IVF usually involves the transfer of 1 or 2 embryos, and in rare cases, 3 embryos are transferred. Generally speaking, women who choose to undergo IVF have difficulty conceiving naturally, in which case the doctor will choose to implant 2 embryos, or 1 embryo if the embryo and the endometrium are in good condition. However, for women who have extreme difficulty conceiving, such as those older than 35 or those who have not conceived after 2 or more embryo transfers, 3 embryos may be placed. More embryos are not better for IVF transfer, as more may require fetal reduction surgery, which can be more damaging to the organism. During the IVF process, if abnormal symptoms such as vaginal bleeding occur, you need to seek medical attention to avoid accidents.