadotropin should be 2 times higher than normal, and ultrasound will not show the bone of the nose of the fetus. The diagnosis is finally stated in the first trimester at 11-14 weeks after additional tests have been carried out (2-3 days after the first one).

Underestimated indicators are when:

ectopic pregnancy (development of the embryo in the fallopian tube);
the threat of miscarriage (the level is below the norm by 2 times);
delayed or abnormal development of the embryo (Edwards disease or Patau syndrome);
fetal death in the 2nd or 3rd trimester;
delayed, frozen or non-developing pregnancy;
malfunctions in the development of the placenta;
inaccurate gestational age.

The final response of the examination is not affected by any medication and not a single contraceptive. An exception to the rule is drugs with the hCG hormone, which are used for infertility.

When can I donate blood for determination without a doctor's prescription?

HCG is found primarily in the blood and then in the urine.

Therefore, to confirm pregnancy most the best test there will be a blood test.

The examination can be carried out already on the 6-14th day after fertilization (most often on the 11th) or on the 4-7th day of the delay in the menstrual cycle. The answer will be ready from 2 to 24 hours.

How often is it prescribed to donate blood for human chorionic gonadotropin in the first trimester

The first analysis can be done at the first delay of the menstrual cycle. Then doctors recommend doing several examinations at 8-14 weeks to have a complete picture of how the pregnancy is proceeding.

To track the growth dynamics of hCG, the first three analyzes can be taken with an interval of three days, at the same time.

Indications for appointment

The analysis is assigned:

For routine monitoring of the condition of a pregnant woman.
If you suspect an ectopic conception.
During a comprehensive examination to identify pathologies in the fetus (at 16-20 weeks).

Can analysis be wrong?

Nothing is perfect. In carrying out the analysis, there is also a risk of getting a false result due to the wrong actions of a woman or medical staff. The result can be false positive and false negative.

Reasons for a false positive result (a woman is not pregnant, and the test shows the opposite):

Cancers of the breast, ovaries, stomach.
Hormonal disbalance.
Long-term use of hormonal drugs for infertility.

About 2% of women receive a false positive answer.

Reasons for a false negative result (a woman is pregnant, but the test does not reveal this):

Tested early.
Ectopic pregnancy.
Late fixation of the embryo in the endometrium of the uterus.
Death of a child in the womb.
Risk of miscarriage.
Problems in the development of the placenta.
Poor quality blood sampling by a laboratory assistant.

Is it possible to donate blood in the evening

You can, subject to certain conditions:

do not eat 6 hours before the analysis;
limit physical activity;
consult with your doctor about the use of hormonal medications on this day.

How to donate blood for hCG

Blood is taken from a vein, in the morning on an empty stomach on an empty stomach. For a day, you need to give up fried, fatty foods and physical activity, for 10 hours - give up any food. Inform the doctor about taking medications and, if necessary, cancel them at the time of the test.

Indicators of the growth of hCG levels during pregnancy: table

It is very important to do regular tests for the level of human chorionic gonadotropin in the blood to detect any abnormalities in the development of the child or health problems of the mother. The following table with approximate indicators will help determine whether the results obtained correspond to the generally accepted hCG norm by week.

Week (from conception)	Indicators, honey/ml	Notes
1	15-150	At these times, the level of hCG can increase in a couple of days immediately by 60%
2	50-156
3	100-4 850
4-5	2 500-85 300	The placenta is formed and the blood flow between it and the uterus, the uterus is rounded, the heart begins to beat
5-6	23 000-233 000
7	29 000-100 000	There is toxicosis, fatigue. The child already has a spinal cord and brain, the outlines of the eyes, ears, limbs are visible. The uterus reaches 8 cm, the sensitivity of the breast increases.
8-11	30 000-290 000
12-16	6 200-103 000	HCG levels gradually drop
17-21	4 700-80 000	The content of hCG decreases by about 5 times
22-39	2 600-78 000	The placenta begins to fully work (provides nutrition and protection for the fetus in the womb)

Growth dynamics by days in the presence of chromosomal abnormalities of the fetus

If fetal pathologies are detected, it is important to conduct an examination in the first trimester (blood test for hCG and ultrasound). From weeks 10 to 13, indicators are calculated for two markers: hCG and plasma protein A, and at 17 - hCG, AFP, estriol-A.

Diagnostic results for days that exceed the norm by 2 times are a sign that the child has Down's disease. And the indicators for the days, which are 2 times lower than the established ones, are a sign of Edwards syndrome, Patau or neural tube malformation. After that, a number of additional examinations are carried out to confirm such chromosomal abnormalities.

The ready-made answers indicate the risk coefficient MoM (Multiple of Median), which means the degree of deviation of the hormone from the norm at this stage of pregnancy. It is calculated according to the following calculation: MoM \u003d V / Me (V is the indicator of the marker protein, Me is the median of the marker protein, depending on the week).

The final risk coefficient is also adjusted taking into account the weight, the individual characteristics of the woman, her bad habits and diseases. And only then (after several diagnostics by the day) does the geneticist make the final diagnosis of a chromosomal abnormality.

When it decreases naturally during pregnancy

If at the first stages of pregnancy, the level of hCG increased in a matter of days by several tens of times, then starting from the 12th week, these figures fall at lightning speed by 2 times. They remain so until the end of the pregnancy. This natural decrease in hCG levels occurs because the placenta begins to function on its own and no longer needs to be maintained by the hormone.

It is impossible to completely protect the expectant mother and her child from abnormalities in the development of the fetus and diseases. However, often, many complications can be avoided if you just take tests on time and take preventive measures.

Useful video

An analysis for hCG shows pregnancy from the 7th to 10th day after conception. It is very informative, since there are practically no other conditions, except for pregnancy, with an increased value. That is why the preparation for surrender includes only the refusal of food. Blood sampling is done in the morning, on an empty stomach. The results help determine pregnancy with an accuracy of 2-3 days in the early stages. The analysis is also used to diagnose ectopic pregnancy and hydatidiform mole.

What is HCG

Human chorionic gonadotropin is a hormone produced by a fertilized egg. After the introduction of a fertilized egg into the wall of the uterus, the hCG produced stimulates the development of the placenta. There are two subunits of the hormone - alpha and beta. Alpha is identical to thyroid-stimulating hormone and luteinizing hormone, beta is unique to human chorionic gonadotropin.

Its main functions are:

Increase in progesterone and estrogen.
Stimulation of the gonads and adrenal glands in the fetus.
Preparation of immunity for pregnancy.
Stimulation of Leiding cells responsible for the production of testosterone in male embryos.

There are very few conditions in the body in which this hormone is produced. That is why the analysis for beta-hCG helps to find out as quickly as possible whether pregnancy has occurred or not. It is also possible to determine if fertilization has occurred after implantation of the egg, which occurs on the 7th - 10th day. Hormones are produced throughout pregnancy and disappear a week after childbirth.

Varieties of hCG analysis

There are several types of analyzes, each with its own purpose. Total beta-hCG is needed to determine if pregnancy has occurred. He can show pregnancy even when there is no second strip on the test yet (starting from the 7th day after conception). It is often used to diagnose pregnancy during IVF. In this case, not the days after the alleged conception are counted, but the days after the transfer.

Determining the duration of pregnancy by hCG:

days from conception	DPP 3 days	DPP 5 days	Possible values	The average

As pregnancy progresses, it increases and reaches its maximum by the tenth week, then its concentration begins to decrease. In the second trimester, with a high probability of Down syndrome and to exclude serious developmental pathologies in the fetus, an analysis for total hCG may be prescribed.

Analysis of free beta-hCG is used to diagnose tumor formations. This is a malignant formation of the testicles and choriocarcinoma. The latter develops after a failed pregnancy - hydatidiform mole. The same indicator is evaluated during screening for chromosomal abnormalities in the first and second trimesters of pregnancy. Deviation from the norm puts a woman at risk. Then invasive research methods are prescribed, a puncture of the fetal bladder to exclude Down and Edwards syndrome. It is recommended to be screened for pregnant women over the age of 35, people with Down syndrome in the family, affected by exposure to high doses of radiation.

Ultrasound diagnostics in the first trimester. Performed as part of screening for chromosomal abnormalities along with free beta-hCG

Preparation for delivery and terms for determining pregnancy

HCG increases in a woman's body starting from the 6th to 10th day after the expected date of fertilization, so it can show if pregnancy has occurred even before the delay in menstruation. With the help of the test, you can also determine whether conception has occurred, but you will have to wait 12-14 days after ovulation. It is believed that the result of both the analysis and the test is false positive up to 5 days from the first day of the expected menstruation. To verify the reliability of the result, it is necessary to repeat the analysis after two days. By the rate of its growth, you can determine whether the pregnancy is developing normally: the value should double.

Blood is also given after a medical abortion. If hCG does not decrease, this may indicate that a fetal egg remains in the uterus. In this case, scraping may be necessary.

The rules for preparing for the analysis are as follows: it is necessary to donate blood for hCG in the morning, before the analysis you can drink only water, food is excluded. The last time you can eat is 10-12 hours before delivery. It is recommended to avoid emotional experiences, to exclude alcohol and cigarettes a few days before the analysis. The analysis is being prepared in the laboratory, it will take several hours to wait for the result. In some clinics, the result is reported on the second day.

Deciphering indicators

An increase in hCG in the body of a pregnant woman indicates that she has:

multiple pregnancy;
toxicosis or gestosis;
high level blood glucose;
some deviations in the development of the embryo;
incorrectly determined gestational age.

After an abortion, hCG will show an increased value for about a week. If the indicator has not decreased, you should consult a gynecologist.

Decryption hCG results by weeks of pregnancy is presented in the table:

If hCG is too low during pregnancy, this indicates that the fetal development period is not set correctly. There are a number of reasons that can lead to a low level of hCG in the body of a pregnant woman:

frozen pregnancy;
fetal development disorders;
interruption risk:
ectopic pregnancy, the fetus is outside the uterus.

With the help of hCG, you can determine possible defects in the fetus, but it is not worth drawing conclusions only on the basis of one analysis. With the help of hCG, it is determined whether a pregnant woman is at risk. If hCG has shown that pathologies are possible, the patient is sent for additional studies, she is under the supervision of specialists.