Cryopreservation of embryos is considered an important step for the success of  IVF treatment, because often the method known as “freeze-all”, a term in English that means freezing all embryos to transfer in a later cycle, it is necessary to be used to increase the chances of successful treatment. During controlled ovarian stimulation, the woman is subjected to supra-physiological concentrations of hormones. There is scientific evidence that high exposure of female hormones has a toxic effect on the embryo, changing the receptivity of the endometrium and the formation of the placenta.

Scientific studies prove that women who use frozen embryos in IVF treatments may have a greater chance of success compared to those who use fresh embryos.

The current results show several benefits for FET (Transfer of thawed embryos), which are:

• Increase in implantation rates
• Increased pregnancy rates
• Decreases abortion rates
• Less chance of bleeding during pregnancy
• Babies are born with greater weight
• Decreases the risk of premature birth

The preparation to perform the FET is much simpler, there is no high exposure of hormones, because the preparation of the endometrium can be performed in a natural cycle. The medications used are not injectable, on the other hand, they are oral or transdermal and in lesser quantity. In this way, the synchronization of the embryo with the uterus increases, since the preparation of the endometrium is carried out in a more natural environment similar and compatible with spontaneous pregnancy.