REASONS FOR CRYOPRESERVATION
At ReproART, we will generally transfer no more than two embryos to the uterus, even when extra excellent embryos are available. In programs with excellent IVF success such as we have, transfer of more than 2 embryo does not improve chances of pregnancy but does increase the risk of multiple pregnancy, especially triplet pregnancy. (Multiple pregnancy is more dangerous than singleton pregnancy for both the mother and the baby.) Consequently, we cryopreserve (freeze) the attractive embryos remaining after any transfer.
In some cases, when your doctor believes that the uterus is not sufficiently ready, or when progesterone levels are elevated, we may wish to delay your embryo transfer by at least one month and to cryopreserve all of your embryos. Our experience has taught us that success is better using frozen embryos in a later cycle then it is using fresh embryos when the uterus is impaired.
METHODS FOR CRYOPRESERVATION
Remarkable progress has occurred in recent years for embryo-freezing methods. Relevant equipment and freezing solutions. The new methods involve a new technique of cryopreservation called vitrification. Similar to many leading global clinics, ReproART achieves much higher rates of survival for embryos that have been vitrified.
Vitrification involves incubating embryos in special cryoprotectant solutions, followed by rapid cooling in liquid nitrogen at -1960C.
SUCCESS WITH CRYOPRESERVED EMBRYOS
We have found that transfer of vitrified embryos during frozen embryo cycles results in better pregnancy success than transfer of fresh (unfrozen) embryos during the aspiration cycle. We believe the use of low hormone levels used during natural or programmed cycles to prepare the uterus for a frozen embryo cycle is more successful for pregnancy than the extraordinarily high hormone levels achieved during ovarian stimulation for oocyte retrieval. The survival rate of thawed blastocysts at ReproART is 98% and pregnancy rates after their transfer average 64.5%.
ReproART’s results using frozen/thawed embryos were presented at the 2015 Congress of the European Society of Human Reproduction and Embryology in Lisbon, Portugal.
To plan consultations with ReproART Fertility Specialist, please set an appointment in advance or request more information.