For women undergoing IVF transplantation, due to the different types of blastocysts transferred and the different physical conditions of each individual, the growth and development of the gestational sacs after transplantation will vary. If the woman is transferring fresh embryos into the uterine cavity, the corresponding time of menopause at the 27th day of the transfer is usually around 50 days of pregnancy, and the size of the gestational sac is mostly around 1.5-2.5cm, and most of the gestational sacs can be seen in the obvious fetal heart, fetal buds. If the frozen embryos are transferred into the uterine cavity, due to the fact that the frozen embryos have to be thawed and awakened in the uterine cavity before they can settle down and grow, the corresponding time of menopause at 27 days after the transfer may be around 45 days after the pregnancy, and the size of the gestational sac is around 1-2cm, and the obvious fetal heart and buds may not necessarily be seen.