HCG is human chorionic gonadotropin, a glycoprotein secreted by placental trophoblast cells, a hormone unique to pregnancy that allows the menstrual corpus luteum to become the corpus luteum of pregnancy, thus maintaining the normal development of the gestational sac. Insufficient secretion of human chorionic gonadotropin after pregnancy can easily lead to miscarriage during early pregnancy. Human chorionic gonadotropin can be detected by blood tests about a week after fertilization, and doubles every other day at about six weeks of pregnancy, and the concentration in the body is relatively stable by about the third trimester, and the pregnancy reaction will ease or disappear. If elevated HGC levels occur during the non-pregnant period, it is considered to be related to ovarian tumors.