A blood test can reliably ascertain whether there is a pregnancy in the earliest of its terms. A blood test enables you to set the timing of the pregnancy, when other research tools are still little information. Also, this method of blood testing allows dynamic control of pregnancy in the first trimester.

Based on what the analysis of blood

To establish the fact of pregnancy may be due to the determination of the content of a special hormone that is produced in women only during pregnancy. It is the hormone HCG, or human chorionic gonadotropin, his b-subunit. A hormone produced by cells of chorionic tissue, so the presence of this hormone can be argued that the woman is pregnant. The specificity of the blood test is that allows you to give an opinion on the presence of pregnancy, since the first days of its development, for example, for up to ten days from the moment of fertilization. Due to the high specificity can be recommended to the laboratory studies of blood for wide application in practice.

From the standpoint of the chemical structure of hCG is composed of two subunits (a and b), but only the second unit may be used for the laboratory diagnosis of pregnancy. It can be argued that this subunit is unique in its kind, and is based on what it found in the blood and the establishment of pregnancy. In determining the b-subunit also based urinary tests, but they are less reliable than blood analysis. The reason is that the achievement of the required level of hormone in urine occurs several days later when compared to the concentration in the blood. It is important that a blood test has been put right. To do this, you must make the collection of blood from the cubital vein in the morning on an empty stomach.

In some cases, you can assign this type of survey

Due to the unique properties of the HCG hormone analysis helps the doctor in many complex clinical situations. Establishment of a pregnancy at a very early period is the main indication for its use, but not the only one. There is a large group of indications for blood test for the presence of b-subunit. These indications are the following cases:

• absence of menstruation, or amenorrhea Amenorrhea - if you do not come monthly
• the need to exclude ectopic pregnancy or ectopic
• presence of complications of pregnancy (threat of interruption, developing pregnancy), the dynamic control of the development or progression of pregnancy
• diagnosis of certain tumors (molar pregnancy, horionepitelioma)

Each week of pregnancy there is a dynamic increase in blood levels of human chorionic gonadotropin. This occurs every two or three days. Based on the interpretation of the results of a blood test your doctor may draw a conclusion about how the development of pregnancy. The maximum levels of the hormone in the blood by the end of the first trimester (it is the gap between the tenth and twelfth weeks of pregnancy). Subsequently, the concentration of chorionic gonadotropin is reduced and during the second trimester remains constant. Before the appointment of the blood test is necessary to eliminate the fact of a woman taking drugs hCG, drugs (synthetic progestogens), as against the background of their receiving the result will exceed the allowable standards for performance.

In recent years, the definition of human chorionic gonadotropin included in the program of prenatal diagnosis for fetal congenital malformations. This blood test is used along with other methods of diagnosis defects - Determination of levels of estriol (free fraction) and AFP (alpha fetoprotein). If a woman is at risk for the birth of the fetus with a congenital pathology, the individual plan of pregnancy should include determination of b-subunit gonadotropin during the first trimester.

Marina Solovyov

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