Frozen embryos are used in future IVF (in vitro fertilization) cycles as a part of a process known as frozen embryo transfer (FET). Embryos that are not transferred during a fresh IVF cycle can be cryopreserved or frozen for future use. These frozen embryos can then be thawed and transferred into the uterus during a later cycle, offering several benefits:

1. Increased success rates: Frozen embryo transfer allows for better synchronization between the embryo and the uterine lining, potentially increasing the chances of implantation and a successful pregnancy compared to fresh embryo transfers.

2. Improved timing and flexibility: Frozen embryo transfer provides flexibility in scheduling the transfer, as it does not require ovarian stimulation and egg retrieval, which can be taxing on the body. This allows for optimal timing based on the woman’s natural cycle or preparation with hormone replacement therapy.

3. Reduced risk of ovarian hyperstimulation syndrome (OHSS): By freezing embryos and transferring them in a separate cycle, the risk of OHSS, a potential complication of ovarian stimulation during fresh IVF cycles, is minimized.

4. Cost-effectiveness: Utilizing frozen embryos from a previous IVF cycle can be more cost-effective compared to undergoing a full fresh IVF cycle, as it eliminates the need for another round of ovarian stimulation and egg retrieval.

5. Multiple transfer opportunities: If the first embryo transfer is unsuccessful, there may be additional frozen embryos available for subsequent transfer without the need to undergo another complete IVF cycle.

In summary