Human chorionic gonadotropin (hCG) – is a hormone that is produced in the human embryonic fetal shell. It is an important indicator of the development of pregnancy and its deviations. It is produced chorionic cells (embryonic membrane) immediately after its attachment to the uterine wall (this happens only a few days after fertilization). The embryo at this stage of pregnancy is a microscopic vesicle walls filled with a liquid which consists of rapidly proliferating cells. From one part of these cells and developing unborn child (embryoblast), while from the cells that are outside of the embryo is formed trophoblast – that part of the ovum by means of which it attaches to the uterine wall. Subsequently of trophoblast forms the chorion buy clenbuterol uk.
Chorion has the function of the embryo supply, as a mediator between the mother’s body and the baby. In addition, it produces human chorionic gonadotropin, which is, on the one hand, affect the formation of the child, on the other – in a specific way affects the mother’s body, providing a safe course of pregnancy. The emergence of this hormone in the body of the expectant mother in the early stages of pregnancy, and explains the importance of the test for the early diagnosis of pregnancy.
Human chorionic gonadotropin stimulates the secretory function of the corpus luteum, which should produce the hormone progesterone , which supports normal inner shell wall of the uterus – the endometrium. Endometrium provides a reliable attachment of the ovum in the mother’s body and his food all the necessary nutrients.
Thanks to a sufficient amount of human chorionic gonadotropin yellow body, normally there is only about 2 weeks during each menstrual cycle, when successful conception is not subject to resorption and remain functionally active for the duration of pregnancy. And it is in pregnant women under the influence of human chorionic gonadotropin, it produces very large amounts of progesterone. Additionally, hCG stimulates the production of estrogen and androgen weak ovary cells and promotes the functional activity of the chorion, and further the placenta, which is formed by the maturation and proliferation of chorionic tissue, improving its own power and increasing the amount of chorionic villi.
Thus, the role of human chorionic gonadotropin is a specific and multifaceted impact on a woman’s body and the fetus in order to successfully pregnancy. Based on analysis determined the presence of human chorionic gonadotropin in women chorionic tissue and thus pregnancy.
Chemically chorionic gonadotropin is a protein compound and a complex carbohydrate composed of two parts (subunits): alpha and beta. Alpha-subunit of human chorionic gonadotropin is completely identical to the alpha subunit of luteinizing hormone, follicle-stimulating hormone and thyroid-stimulating the pituitary gland, which perform functions, in many respects similar to the function of human chorionic gonadotropin, but not during pregnancy. Beta-subunit of human chorionic gonadotropin is unique in that, on the one hand, determines the specificity of its actions, and on the other – makes it possible to identify it in a biological environment. Therefore, this test is called “beta-subunit of human chorionic gonadotropin (beta-hCG).”
Knowing the level of beta-HCG in the blood, it can have on the 6-8 th day after conception diagnose pregnancy (urine concentration of beta-hCG reaches the diagnostic level for 1-2 days later). In a normal pregnancy during the period between the 2nd and the 5th week of the number of beta-hCG doubles every 1.5 days. A multiple pregnancy is increased in proportion to the number of fetuses. HCG reaches a maximum level at 10-11 th week and then gradually decreases. This is due to the fact that since the beginning of the 2nd trimester of pregnancy the placenta alone is capable of producing enough estrogen and progesterone, with the participation of the endometrium which normally operates independently of the secretion of hormones in the corpus luteum of the ovaries. Then the concentration of hCG in the blood of pregnant women is gradually reduced, and yellow body can function without affecting hCG. During this period, the role of the hormone is to stimulate the production of testosterone in the fetus, which is necessary for normal development of the external genital organs of the embryo.
Thus, during pregnancy levels of beta-hCG in blood initially increases and then decreases. According to this indicator, you can judge the favorable course of pregnancy and detect violations of fetal development. The test for hCG in the blood – the most reliable method for determining early pregnancy. HCG appears in the body of a woman c 6-8-th day after fertilization. Common rapid pregnancy test, which can take advantage of every woman in the home, too, is based on the measurement of hCG in the urine.
Hormone levels are lower than normal at various stages of fetal development lead to the assumption of an ectopic pregnancy, a delay in the development of the fetus, the threat of spontaneous abortion, non-developing pregnancy or lack of function of the placenta. The cause of the increased content of beta-hCG can be toxemia, diabetes or wrong gestational age. High levels of the hormone after a mini-abortion indicate ongoing pregnancy.
Determination of hCG level is part of the triple test study, the results of which can be seen on some fetal abnormalities, but it is impossible to put an accurate diagnosis. The study can be attributed to a woman at risk for this disease. In this case, the need for further examination. In nonpregnant normal hCG is absent, however, it can be secreted by some abnormal tissues derived from CVS (molar pregnancy, horionepitelioma), and some other tumors.
Why use the research?
- For the diagnosis of pregnancy, including multiple and ectopic and non-developing.
- To monitor the pregnancy.
- In order to identify delays in the development of the fetus, the threat of miscarriage, insufficient placental function.
- For the diagnosis of amenorrhea.
- To monitor the effectiveness of induced abortion.
- As part of a comprehensive survey to identify fetal malformations.
- For the diagnosis of tumors producing hCG.
When the assigned study?
- If you suspect a pregnancy, particularly multiple.
- When monitoring the progress of the pregnancy.
- When there is an assumption of complications during pregnancy: fetal growth retardation, the threat of miscarriage, ectopic pregnancy, or not developing, chronic insufficiency of function of the placenta.
- If necessary, confirm the success of the abortion.
- When the comprehensive examination to detect fetal abnormalities.
- When establishing the reason for the absence of menstruation (amenorrhea).
- When tumors are diagnosed producing hCG.