Ectopic pregnancy can be detected as early as 5-6 weeks of pregnancy. In women with regular menstrual cycles, the intrauterine gestational sac can be seen by transvaginal gynecologic ultrasound after 5-6 weeks of menopause, when the sac can be a simple empty sac with no echogenic structures, or it can appear as an embryonic structure such as a yolk sac or germ. If the intrauterine gestational sac is not seen at this stage by transvaginal gynecologic ultrasound, the risk of ectopic pregnancy will be further increased and subsequent gynecologic ultrasound and monitoring of blood HCG will be required to differentiate it from intrauterine pregnancy such as preterm abortion or cessation of embryonic development in intrauterine pregnancy. The possibility of ectopic pregnancy is considered after no intrauterine gestational sac is detected by gynecological ultrasound or after a mass is found on the adnexa outside the uterus. If embryonic tissue structures such as yolk sac, germ or even fetal heart are present on the adnexal mass, the diagnosis of ectopic pregnancy can be fully confirmed. Due to the high frequency of conditions such as inflammation of the fallopian tubes in women, blockage of the fallopian tubes to varying degrees occurs, which affects the operation of the embryo in the fallopian tubes and increases the risk of ectopic pregnancy, and early gynecological ultrasound examination is needed after pregnancy to exclude the risk of ectopic pregnancy.