Empty sac in pregnancy is a form of embryo termination, which may be related to the lack of nutrients in the mother, but also to embryonic factors, sperm factors and so on. Empty sac in pregnancy means that when a pregnant woman does an examination around fifty days of pregnancy, she finds an empty gestational sac in the uterine cavity, and there is no fetal heart or buds in the sac. Empty sacs may be related to the lack of various nutrients in the mother’s body and the insufficiency of her own endogenous hormones, but it may also be related to chromosomal abnormality of the embryo, infection of the embryo by pathogenic germs, luteal insufficiency and thyroid function abnormality, and so on. In addition to the above factors, men with reduced sperm quality, long-term exposure to X-ray or chemicals, etc., easy may cause pregnancy empty sac. Among them, old age of pregnant women, multiple pregnancies or previous history of fetal growth restriction or fetal termination are all predisposing factors and should be taken seriously. It is recommended that women with empty sacs in pregnancy should seek medical examination as soon as possible to clarify the cause of empty sacs and take active measures to prevent the recurrence of the accident.