Blastocyst transfer

Blastocysts are embryos with 64 to > 200 cells. This stage is reached by embryos on the 5th day after the follicle puncture by optimum development.


A blastocyst has a very high likelihood (about 35%) to establish itself and can lead to a pregnancy. This is the reason, why many countries prefer to carry out the embryo culture up to the blastocyst-stage.


Through the high pregnancy likelihood with are transfer of embryos in the blastocyst-stage, two or even only one embryo is transferred in a normal case. Thereby, triplet pregnancies can almost be excluded and twin pregnancies clearly reduced.


However, unfortunately, only one third of all fertilised ova develop to a blastocyst. In many countries this is no problem. In these countries the least number of fertilised ova are let to grow and on day 5 ordinarily at least one blastocyst exists.


In Germany it is written by law (see Protection Law for Embryos), that only three fertilised ova may develop to an embryo. These have to be already selected on the day of the winning of ova, meaning before the first cell division.


For this reason a blastocyst culture can not lead to a clear rise of pregnancy likelihood in Germany. But for this the blastocyst culture also offers us an advantage. Not only the success of the running therapy allows a better estimation, but also the diagnostic instrument which gives a better calculation on the possible following attempts of realisation or amount of transferred embryos.




Further to