TRANSFER OF PREVIOUSLY VITRIFIED EUPLOID EMBRYOS IN UNSTIMULATED MENSTRUAL CYCLES YIELDS HIGHER LIVE BIRTH RATES AND A LOWER INCIDENCE OF HYPERTENSIVE COMPLICATIONS COMPARED TO HORMONE REPLACEMENT CYCLES

Abstract

There has been a trend favoring freeze-all IVF cycles with subsequent frozen embryo transfer (FET) due to increased utilization of PGT, OHSS prevention, and reports of improved outcome with FET for some patients. FET may be performed in either a natural, unstimulated menstrual cycle or in a programmed cycle using hormone replacement therapy. Although several prior publications have demonstrated similar pregnancy rates between protocols, direct comparisons may be confounded due to heterogeneity within patient populations, particularly embryo quality and recipient age at oocyte retrieval.