We are increasingly culturing embryos for more than 3 days.
A blastocyst is the developmental stage that an embryo normally reaches 5-6 days after fertilisation. A blastocyst consists of approximately 100 cells. Blastocysts consist of a fluid-filled centre surrounded by a wall of cells. A small group of cells on the inner side of the wall (‘the inner cell mass’) are those cells that will develop into the embryo. Embryos in the blastocyst stage hatch out of the surrounding ‘egg-shell’ (‘zona pellucida’) and begin to implant in the endometrium around 6-7 days after fertilisation.
With a high performance laboratory, it is possible to obtain significantly higher pregnancy rates per transferred embryo with longer (blastocyst) culture than with transfer on day 3. Embryo culture beyond 3 days demands a very high level of precision in the laboratory, specialised culture media, and very well defined constant conditions such as temperature and gas composition in the incubators.
We have spent a lot of effort optimising our blastocyst cultures. We use the best available culture media and we culture the embryos at low oxygen tension in order to mimic the environment in the fallopian tube.
For blastocyst culture, it is desirable that there are five or more good quality embryos on day 3 after the oocyte pick-up. During the culture period, the laboratory will keep you informed about the development of your embryos on their way towards the blastocyst stage.
Tel: +45 39 40 70 00