Normally, for women under the age of 35 who are undergoing Assisted Reproductive treatment for the first time, it is advisable not to transfer more than two embryos during the treatment cycle. Among the embryos produced during the IVF or ICSI procedure, the best (according to technical criteria related to morphological and developmental characteristics) are selected to be transferred to the uterus, with the remaining embryos being cryopreserved - provided that they are also considered viable and have the conditions to be used in future treatment.
Embryos are cryopreserved in liquid nitrogen, at -196 ºC which enables them to be available for later use (if the patients decide to have a second child or in case the first treatment does not have a positive result). Cryopreservation of embryos means that if a new treatment cycle is decided it is not necessary to go through the expensive and sometimes difficult process of ovarian stimulation, oocyte pickup and subsequent fertilisation by ICSI or IVF method. Also, in cycles with cryopreserved embryos, there are no risks related to the use of ovulation-stimulating drugs or the risk of Ovarian Hyperstimulation Syndrome.
The decision on the destination of cryopreserved embryos is the responsibility of the person(s) performing the ART treatment: they may be used in a new attempt; may be donated to the other beneficiary(s) of this treatment; may be donated for scientific research; or can be destroyed.
In any case, it is always up to the person(s) performing the treatment to decide on the destination of the cryopreserved embryos, which can be stored for a maximum period of three years (renewable for a further three).
Ferticentro establishes regular contact with all patients whose embryos are stored in our cryopreservation containers. It is therefore important that you keep your contact information up to date with the clinic, informing us of any changes in contact details.
In order for cryopreservation to occur, the embryos are stored inside a special cryoprotectant liquid, which protects them against any damages that the cryopreservation process may cause.
It should be noted that not all embryos are likely to be cryopreserved: only those that have developed normally and do not show significant levels of fragmentation will be able to go through the process of freezing and thawing. Also important is the notion that, even with all safety precautions, there are embryos that do not survive the thawing process for use in a new treatment cycle. For this reason, it may be necessary to thaw more embryos than those likely to be transferred in FET treatment cycles.
Embryos that survive the process of freezing and thawing may be implanted in the uterus as if they were transferred fresh.