Introduction
PROLIFERATIVE
Frozen Embryo Transfer (FET) cycles have increased ever since the first pregnancy from IVF using cryopreserved embryos was reported in 1983 [A thorough look at the current FET protocols is important to gain more insight towards an optimal FET strategy. FET can take place in either a natural cycle or in an artificial cycle [Nowadays, most FET-HRT protocols opt for the 14-day period of oestrogen supplementation to mimic the natural proliferative phase of the menstrual cycle [Besides the very open debate about the ideal length of the E2 supplementation and considering recent results showing that this has no effects on the FET outcome, we should consider another important issue of the FET cycle, which is the delayed time to pregnancy. A recent study on patients’ perspectives regarding elective FET (eFET) revealed that the postponement of embryo transfer is an important deciding factor in the choice of eFET versus fresh embryo transfer [