Transfer of frozen embryos (TFE)
Technique
A frozen embryo transfer cycle is a quick and easy treatment which allows us to make use of the supernumerary embryos from an In Vitro Fertilization cycle (vitrified). In this way, we avoid the patient from starting an IVF cycle again, surgery, hormonal stimulation and all the rest of complex processes that this technique involves.
In this case, the medication used is only intended for preparing the endometrium of the patient (uterus), in order to have maximum receptivity at the moment of thawing and embryo transfer.
As there is no hormonal ovarian stimulation, this technique does not involve risk to human health and patient evolution, therefore it is not necessary a rest period as strict as it is in the case of IVF.
There are two kinds of protocol: the natural cycle (endometrial preparation following the natural cycle of a woman, without the need of external hormone administration), or the controlled cycle (exogenous hormone administration).
The treatment lasts between 12 and 15 days. Once the patient is prepared, the transfer will be done within the 48-72 hours after ultrasound control indicating a right endometrial receptivity.
The thawing (desvitrification) of the embryos takes place the day before or the same day of the transfer, depending on their stage of development.
The transfer is an easy procedure which is carried out in an outpatient setting and which consists in placing the embryos into a cannula, to later leave them inside the patient’s uterus through ultrasound visualization.
Fifteen days later a blood pregnancy test is performed to determine if pregnancy has been achieved.