Human chorionic gonadotropin (hCG) is far from the most famous component of the human body. Moreover, this term is hardly known even to every hundredth man, and among girls who were not yet pregnant, the knowledge about this hormone is not much wider. But despite this, hCG is one of the most important factors in the existence of the human race. No wonder it is called “pregnancy hormone.” About him, as well as the functions of this hormone, we will talk in as much detail as possible.
- Chorionic gonadotropin functions
- Laboratory measurements of hCG levels in the body
- Nuances of laboratory studies of the level of hCG in the body
- Human Chorionic Gonadotropin Norm
- Causes of deviations in the level of hCG from regulatory indicators
- Low-Level HCG Background
- Background to High Levels of HCG
To begin with, without certain pathologies, human chorionic gonadotropin is found only in the female body over a nine-month period, which is called pregnancy. Chorionic gonadotropin is synthesized at different stages of pregnancy by two different organs: in the first part of the nine-month period, the synthesis is carried out by a fertilized egg, and in the second – by the trophoblast (the outer ball of blastocyst cells, which later serve as the basis of the outer shell of the embryo). Moreover, the distinction between these stages is made by the formation of a trophoblast, which, in fact, is the precursor of the placenta.
In terms of its structure, hCG is a glycoprotein containing 237 amino acids. The basis of chorionic gonadotropin – two subunits – “α” and “β”. This nuance is crucial in terms of the characteristics of this hormone. The alpha subunit of hCG is a component that completely repeats analogous subunits of a number of other hormones. A specific element of the human hormone is the beta subunit. It is through it that the level of the substance is diagnosed and it is it that shows the normal course of pregnancy, or the presence of some pathologies.
Chorionic gonadotropin functions
The most significant function of hCG is the diagnosis of pregnancy. This hormone is the basis for the construction of pharmacy tests for determining pregnancy. The effectiveness of the testing method is determined by the fact that the hormone index in the female body changes dramatically almost immediately after fertilization of the egg has passed.
If a woman has no certain pathologies and is not in a state of pregnancy, the level of hCG in the blood is zero and only in rare cases can it reach four international units per liter (IU / l) with individual characteristics, then seven days after fertilization it grows to 50 IU / l. At the same time, this diagnostic method is specific – it determines only pregnancy, and is very sensitive, demonstrating high accuracy rates for determining pregnancy.
With regard to the functions of human chorionic gonadotropin in humans, there are three:
- 1. Stimulating the synthesis of glucocorticoids – hormones that contribute to the adaptation of the female body to pregnancy, which is a chronic immune stress.
- 2. In the first six weeks of gestation, the pregnancy hormone is the key to the normal functioning of the corpus luteum. It also synthesizes progesterone – another important hormone of the woman’s body in the position.
- 3. Assistance in the normal performance of the placenta. In particular, a sufficient level of hCG has a positive effect on the villi of the chorion.
Laboratory measurements of hCG levels in the body
Modern medicine offers several methods to determine the amount of hCG, among which the most popular are the so-called “rapid tests” for pregnancy. Their action is based on measuring urine hCG levels. In this study of urine to determine the level of this hormone is not the most sensitive method, but sufficient to confirm or deny the fact of pregnancy.
Chorionic gonadotropin is measured in urine and in laboratory conditions, but even then the accuracy is not high enough. The most sensitive method is a laboratory blood test. In addition to the fact that the result will be closest to the truth, the laboratory will also provide data on hCG standards for certain gestational periods and will be able to guarantee the quality of the study using the control schemes used.
Nuances of laboratory studies of the level of hCG in the body
Quite interesting is the fact that apart from determining the fact of pregnancy, the analysis of hCG in the blood is almost no good for anything else. And this, even despite the fact that in medicine there is an official table that shows the level of hCG by weeks of pregnancy and by the first days after fertilization of the egg.
Why, for example, it is impossible to determine the duration of pregnancy by the level of hCG? The fact is that in the normative tables, which we give a little lower, for each period are quite wide ranges of values. But even they are not the numbers, a deviation from which indicates the development of pathologies. Concerning hCG, only two facts are certain:
- It appears after fertilization of the egg,
- its level increases and decreases according to a certain pattern.
But the indicators of changes in the level of the hormone in absolute terms are individual for each woman. And they differ in the normal course of pregnancy can be at times. And hCG 1000 IU / l, for example, even at a certain period, one woman will have a normal indicator, the second – overestimated, and the third – low.
Therefore, regarding research on the amount of hCG, two things are the most important:
By adhering to these rules, you, at first place, will avoid unnecessary negative emotions by seeing in the analysis figures that fall outside the normal ranges. And, secondly, won’t make mistakes in determining the duration of pregnancy. Ultrasound diagnosis and counting from the date of the last menstruation is best suited for this task.
Another interesting nuance of diagnosing the volume of a hormone in a woman in a position is the unit of measurement. In particular, in the laboratory results, there are two options: IU / L and mIU / ml. The first one means, as already indicated above, “international units per liter,” the second one, “milli-international units per milliliter.” In this confusion, in principle, no no. These concepts are juxtaposed one to one. That is, regardless of what unit of measurement a particular laboratory uses, the numbers in the results will be exactly the same. For convenience, we will use the abbreviation “ME / L” in this material.
Human Chorionic Gonadotropin Norm
As we have already noted, hCG is a “hormone of pregnancy”, in men and women who do not bear a child, it practically does not occur, therefore, we will consider the norms for the period of bearing a child. In medicine, there are two tables of the values of this component:
- hCG table for weeks of pregnancy;
- hCG table for days from the second to the sixth week after ovulation.
|Week of Pregnancy||Normal range of hCG level|
|First week||5.3-50 IU / L|
|Second Week||50-500 IU / L|
|Third Week||101-4870 IU / L|
|Fourth Week||1110-31500 IU / L|
|Fifth Week||2560-82300 IU / l|
|Sixth Week||23100-151000 IU / L|
|Seventh Week||27300-233000 IU / L|
|8-11 weeks||20900-291000 IU / L|
|12-16 weeks||6140-103000 IU / l|
|17-21 weeks||4720-80100 IU / L|
|22-39 weeks||2700-78100 IU / L|
By day, in the first 42 days after ovulation, hCG rates are as follows:
|Day after ovulation||hCG level (average and normal range)||Day after ovulation||hCG level (average and normal range)|
|7||4 IU / L, 2-10 IU / L||25||6150 IU / l, 2400-9800 IU / l|
|8||7 IU / l, 3-18 IU / l||26||8160 IU / l, 4200-15600 IU / l|
|9||11 IU / l, 5-21 IU / l||27||10200 IU / l, 5400-19500 IU / l|
|10||18 IU / l, 8-26 IU / l||28||11300 IU / l, 7100-27300 IU / l|
|11||28 IU / l, 11-45 IU / l||29||13600 IU / l, 8800-33000 IU / l|
|12||45 IU / l, 17-65 IU / l||30||16500 IU / l, 10500-40000 IU / l|
|13||73 IU / l, 22-105 IU / l||31||19,500 IU / l, 11,500-60000 IU / l|
|14||105 IU / l, 29-170 IU / l||32||22600 IU / l, 12800-63000 IU / l|
|15||160 IU / l, 39-270 IU / l||33||24000 IU / l, 14000-68000 IU / l|
|16||260 IU / l, 68-400 IU / l||34||27200 IU / l, 15500-70000 IU / l|
|17||410 IU / l, 120-580 IU / l||35||31000 IU / l, 17000-74000 IU / l|
|18||650 IU / l, 220-840 IU / l||36||36000 IU / l, 19000-78000 IU / l|
|19||980 IU / l, 370-1300 IU / l||37||39500 IU / l, 20500-83000 IU / l|
|20||1380 IU / l, 520-2000 IU / l||38||45000 IU / l, 22000-87000 IU / l|
|21||1960 IU / l, 750-3100 IU / l||39||51000 IU / l, 23000-93000 IU / l|
|22||2680 IU / l, 1050-4900 IU / l||40||58000 IU / l, 25000-108000 IU / l|
|23||3550 IU / l, 1400-6200 IU / l||41||62000 IU / l, 26500-117000 IU / l|
|24||4650 IU / l, 1830-7800 IU / l||42||65000 IU / l, 28000-128000 IU / l|
Regarding the trend of changes in the level of hCG during pregnancy, it is necessary to note three regularities:
- It makes sense to determine the level of the hormone from 6-9 days after ovulation. Before that, its concentration is insufficient for qualitative analysis;
- He starts a pregnancy and until the ten-week period, with a regular course, the level of human chorionic gonadotropin doubles every two or three days;
- during the peak period that falls on the tenth week of pregnancy and up to the 20th week, the level of this hormonal component decreases approximately twice and the result remains almost unchanged until the moment of delivery.
Deviations from these three points are a reason for in-depth research and consulting a doctor. Absolute norms – the numbers are not very indicative and do not accept them as an axiom.
Causes of deviations in the level of hCG from regulatory indicators
It has already been noted that the norms of human chorionic gonadotropin in the body of a pregnant woman are not a paradigm. Deviation from them can be not only pathological, but also natural. Only a doctor should draw any conclusions regarding the hCG index at a certain period of pregnancy.
At the same time, there are well-defined lists of pathological causes that cause a deviation of the level of the “hormone of pregnancy” in one direction or another. Consider them in separate groups.
Low-Level HCG Background
- extrauterine development of pregnancy,
- threatened miscarriage
- extended gestational age,
- frozen fruit,
- developmental delay of the fetus.
In addition to these reasons, a reduced (as well as elevated) level of chorionic gonadotropin can be fixed due to an incorrect determination of the duration of pregnancy by a doctor. This situation is dangerous because in the normal course of the process of carrying a child, the woman is assigned an additional diagnosis, and sometimes treatment, which she absolutely does not need. Such situations are quite rare, but it is impossible not to mention them. In addition, the incorrect determination of the duration of pregnancy and, consequently, the incorrect diagnosis of a reduced level of hCG, may cause not the most pleasant emotional load of the future mother. The above reasons for insufficient concentration of the hormone will not add positive emotions to anyone, which are extremely important during the period of gestation.
Background to High Levels of HCG
- toxicosis and late toxicosis (preeclampsia),
- gallbladder (conception without normal embryo development),
- multiple pregnancies (HGR level increases in proportion to the number of fetuses),
- administering HCG-containing medications.
In addition, you need to separately highlight the causes of high levels of human chorionic gonadotropin in men and women who do not bear a child. In principle, they have elevated is any indicator other than zero. The following reasons may cause this:
- tumors of the gastrointestinal tract and testicles,
- malignant and benign lesions of a number of organs (kidneys, lungs, uterus),
- chorionic carcinoma is a malignant cancer, the development of which starts from embryonic structures.
Completing the examination of the characteristics of human chorionic gonadotropin, one cannot but mention a number of features of this hormone and its functioning in the body.
First, medicine knows cases in which women developed immunological resistance to hCG. Natural antibodies have inhibited the synthesis of the hormone, leading to spontaneous early abortions. The nature of this phenomenon remains unknown (it is assumed that intracellular infections lead to this, interruptions in the hormonal background or weak immunity), but it is not insoluble. When confirming the presence of antibodies to chorionic gonadotropin, a woman is prescribed medication based on low molecular weight heparins and glucocorticoids. The action of these drugs is effective enough to stop the work of immunity, aimed at suppressing hCG.
Secondly, there are two options in which pregnancy is not confirmed by the presence of hCG. This can happen when a pregnancy test is performed earlier than the ninth day after ovulation, and also when the pregnancy is ectopic. Therefore, compliance with the rules for the analysis of hCG levels, as well as consultation with a specialist in all problem cases, are extremely important.
Thirdly, sometimes chorionic gonadotropin in the form of a medical preparation is used in the treatment of a number of pathologies. There are three prerequisites for this:
- threatened early abortion,
- preparation for artificial insemination,
- infertility treatment.
Talking about the stable efficacy of exogenous chorionic gonadotropin, it is impossible. Nevertheless, the practice of using it even in these cases is not widespread and there is simply no reliable sample of the results of statistical analysis of the application.
Fourthly, recently, a number of medical and near-medical resources, as well as a number of specialized experts, argue that men and women outside the temporary period of gestation, hCG levels range from zero to five international units per liter . However, no research papers or statistical samples that confirm this statement are not given, which does not allow us to accept this thesis as reliable. So official medicine continues to assume that, with the exception of pregnant women, the level of hCG in humans is zero.
And the last thing: chorionic gonadotropin of exogenous origin is quite common as a doping drug in sports. Its alpha subunits are identical to similar components of luteinizing hormone, which in the human body is produced by the pituitary gland. By stimulating the germ cells in the ovaries, hCG in the body of a male athlete contributes to the production of testosterone, increasing the life of the body in terms of maintaining strength and mass.