Beta-chorionic gonadotropin in the blood and urine
Last reviewed: 31.05.2018
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Reference values of beta-chorionic gonadotropin in the blood serum in adults - up to 5 mead / l; in the urine during pregnancy at the period of 6 weeks - 13 000 IU / day, 8 weeks - 30 000 IU / day, 12-14 weeks - 105 000 IU / day, 16 weeks - 46 000 IU / day, more than 16 weeks - 5000- 20 000 IU / day.
Beta-chorionic gonadotropin is a glycoprotein secreted by the syncytial layer of trophoblast during pregnancy. It supports the activity and existence of the yellow body, stimulates the development of the embryoblast. Excreted in the urine. Detection in serum or urine serves as a method for early diagnosis of pregnancy and the pathology of its development. Oncology is used to control the treatment of trophoblastic and germinogenic tumors.
The concentration of beta-chorionic gonadotropin in the blood and its excretion in the urine increase already on the 8th day after fertilization. In daily practice, it is recommended to evaluate the dynamics of changes in the concentration of beta-chorionic gonadotropin. At the initial stages of physiological pregnancy, the concentration of beta-chorionic gonadotropin in the blood plasma increases 2 times every 1.98 days; An increase in the level of chorionic gonadotropin by less than 66% in 48 hours in 85% of cases indicates ectopic pregnancy or spontaneous miscarriage. Elevated concentrations of beta-chorionic gonadotropin in the blood in the absence of ultrasound signs of pregnancy (both in the uterus and outside it) serve as an indication for diagnostic laparoscopy. However, it should be borne in mind that with interrupted tubal pregnancy, the concentration of beta-chorionic gonadotropin in the blood quickly comes to normal. More than 95% of women with ectopic pregnancy have a positive beta-chorionic gonadotropin test. Only in a very small part of women with an ectopic pregnancy in a screening test, the test result is negative, although in a quantitative analysis they still detect an increase in the concentration of beta-chorionic gonadotropin.
Difficulties in diagnosing arise in those cases when the data of objective examination do not allow to determine the presence of pregnancy, and with ultrasound can not accurately determine the localization of pregnancy. In such cases it is necessary to determine the quantitative concentration of beta-chorionic gonadotropin in serum. If the level of beta-chorionic gonadotropin reaches 5000-6000 IU / ml, then ultrasound examination of the pelvis should look for an intrauterine pregnancy. In most cases, in women with ectopic pregnancy, the concentration of beta-chorionic gonadotropin in the serum does not exceed 3000 U / ml. The high content of chorionic gonadotropin in the blood or urine is very likely to indicate a uterine pregnancy.
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