HCG QUANTITATIVE (SERUM)

Overview

Human chorionic gonadotropin (hCG) is a glycoprotein hormone (molecular weight: MW approximately 36,000 Dalton: Da) consisting of 2 noncovalently bound subunits. The alpha subunit (92-amino acids; naked protein MW 10,205 Da) is essentially identical to that of luteinizing hormone (LH), follicle-stimulating hormone, and thyrotropin (previously known as thyroid-stimulating hormone: TSH). HCG appears in the blood and urine of pregnant women as early as 10 days after conception. Quantitative HCG measurement helps determine the exact age of the fetus. It can also assist in the diagnosis of abnormal pregnancies, such as ectopic pregnancies, molar pregnancies, and possible miscarriages Children(1,2) Males Birth-3 months: < or =50 IU/L* >3 months-<18 years: <1.4 IU/L Females Birth-3 months: < or =50 IU/L* >3 months-<18 years: <1.0 IU/L *Human chorionic gonadotropin (hCG), produced in the placenta, partially passes the placental barrier. Newborn serum beta-hCG concentrations are approximately 1/400th of the corresponding maternal serum concentrations, resulting in neonate beta-hCG levels of 10-50 IU/L at birth. Clearance half-life is approximately 2-3 days. Therefore, by 3 months of age, levels comparable to adults should be reached. Adults (97.5th percentile) Males: <1.4 IU/L Females Premenopausal, nonpregnant: <1.0 IU/L Postmenopausal: <7.0 IU/L