Yolk sac but no fetal buds and heart may be related to the short duration of pregnancy and abnormal embryonic development, and it is recommended to pay attention to it in time. 1. Shorter pregnancy time: Yolk sac but no fetal buds and heart may be due to shorter pregnancy time, at this stage, the fetal buds and the fetal heart can not be well observed, you can review the ultrasound again after a period of time. 2. Abnormal embryonic development: the yolk sac but no buds and fetal heart may also be due to the early stage of pregnancy, the embryo gene loss or the existence of serious illnesses and other reasons, resulting in the cessation of embryonic development. It is recommended to terminate the pregnancy as soon as possible. There may be other reasons for having yolk sacs but no fetal heartbeat, so it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or therapy.