Clinical Information

Human chorionic gonadotropin (hCG) is a glycoprotein hormone secreted by the developing placenta shortly after fertilization. In normal pregnancy, hCG can be detected in serum as early as 7 days following conception. Recent studies suggest that urine hCG concentrations are approximately one-half of, or less than one-half, of corresponding serum hCG concentrations. Thus, hCG can likely be detected in urine as early as 14 days after conception (approximately 28 days since the last menstrual cycle), doubling in concentration about every 2 days until it peaks at approximately 8-10 weeks after the last menstrual period. The appearance of hCG soon after conception and its subsequent rise in concentration during early gestational growth makes it an excellent marker for the early detection of pregnancy.