Immediate Versus Delayed FET Following a Stimulated IVF Cycle

A Randomized Trial Comparing the Effect of Immediate Versus Delayed Frozen-thawed Embryo Transfer Following a Stimulated IVF Cycle

Information regarding the optimal timing for frozen-thawed embryo transfer (FET) following a stimulated in vitro fertilization (IVF) is lacking. One option is to perform FET in the first cycle following the stimulated IVF cycle, i.e. immediate transfer. Another option is to postpone FET for at least one menstrual cycle, i.e. delayed transfer. This randomized study aims to compare the ongoing pregnancy rate of immediate versus delayed FET following a stimulated IVF cycle.

Inclusion Criteria:

• Women aged ≤43 years at the time of IVF/ICSI treatment Undergoing IVF with a standard stimulation At least one frozen embryo or blastocyst The first FET cycle following ovarian stimulation in IVF/ICSI

Exclusion Criteria:

• Use of mild stimulation or natural cycle for IVF/ICSI treatment Severe ovarian hyperstimulation syndrome during IVF/ICSI treatment Preimplantation genetic diagnosis treatment Use of donor oocytes Presence of hydrosalpinx which is not surgically treated or endometrial polyp on scanning during ovarian stimulation