Blastocyst transfer extended embryo culture used to optimise pregnancy.
Blastocysts are embryos cultured in the laboratory for 5 or 6 days rather than the usual 2 or 3 days as in traditional IVF. A vital advantage is gained by allowing embryos to continue to this stage of development before embryo transfer, as it is a natural selection process, and shows us which embryos are the strongest and have the best chances of succeeding.
Also, in natural conception, the embryo fertilises in the Fallopian tube and does not arrive in the womb until the blastocyst stage. Hence a blastocyst transfer may be more ‘synchronised’ with the woman’s natural cycle. Blastocyst transfers correlate with higher implantation rates.
Blastocyst culture is particularly useful for younger women with a good prognosis for pregnancy from in vitro fertilisation (IVF).
Your doctor may also suggest you try blastocyst transfer if you have produced good quality embryos in a previous IVF cycle but they failed to implant in the womb.
Not all embryos will develop to produce blastocysts in the laboratory. Embryos can stop developing and progress no further. The embryologist may advise your consultant that in your case it is safer to consider a day two or three embryo transfer than risk having no blastocyst to transfer on day five or six.