HCG is not progesterone, but two different hormones: HCG, also known as human chorionic gonadotropin, is a glycoprotein secreted by placental trophoblast cells, and progesterone is a natural progestin secreted by the corpus luteum of the ovary. HCG can be detected in peripheral blood 7 days after fertilization and formation of a fertilized egg, and rises rapidly from 6 to 8 weeks of pregnancy, increasing 1-fold every 2-3 days, reaching a peak from 8 to 10 weeks of pregnancy, after which it declines and tends to plateau. HCG can help diagnose early pregnancy and pregnancy-related diseases, and a normal doubling of HCG in early pregnancy indicates normal embryonic development, while an abnormal rise in HCG indicates If the HCG is abnormally elevated, it is indicative of diseases such as staphyloma and choriocarcinoma. If HCG rises slowly in early pregnancy or has a tendency to decline, it suggests the possibility of ectopic pregnancy, embryonic abortion and preterm miscarriage. The main role of progesterone is to maintain the pregnancy and has a supportive and protective effect on the early development of the embryo. A low progesterone value may lead to fetal growth retardation, fetal arrest, or even preterm miscarriage, and embryonic dysplasia itself can also lead to low progesterone values. In addition, progesterone is an important indicator of menstrual cycle and luteal function. HCG stimulates the body to produce progesterone, which works synergistically with progesterone to protect the embryo and provide it with nutrients. Therefore, monitoring the level of HCG and progesterone in the blood during pregnancy should be followed by medical advice, which is meaningful for the preservation and maintenance of pregnancy.