One of the most accurate methods for determining early pregnancy is a blood test for the amount of hCG hormone. The beta particle of human chorionic gonadotropin is a unique unit of glycoprotein that is produced after the embryo is attached to the uterus. Its blood parameters vary depending on the duration of pregnancy and play an important role in the synthesis of the hormones estradiol, progesterone and estriol. Those who are interested in their “interesting” position will not be difficult to accurately determine the presence of pregnancy by donating blood for hCG. What this is, how the procedure goes, when to go through it and how to evaluate the results, we will consider in the article.
What is hCG?
Human chorionic gonadotropin is a hormone with a protein structure. It is produced by the tissues of the developing embryo throughout the entire period of gestation. Thanks to this substance, the function of the ovaries is inhibited. New eggs cease to ripen, and the next menstruation does not occur. HCG tunes the female body to bear pregnancy, contributing to the implementation of hormonal changes.
This glycoprotein consists of two particles: alpha and beta. Alpha-hCG is similar to other body hormones, while the beta unit is unique. Therefore, when conducting the analysis, they are focused specifically on the concentration of beta particles.
A small presence of the hormone in the human body is considered normal in the absence of pregnancy. It is produced by the pituitary gland. Sometimes a certain amount of the hormone is found in the body of men and non-pregnant women. The norm of hCG in the blood is up to 5 mIU / ml, and for women during menopause - up to 9.5 mIU / ml.
How to determine pregnancy by blood test?
The level of human chorionic gonadotropin in the body of a woman has become a universal indicator of pregnancy. Express strips are arranged just by this principle. They respond to the level of the hormone in the urine, which begins to increase markedly 2 weeks after fertilization. However, the tests are not always accurate, and besides, with their help it is impossible to say exactly about the gestational age. Therefore, women suggesting the completion of conception, it is recommended to donate blood for hCG. What is it? A routine procedure performed in any private or public laboratory.
The results obtained are highly accurate. Many women are interested in the question: "Blood on hCG when will pregnancy show?" Obstetrician-gynecologists recommend not to rush and think about conducting an analysis only after a delay. The minimum period after which it is possible to determine pregnancy is 7 days from the moment of conception.
When can I donate blood for hCG?
Despite the fact that a blood test is a highly accurate and affordable method that allows you to find out about pregnancy, you should think about the timing of its conduct. Of course, nothing prevents you from contacting a diagnostic laboratory a couple of days after conception. But the results of such an analysis will not be reliable. And yet, when can I donate blood for hCG to get accurate pregnancy data? Doctors recommend the following dates:
- if a woman knows exactly the day of conception, then 2 weeks should be counted from it. On the received date and schedule an analysis;
- in cases where it is impossible to determine the moment of conception, it is considered appropriate to take an analysis 3 weeks after the delay of menstruation.
To obtain reliable results, you should be patient and wait for the recommended period.
How to take an analysis and how much does it cost?
Inexperienced in pregnancy and motherhood women are asked many questions about the analysis. How to take hCG, what rules must be observed? In fact, everything is much simpler than it seems. Blood for hCG is taken from the ulnar vein in an amount of 5 ml. It is advisable to come for analysis in the morning and eat nothing before the procedure. Before receiving a doctor’s referral, it’s better to warn about taking medications. This may affect the results of the study.
What is the cost of a blood test for hCG? Price may vary by laboratory. On average, the service will be 500 rubles, in the capital - about 800 rubles. This applies to private clinics and diagnostic centers. In a budgetary institution at the place of residence, a direction is issued free of charge.
Interpretation of primary results
Having decided on when it is better to donate blood for hCG, having passed the procedure and getting the coveted result, I want to know more about what the numbers on the analysis statement mean. There are three possible scenarios:
- Negative - the hormone is defined in the amount of from 0 to 5 mIU / ml.
- Doubtful - chorionic parameters are fixed in the range of 5–25 mIU / ml.
- Positive - hCG in the blood exceeds 25 mIU / ml.
Upon receipt of a dubious result (a slight increase in the hormone), it is recommended to re-analyze it after a few days. In this case, it is advisable to observe the same conditions for blood sampling and diagnosis: to come to the same clinic, at the same time of day and on an empty stomach. The new result is compared with the previous one. If the deviation in one direction or another is preserved and exceeds 50% of the norm, a conclusion is drawn about the presence of a pathological process (a sign of tumors). In the case of a 20% deviation from the set values, the result is again called into question, appointing a new study. In some cases, with the stability of the results and the absence of pathologies, a conclusion is drawn about the individual level of the hormone chorion in the blood.
A single analysis is performed only if a negative result is obtained, in which doubt does not arise over time. When confirming pregnancy, it is necessary to periodically monitor the hCG hormone.
Changes in test results by week of pregnancy
In the first weeks of pregnancy, the level of the hormone chorion in the blood increases significantly. The growth rate is considered in the days necessary to double it:
- up to 6 weeks - 2;
- 6-8 weeks - 3;
- 8-10 weeks - 4.
By the 11th week of pregnancy, the result of a hCG blood test will show the maximum value. After which a gradual decline will begin. At 16 weeks, the indicator will be identical to a 7-week pregnancy. In the remaining period of gestation, the hormone level will remain stable.
Change in the amount of hCG in the blood, depending on the gestation periodWeek from conception | HCG level, mIU / ml |
1 | 50-100 |
2 | 2 500-6 500 |
3 | 11 000-25 000 |
4 | 36,000-73,000 |
5 | 64,000-116,000 |
6 | 27 000-233 000 |
7–11 | 20,000-291,000 |
12-15 | 6,200-103,000 |
16–20 | 4 800-80 100 |
21–39 | 2 700-78 100 |
The spread of the level of the hormone chorion is very high: all options in the specified range are considered normal. In addition, only a doctor can reliably interpret the results. Sometimes the individual level of the hormone in the blood is slightly higher or lower than the standard.
HCG indicators for IVF
If a woman has undergone IVF, then the procedure for the analysis will change slightly. Blood for HCG when will pregnancy show in such a case? The answer of experts is as follows: the procedure should be completed no earlier than 12 days after the injection containing the hormone chorion. The table shows the average values of hCG in the blood after implantation of the embryo into the uterine cavity.
The norm of the human chorionic gonadotropin hormone in the blood after IVFThe age of the embryo (puncture day is considered zero) | The average value of hCG, mIU / ml |
1 | 4 |
2 | 105 |
3 | 2,000 |
4 | 11 500 |
5 | 31,000 |
6 | 65,000 |
How to take hCG if injections with its content were prescribed after the implantation of the embryo in order to maintain the corpus luteum? You should wait a few days before doing the analysis. Otherwise, the results will be overestimated.
High levels of hCG in the blood
Most pregnant women are almost unaware of their level of hCG. If everything is in order, the doctor rarely tells the expectant mother about the results of each examination. Another thing is when problems arise. HCG in the blood may be higher or lower than normal. And only with rare exceptions, this does not indicate a pathology of the development of the fetus or the health of the mother.
What do the overestimated figures in hCG analysis hide? Sometimes it’s nothing serious: incorrect setting of the term or multiple pregnancy. However, often the suspicion falls on a woman having diabetes mellitus, toxicosis or pathologies in the development of the embryo. If an increased level of hCG in the blood is detected, a second analysis and an additional examination of the expectant mother are prescribed.
Low hCG
The level of the hormone chorion in a woman’s blood allows with high accuracy not only to detect pregnancy in the early stages, but also to monitor the development of the embryo throughout the entire period of gestation. HCG is a specific hormone of motherhood. His understated indicators, as a rule, speak about violations of the course of pregnancy:
- threatened miscarriage;
- a delay in embryo development;
- fetal death;
- "Fading" of the embryo;
- ectopic pregnancy;
- pathology of the placenta or fetus.
Any deviation from the norm in the results of analysis for hCG is an alarming sign requiring immediate medical attention for advice.
Should I rely on the results of the analysis?
And yet, blood on hCG - what is it? How much can you trust a typical lab test? This procedure is similar to taking blood for hormones, because hCG is one of them. Reliability of the result at a high level: inaccuracies rarely occur, usually due to the use of drugs or the use of specific products on the eve of the analysis.
Laboratory tests may give a false positive or false negative response. In the first case, a high level of hCG, typical for a pregnant woman, is determined. Only after a while it becomes clear that the embryo in the uterine cavity is absent. Why is this happening? There are few options: either the drugs taken by the woman (including those containing hCG) are to blame, or this is a serious sign of pathology.
A false negative result usually occurs when the analysis is carried out too early. Anomalies in the development of the embryo in the early stages also occur. In any case, a repeat analysis and ultrasound are prescribed.
conclusions
HCG blood - what is it? It turns out a standard and very informative analysis. With its help, pregnancy can be diagnosed with high accuracy as early as 2 weeks after conception. HCG is a specific hormone produced by the tissues of the chorion (subsequently the placenta). After implantation of the embryo into the uterine cavity, its number increases sharply, stimulating the restructuring of the body to bear the fetus. HCG indicators characterize pregnancy in the best way possible and timely inform the expectant mother not only about the "interesting" situation, but also about failures in the baby's development.