Fresh or Frozen Embryo Transfer in In Vitro Fertilization: An Update.

The past decade has witnessed a rapid increase in the number of frozen-thawed embryo transfer (FET) cycles. Several factors have contributed to the increase in FET cycles, including improvement in culture media, vitrification, and an increase in preimplantation genetic testing of embryos. However, the accelerated trend in FET cycles also suggests that FET may be preferred over fresh embryo transfer. The current review explores the factors that have influenced this practice shift toward preferential FET and why this shift may be premature.