After three injections of methotrexate for ectopic pregnancy, the blood HCG will usually drop. Methotrexate is a commonly used embryocidal drug in the conservative treatment of ectopic pregnancy. If the blood HCG is below 2000U/L, the diameter of gestational sac is less than 4cm, and there is no obvious intra-abdominal hemorrhage, abdominal pain and other symptoms, methotrexate can be used for treatment under the guidance of doctors. After applying methotrexate to women with ectopic pregnancy, the 1st check of blood HCG is after 3 days of using the medicine, and if the HCG value can drop to half of the initial check value, it proves that the effect is better. Generally ectopic pregnancy with three injections of methotrexate HCG can fall. Therefore, when ectopic pregnancy is treated conservatively with methotrexate, the blood HCG value will generally decline well after three injections, but if the effect is not good, timely surgical treatment is recommended to avoid the rupture of ectopic pregnancy and other serious consequences.