What is Beta Human Chorionic Gonadotropin (Qualitative)?
Human chorionic gonadotropin is a glycoprotein hormone secreted by syncytiotrophoblast cells of the placenta following implantation. The intact molecule comprises an alpha subunit shared with luteinising hormone, follicle-stimulating hormone, and thyroid-stimulating hormone, and a unique beta subunit that confers immunological specificity. Serum β-hCG becomes detectable approximately 6–8 days after conception, doubling every 48–72 hours in early viable pregnancy, and peaks at 8–11 weeks of gestation before declining to a plateau that persists throughout the second and third trimesters. Outside pregnancy, detectable β-hCG may be produced by trophoblastic tumours, germ-cell neoplasms, and certain non-trophoblastic malignancies.