It is normal for the blastocyst to survive in the uterus for 280 days until delivery. If the embryo stops developing due to genetic deficiency, insufficient progesterone in the body, trauma or exposure to toxic and harmful gases or objects, the exact survival time is uncertain. In the vast majority of cases, the development stops in the early stages of pregnancy and the pregnancy needs to be terminated. For early pregnancy, must regularly review, if once suddenly early pregnancy reaction disappears, be alert to whether due to the embryo has died caused by the suggestion of ultrasound examination, blood HCG and progesterone laboratory tests, and then give a confirmation of the diagnosis.