Blastocyst transfer represents the process of transferring the day 5 embryos. At this point is easier to choose the healthy embryos to be transferred to the uterus. The blastocyst transfer has become more and more popular and is a better alternative of transferring the day 3 embryos. Below you can see the picture of a blastocyst.
When the embryo reaches the development stage of 5-7 days after the fertilization it is called blastocyst. At this point the blastocyst divides in two types of cells: an inner core which will transform later in the fetus and an external lining which will become the placenta. If the process devolves normally the blastocyst should come out from its shell in the 6th day and should begin the implantation 24 hours after that.
Recent researches show that embryos which aren’t able to survive the blastocyst phase have an abnormal number of chromosome.
Advantages of blastocyst transfer:
-the biggest advantage is probably that a small number of embryos are required for the transfer due to the fact that the blastocysts are healthy embryos and the chance of multiple pregnancy is reduced. The maximum number of embryos that are transferred is 2. There are many patients who follow the blastocyst transfer because this way many dangers are avoided: miscarriages, giving birth to low weight babies, stillbirth.
– the blasocysts are transferred to the uterus at the time that the embryos would have entered into the uterus in a natural way. Unlike the day 3 embryo transfer that takes place at the time when the embryos should be still in the fallopian tubes. That is why the blastocyst transfer is a more natural way of fertilization.
-due to the fact that embryos are allowed to develop for a longer period of time, it is easier to establish which embryos are healthy and ready to be transferred into the uterus.
The success rate of the in vitro fertilization procedure has increased with the blastocyst embryo transfer.
Disadvantages of blastocyst transfer:
couples can loose a large number of embryos because many of them don’t survive the blastocyst stage.
-blastocyst embryos require a very well equipped laboratory and special attention because they need a certain temperature and special conditions.
– if couples decide to freeze their embryos they can only do that with day 3 embryos, blastocysts can’t survive the cryopreservation.
Not all couples are suitable for blastocyst transfer. They should consider this procedure the couples who have a small number of embryos for transferring or who didn’t succeeded a previous day 3 embryos transfer or women who need to avoid multiple pregnancy because their health state does not allow it.