Non-inferiority of cleavage-stage versus blastocyst-stage embryo transfer in poor prognosis IVF patients (PRECiSE trial): study protocol for a randomized controlled trial

摘要

Study design flow diagram. First cycle IVF patients meeting inclusion criteria will be consented to participate in the study and undergo an autologous IVF cycle. Patients who consent to participate in the study may be determined ineligible prior to randomization depending on the number of available embryos on day 1 post fertilization. After allocation to cleavage-stage or blastocyst-stage fresh embryo transfer patients will receive standard care and any embryos not transferred will be cryopreserved at the blastocyst stage. If pregnancy is not achieved in the fresh transfer cycle any remaining frozen embryos will be transferred. All pregnant patients will be followed and pregnancy outcomes recorded. To investigate pregnancy outcomes per IVF retrieval we will follow participants until all cryopreserved embryos have been transferred or a transfer results in a live birth, whichever occurs first