Usually, the number of embryos that will be transferred depends on how old you are and how many eggs have been retrieved. The implantation rate is lower in older women, so more embryos are typically transferred, except when the donor egg or genetically-tested embryos are used. To prevent higher-order multiple pregnancies, most doctors follow strict guidelines. Some countries have restrictions on the number of embryos that may be transferred. Before you agree to transfer embryos, ensure that you and your doctor are on the same page.