Embryo Transfer Timing
During natural cycles, transfer of frozen-thawed embryos is performed 2 days after ovulation. During artificial cycles, in women without menstrual cycle, embryo transfer is performed after estrogen and progesterone administration.
In natural cycles, the risk of suboptimal endometrial preparation, which may also occur in cases of ovarian hyperstimulation, is reduced.
There is clear evidence, that pregnancy rates increase if we add to the frozen embryos, the one that has been collected during a natural cycle. During natural cycles, oocyte retrieval is minimally invasive, painless and is done optionally without anesthesia. In cases of ovulation the optimal timing for cryopreserved embryo transfer, is decided after an ultrasound scan and hormonal blood tests have been performed, in order to diagnose ovulation.