Blood HCG is also elevated in ectopic pregnancy, but since the pregnancy is outside the uterus, the concentration of blood HCG in the body is lower compared to intrauterine pregnancy, and when blood is drawn for blood HCG testing again every other day, it does not double up from the original level, which is the main HCG manifestation of ectopic pregnancy. After monitoring the blood HCG of ectopic pregnancy, the initial clinical diagnosis of ectopic pregnancy can be made, mainly by ultrasound, which reveals the presence of a gestational sac outside the uterine cavity. For postoperative ectopic pregnancy or after miscarriage of ectopic pregnancy, the blood HCG will show a rapid decrease, while for conservative treatment of ectopic pregnancy, the blood HCG will decrease more slowly.