The decrease in HCG may be due to embryonic abortion or ectopic pregnancy, while the increase in the size of the mass due to the decrease in HCG mostly occurs in cases of ectopic pregnancy. In ectopic pregnancy, there may be a decrease in HCG and an enlargement of the mass. The enlargement of the mass is due to internal bleeding and the blood cannot flow out from the mass, resulting in the enlargement of the mass. If the patient is in good condition, without active bleeding, and has the need for fertility, conservative treatment methods such as activation of blood circulation and embryo killing can be adopted, but if the patient is in poor condition, with obvious active bleeding and intra-abdominal bleeding, surgical treatment can be performed. HCG is an indicator to detect conception, indicating the activity of the fetus, and the normal HCG value is between The normal HCG value is between 0 and 10 IU/L. Generally, the value increases significantly after pregnancy, and when the fetus stops developing, it may not produce HCG anymore, so the value will decrease. If the HCG value does not increase significantly but decreases, it is recommended to test progesterone at the same time, which can also reflect whether the fetal development is normal or not, and once it is clear that the embryo has stopped developing, the pregnancy should be ended as soon as possible.