Pregnancy test

hCG, human chorionic gonadotropin, is a hormone that is formed and released from the placenta in connection with pregnancy. hCG is excreted in both the blood and the urine, and analysis of hCG can therefore take place in both of these. The production of hCG begins very early during pregnancy and can be measured in both blood and urine as early as nine days after conception. The maximum value is usually seen in the ninth week of pregnancy and thereafter the levels gradually decrease to a relatively constant, but lower, level during the remainder of the pregnancy.