If the HCG drops at eight weeks of pregnancy, it is recommended to recheck every other day if the magnitude is small. If the HCG still continues to drop, it is important to rule out the possibility of embryonic arrest. If there is a heart tube pulsation or a yolk sac on the previous ultrasound, and then the ultrasound is repeated after the HCG drop at eight weeks, and there is no heart tube pulsation or yolk sac, or the gestational sac does not continue to grow larger, it is possible that the embryo has stopped developing. If the embryo stops developing, you will need to be hospitalized to terminate the pregnancy. The termination of pregnancy can be done through abortion or medication. After hospitalization, the doctor in charge will make the appropriate referral. Therefore, if the HCG drops at eight weeks of pregnancy, an ultrasound must be done to rule out whether it is an embryonic arrest.