Frozen embryo transfer preparation

The increased use of embryo freezing has placed greater emphasis on techniques and protocols regarding frozen-thawed embryo transfer (FET). While no one method has emerged as the superior choice, the various strategies in use each have their own benefits as well as drawbacks. Natural cycle FET allows a more physiologic and potentially less expensive way of transferring embryos at the cost of cycle unpredictability which many clinics may not be able to accommodate. Artificial cycle FET allows more control over embryo thawing and transfer but requires use of additional medications which invariably increase cost and side effects. Limited number of embryos obtained from patients with diminished ovarian reserve and/or advanced reproductive age makes FET preparation and monitoring of the utmost importance. In the future, further studies involving exclusively frozen cycles with the inclusion of diverse patient subgroups will hopefully offer guidance as to the most optimal FET protocol to use.