Transfer of cryopreserved embryos: natural cycle vs. Hormone Replacement Therapy (HRT)

Transfer of cryopreserved embryos: An effective and safe technique

The development of vitrification (ultra-rapid freezing) technology for embryo freezing is the factor that has contributed most to improving the results and safety of in vitro fertilisation over the last decade. As a result, there has been a significant increase in the number of transfer of cryopreserved embryos in daily clinical practice.

The great advantage of this process is that pregnancy rates are the same as those for fresh embryo transfer, but without the drawbacks of ovarian stimulation treatment (economic cost, risk of hyperstimulation syndrome, psychological distress, etc.). This makes the transfer of cryopreserved embryos a more comfortable and equally effective alternative for many patients.

This treatment, which is essential in IVF to obtain several eggs and multiple embryo development in order to optimise the process, becomes unnecessary in transfer of cryopreserved embryos. For this, only a suitable endometrium synchronised in its development with the embryo to be transferred is required. This endometrial state can be achieved simply spontaneously, during a woman’s normal ovulatory cycle (natural cycle), or induced, with the sequential administration of oestradiol and progesterone hormones. This is what we call Hormone Replacement Therapy (HRT).

Both methods of endometrial preparation have been shown to be equally effective in terms of results. Therefore, at URE Centro Gutenberg, the choice of one or the other will be based exclusively on medical criteria, as well as the comfort and safety of the patient. That is why, whenever an adequate ovarian cycle is available, endometrial preparation using the natural cycle is the option most often chosen for our patients.