Blood beta-chorionic gonadotropin measurement is used for early diagnosis and monitoring of pregnancy, for the investigation of patients with trophoblastic gestational disease (hydatidiform moles), for the evaluation and monitoring of patients with testicular tumors, and for the monitoring of ectopic pregnancies.
Human chorionic gonadotropin (hCG) is a glycoprotein hormone consisting of 2 linked subunits. The alpha subunit (92 amino acids) is substantially identical to that of luteinizing hormone (LH), follicular hormone (FSH), and thyroid hormone (TSH). The different beta subunits of the above hormones are transcribed from separate genes and show less homology. The beta subunit of hCG differs from the pituitary hormones, resulting in its unique biochemical and immunological properties.
HCG is produced in the placenta during pregnancy. In non-pregnant women, it can also be produced from trophoblast tumors, trophoblast stem cell tumors, and some other tumors. The biological activity of hCG serves to preserve the corpus luteum during pregnancy while also affecting the production of steroid hormones.
Measurement of hCG concentration allows diagnosis of pregnancy from the first week after conception. HCG values are doubled every 3 days during the first 6 weeks of pregnancy. After childbirth, miscarriage, or termination of pregnancy, hCG falls with a half-life of 24 to 36 hours, until it returns to normal.
Elevated concentrations of human chorionic gonadotropin during the first trimester of pregnancy are occasionally observed in normal pregnancy, but may also be an indication of choroidal carcinoma, pregnancy, or multiple pregnancy.
The decrease in hCG concentration is indicative of threatened miscarriage, recent termination of pregnancy, ectopic pregnancy, or endometrial death.
Important Note
Laboratory test results are the most important parameter for the diagnosis and monitoring of all pathological conditions. 70%-80% of diagnostic decisions are based on laboratory tests. The correct interpretation of laboratory results allows a doctor to distinguish "healthy" from "diseased".
Laboratory test results should not be interpreted from the numerical result of a single analysis. Test results should be interpreted in relation to each individual case and family history, clinical findings, and the results of other laboratory tests and information. Your personal physician should explain the importance of your test results.
At Diagnostiki Athinon we answer any questions you may have about the test you perform in our laboratory and we contact your doctor to get the best possible medical care.
