The most suitable embryo stage for transfer is the 5th to 6th day after the eggs have been fertilized by sperm. On this day, it is possible to either introduce the embryo into the uterus, called a fresh transfer, or freeze the embryo and introduce it into the uterus in the next cycle, called a cryoembryo transfer (CET).
In our clinic we prefer CET, as the success rate of cryoembryo transfer is usually higher than that of fresh transfer. The main reason is that in a cryocycle we are able to ensure that the uterine lining is better prepared to receive the embryo than in a fresh stimulated cycle. The timing of the transfer until the woman’s next natural cycle, which is no longer burdened by hormonal stimulation, also increases the success rate. For reasons of time, CET is the only option when using preimplantation embryo testing.
