After 7 weeks of gestation, if the ultrasound still shows an empty gestational sac with no yolk sac or germ tissue, the embryo itself is not considered viable and has no chance of continuing to develop. With the improvement of ultrasound technology, in women with regular menstrual cycles, the germ and heart tube can be seen in the sac after 5 weeks of gestation, and the germ is rod-shaped and about 2.5-3 cm long. If the ultrasound shows an empty gestational sac at 5 weeks of gestation, it is necessary to review the ultrasound after 1 week to understand the development of the gestational sac and the appearance of the germ and yolk sac. If the ultrasound still indicates an empty gestational sac at 6 weeks of gestation, it should be considered: 1) indolent abortion: the embryo stops developing and the embryo dies; 2) empty gestational sac artifact caused by ectopic pregnancy; in the above cases, further blood tests of hCG and progesterone are needed to determine the rise and fall of hormone levels. In the above cases, further blood hCG and progesterone tests should be performed to determine whether the pregnancy is intrauterine or not and whether the embryo is dead. Therefore, if the ultrasound repeatedly indicates an empty gestational sac, the prognosis of embryonic development is not good, regardless of intrauterine pregnancy or ectopic pregnancy.