FET reduces costs significantly, and in some cases, increases the chances of success. The reason is that frozen embryos are already viable and fertilization has already occurred. In a brand new IVF cycle with no frozen embryos. Fertility doctors must retrieve eggs. Fertilize them with sperm, and then transfer. At any point in that process, IVF could fail. For example, some rounds of IVF result in no viable eggs to fertilize. Another round of IVF may result in no fertilized or healthy embryos. Fertility clinic data suggests that the FET success rate are similar to the success rate of a fresh IVF cycle. In other words, they are not significantly higher or lower if you consider one round at a time. However, in some cases, FET increases the chances of success in multiple rounds of IVF. Because of the significant cost savings as well as the increased chances of success, any patient with extra healthy embryos benefits from frozen embryo transfer.