Down-regulated Hormonally Controlled Cycles for Vitrification-warmed Blastocyst Transfers

Currently all patients that have freeze-all ICSI treatment cycles have the start of their FET cycle scheduled with the use of OCP. While an excellent pregnancy rate (75%) for the patients that have a blastocyst transfer has been maintained over time, 15% of started FET cycles are being cancelled because of premature luteinization, and the treatment (to transfer) takes approximately 89 days. The use of a Lucrin depot may reduce the number of cycles cancelled and reduce the treatment time to approximately 69 days. The use of no drugs and allowing the normal menstrual cycle to determine the time to start the FET cycle may suit some patients. Whether these benefits can be obtained while still maintaining the current FET pregnancy rate will be the main focus of the trial.